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Harlequin Ichthyosis

Table of Contents

Harlequin Ichthyosis

HI; Harlequin Baby Syndrome; Harlequin Fetus; Harlequin-Type Ichthyosis; Ichthyosis Congenita Harlequin Fetus Type

Harlequin ichthyosis is a severe genetic disorder that mainly affects the skin. Infants with this condition are born with very hard, thick skin covering most of their bodies. Explore symptoms, causes, and genetics of this rare disorder.

Genetic Translocation

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Harlequin ichthyosis

Image by Fouad, Adil; Bennaoui, Fatiha; Slitine, Nadia El Idrissi; Soraa, Nabila; Maoulainine, F. M. R./Wikimedia

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Harlequin ichthyosis

Harlequin ichthyosis in a female infant

Image by Fouad, Adil; Bennaoui, Fatiha; Slitine, Nadia El Idrissi; Soraa, Nabila; Maoulainine, F. M. R./Wikimedia

What Is Harlequin Ichthyosis?

Harlequin ichthyosis is a severe genetic disorder that affects the skin. Infants with this condition are born prematurely with very hard, thick skin covering most of their bodies. The skin forms large, diamond-shaped plates that are separated by deep cracks (fissures). These skin abnormalities affect the shape of the eyelids, nose, mouth, and ears, and limit movement of the arms and legs. Restricted movement of the chest can lead to breathing difficulties and respiratory failure in babies with harlequin ichthyosis. Affected infants also have feeding problems.

The skin normally forms a protective barrier between the body and its surrounding environment. The skin abnormalities associated with harlequin ichthyosis disrupt this barrier, making it difficult for affected infants to control water loss, regulate their body temperature, and fight infections. Infants with harlequin ichthyosis often experience an excessive loss of fluids (dehydration) and develop life-threatening infections in the first few weeks of life.

Following the newborn period, the hard, skin plates are shed and the skin develops widespread scales and redness.

It used to be very rare for affected infants to survive the newborn period. However, with intensive medical support and improved treatment, babies with this disorder now have a better chance of living into childhood and early adulthood.

Source: MedlinePlus Genetics

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Ectropion, open mouth and thick lips seen. Emollients applied and the baby covered with sterile gauze

Image by Belide Shruthi,1,* B.R. Nilgar,1 Anita Dalal,1 and Nehaben Limbani1/Wikimedia

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3-year-old female with harlequin ichthyosis, the keratin scales having almost completely fallen off

Image by Dubey, Alok Kumar; Tuibeqa, Ilisapeci Vereti; Pio, Nina BaivouStretching applied by User:SUM1./Wikimedia

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TJOD-14-138-g3

Belide Shruthi,1,* B.R. Nilgar,1 Anita Dalal,1 and Nehaben Limbani1/Wikimedia

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Harlequin ichthyosis (2)

Dubey, Alok Kumar; Tuibeqa, Ilisapeci Vereti; Pio, Nina BaivouStretching applied by User:SUM1./Wikimedia

Causes

Mutation

Image by National Human Genome Research Institute (NHGRI)

Mutation

A mutation is a change in the DNA sequence of an organism. Mutations can result from errors in DNA replication during cell division, exposure to mutagens or a viral infection. Germline mutations (that occur in eggs and sperm) can be passed on to offspring, while somatic mutations (that occur in body cells) are not passed on.

Image by National Human Genome Research Institute (NHGRI)

What Causes Harlequin Ichthyosis?

Variants (also known as mutations) in the ABCA12 gene cause harlequin ichthyosis. The ABCA12 gene provides instructions for making a protein that is essential for the normal development of skin cells. This protein plays a major role in the transport of fats (lipids) and enzymes in the outermost layer of skin (the epidermis).

Some variants in the ABCA12 gene prevent the cell from making any ABCA12 protein. Other variants lead to the production of an abnormally small version of the protein that cannot transport lipids properly. A loss of functional ABCA12 protein disrupts the normal development of the epidermis before and after birth, resulting in the severe skin abnormalities characteristic of harlequin ichthyosis.

Source: MedlinePlus Genetics

ABCA12 Gene

Ideogram of human chromosome 2

Image by Office of Biological and Environmental Research of the U.S. Department of Energy Office of Science, the Biological and Environmental Research Information System, Oak Ridge National Laboratory.

Ideogram of human chromosome 2

Selected genes, traits, and disorders associated with the chromosome listed; (blue and violet) regions reflecting the unique patterns of light and dark bands seen on human chromosomes stained to allow viewing through a light microscope; (red) the centromere, or constricted portion, of each chromosome; (yellow) chromosomal regions that vary in staining intensity and sometimes are called hererochromatin (meaning “different color”); (lines between yellow) variable regions, called stalks, that connect a very small chromosome arm (a “satellite”) to the chromosome.

Image by Office of Biological and Environmental Research of the U.S. Department of Energy Office of Science, the Biological and Environmental Research Information System, Oak Ridge National Laboratory.

ABCA12 Gene: ATP Binding Cassette Subfamily A Member 12

Normal Function

The ABCA12 gene provides instructions for making a protein known as an ATP-binding cassette (ABC) transporter. ABC transporter proteins carry many types of molecules across cell membranes. In particular, the ABCA12 protein plays a major role in transporting fats (lipids) and enzymes in cells that make up the outermost layer of skin (the epidermis). This transport of molecules is needed to maintain the layers of lipids within the epidermis that are necessary to prevent water loss (dehydration) and for normal development of the skin.

Health Conditions Related to Genetic Changes

Harlequin ichthyosis

Many variants (also known as mutations) in the ABCA12 gene have been identified in people with harlequin ichthyosis. This skin condition is characterized by hard, thick scales that are present at birth; excessive dehydration; and increased risk of infections.

Most ABCA12 gene variants result in the production of an abnormally short protein that cannot transport lipids properly. Individuals with ABCA12 gene variants that result in a complete absense of ABCA12 protein often have the most severe skin problems and tend not to survive past infancy. In people with abnormal or nonfunctional ABCA12 protein, a lack of lipid transport causes numerous problems with the development of the epidermis before and after birth. Specifically, it prevents the skin from forming an effective barrier, and leads to the skin problems characteristic of harlequin ichthyosis.

Nonbullous congenital ichthyosiform erythroderma

Variants in the ABCA12 gene have been found to cause nonbullous congenital ichthyosiform erythroderma (NBCIE). This condition affects the skin and causes redness; the development of fine, white scales; an increased risk of infections; and dehydration. These skin abnormalities tend to be less severe than those in harlequin ichthyosis (described above).

Most of the variants that cause NBCIE change single protein building blocks (amino acids) in the ABCA12 protein. These variants likely lead to the production of a protein with reduced function, which impairs lipid transport and the formation of the lipid layers within the epidermis. Problems with this protective barrier underlie the skin abnormalities and other features of NBCIE.

Lamellar ichthyosis

MedlinePlus Genetics provides information about Lamellar ichthyosis

Other Names for This Gene

ABCAC_HUMAN
ATP-binding cassette 12
ATP-binding cassette transporter 12
ATP-binding cassette, sub-family A (ABC1), member 12
ATP-binding cassette, sub-family A, member 12
ICR2B

Genomic Location

The ABCA12 gene is found on chromosome 2.

Source: MedlinePlus Genetics

Inheritance

Newborn autosomal recessive pattern of inheritance

Image by Thomas Shafee and TheVisualMD

Newborn autosomal recessive pattern of inheritance

Newborn autosomal recessive pattern of inheritance

Image by Thomas Shafee and TheVisualMD

How Is Harlequin Ichthyosis Inherited?

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have variants. The parents of an individual with an autosomal recessive condition each carry one copy of the altered gene, but they typically do not show signs and symptoms of the condition.

Source: MedlinePlus Genetics

Diagnosis

Amniocentesis

Image by TheVisualMD

Amniocentesis

Amniocentesis is a prenatal test that gathers information about a fetus` health from a sample of amniotic fluid. Amniotic fluid is the fluid that surrounds the fetus in the uterus. It contains cells from the fetus that naturally slough off during development. If a woman is at high risk for a genetic disease, a doctor may recommend an "amnio" to determine whether a fetus has certain genetic disorders, such as cystic fibrosis, among other diseases.

Image by TheVisualMD

How Is Harlequin Ichthyosis Diagnosed?

Yes, harlequin ichthyosis can be diagnosed before birth using either amniocentesis or chorionic villus sampling. Both of these procedures are used to obtain a sample of fetal DNA, which can be tested for mutations in the ABCA12 gene. Patients and consumers with specific questions about a specific genetic test should contact a health care provider or a genetics professional.

Source: Genetic and Rare Diseases (GARD) Information Center

Amniocentesis

Amniocentesis

Also called: Amnio, Amniotic Fluid Test, AFT, Amniotic Fluid Analysis

Amniocentesis is a test done during pregnancy, usually between weeks 15 and 20. It uses a sample of amniotic fluid to diagnose certain genetic disorders, birth defects, and other health problems in an unborn baby.

Amniocentesis

Also called: Amnio, Amniotic Fluid Test, AFT, Amniotic Fluid Analysis

Amniocentesis is a test done during pregnancy, usually between weeks 15 and 20. It uses a sample of amniotic fluid to diagnose certain genetic disorders, birth defects, and other health problems in an unborn baby.

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Use the slider below to see how your results affect your health.
Your result is Normal.
A normal or negative result means that there were 46 chromosomes in the sample without any unusual changes in their structure. Normal karyotypes for females contain two X chromosomes and are denoted 46,XX; males have both an X and a Y chromosome denoted 46,XY.
Related conditions
Amniocentesis is used to diagnose certain health problems in an unborn baby. It is commonly used to find:
- Genetic and chromosomal disorders, including:
  Down syndrome, a disorder that causes intellectual disabilities and other health problems
  Cystic fibrosis, a disease of the mucus and sweat glands that causes thick sticky mucus, which can lead to problems with breathing and digestion
  Sickle cell disease, a group of red blood cell disorders that can cause anemia and other health problems
  Tay-Sachs disease, a disease that destroys nerve cells, causes mental and physical problems, and often death in early childhood (uncommon)
- Neural tube defects, severe birth defects of the baby's brain and/or spine, such as spina bifida and anencephaly.
The test may also be used to:
- Check your baby's lung development if you have a risk for giving birth too soon (premature birth). In this case, amniocentesis is done later in pregnancy.
- Diagnose an infection or certain other illnesses in the baby
Having amniocentesis is your choice. You may want this test if you have a high risk for having a baby with a health problem. You may have an increased risk if:
- You are age 35 or older. (The risk of having a baby with a genetic disorder increases with age.)
- You had a prenatal screening test that shows your baby might have a problem.
- You or your partner have a family history of a genetic disorder or neural tube defect.
- You or your partner had genetic testing that showed you carry a genetic disorder.
- You or your partner have a child with a genetic disorder or birth defect.
Amniocentesis isn't right for everyone. Before you decide to get tested, think about how you'd feel and what you might do after learning the results.
The test is usually done between 15 and 20 weeks of pregnancy. It is sometimes done later in pregnancy to check the baby's lung development or diagnose certain infections or illnesses, such as anemia in the unborn baby caused by Rh incompatibility.
During the procedure:
- You'll lie on your back on an exam table.
- Your provider may apply a numbing medicine to your abdomen.
- Your provider will move an ultrasound wand-like device, called a transducer, on your belly. Ultrasound uses sound waves to show the position of your baby and placenta so your provider can see where to take a sample of amniotic fluid.
- Your provider will insert a thin needle into your abdomen and withdraw a small amount of amniotic fluid.
- When the sample is removed, your provider will check your baby's heartbeat with the ultrasound.
The procedure usually takes about 15 minutes. Afterwards, you may be told to avoid any hard exercise or physical activity for the next 24 hours.
Amniotic fluid may be tested for many different disorders. Your test results will depend on which tests your provider ordered.
- Normal results are reported as "normal" or "negative." This means that it's very unlikely that your baby has the disorder that was tested, but it does not guarantee your baby will not have any health problems.
- Results that are not normal are reported as "abnormal" or "positive." This means that your baby very likely has the disorder that was tested.
Your provider will explain your test results. Amniocentesis is very accurate, but in certain cases, your provider may order more tests to learn about your baby's health.
It may help to speak to a genetic counselor before testing and/or after you get your results. A genetic counselor is a specially trained professional in genetics and genetic testing who can help you understand what your results mean.
1. Amniocentesis (amniotic fluid test): MedlinePlus Medical Test [accessed on Jan 20, 2024]
2. Amniocentesis: MedlinePlus Medical Encyclopedia [accessed on Jan 17, 2019]
3. Diagnosis of Birth Defects | CDC [accessed on Jan 17, 2019]
4. Amniocentesis. Test in pregnancy, amniocentesis information. | Patient [accessed on Jan 17, 2019]
5. Amniocentesis - Health Encyclopedia - University of Rochester Medical Center [accessed on Jan 17, 2019]
6. Amniotic Fluid Analysis [accessed on Jan 17, 2019]
7. Amniocentesis - InsideRadiology [accessed on Jan 17, 2019]
8. Amniocentesis - NHS [accessed on Jan 17, 2019]
9. Amniocentesis - American Pregnancy Association [accessed on Jan 17, 2019]
10. Amniocentesis Procedure [accessed on Jan 17, 2019]
11. Amniocentesis | March of Dimes [accessed on Jan 17, 2019]

Additional Materials (10)

Amniocentesis

Amniocentesis

Image by TheVisualMD

Amniocentesis Being Performed on Human Pregnancy

Amniocentesis Being Performed on Human Pregnancy

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Amniocentesis

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Amniocentesis: Pre-Baby Care (Pregnancy Health Guru)

Video by Healthguru/YouTube

Amniocentesis | Parents

Video by Parents/YouTube

This browser does not support the video element.

Prenatal Diagnostic Testing

If a pregnant woman has an abnormal genetic screening test result, a doctor may suggest a prenatal diagnostic test be done to determine with more certainly whether or not a fetus has a particular disorder. There are two main diagnostic testing procedures, chorionic villus sampling (CVS) and amniocentesis. Both of these tests involve collecting a sample from inside the womb, which is then examined to detect diseases such as Down Syndrome, Edwards Syndrome, neural tube defects, cystic fibrosis, fragile-x, and spinal muscular atrophy. Prenatal diagnostic tests provide valuable information on the health of the fetus and can help alleviate the stress of expectant parents.

Video by TheVisualMD

Genetic Testing During Pregnancy

Video by University of California Television (UCTV)/YouTube

Amniocentesis.flv

Video by PortalMedicoModerno/YouTube

Amnio vs. Genetic Blood Testing

Video by Lee Health/YouTube

Amniocentesis

Video by Washington State Department of Health/YouTube

Amniocentesis

TheVisualMD

Amniocentesis Being Performed on Human Pregnancy

TheVisualMD

3:15

Amniocentesis

Obstetrics & Gynecology Associates/YouTube

2:01

Amniocentesis: Pre-Baby Care (Pregnancy Health Guru)

Healthguru/YouTube

4:57

Amniocentesis | Parents

Parents/YouTube

4:34

Prenatal Diagnostic Testing

TheVisualMD

4:38

Genetic Testing During Pregnancy

University of California Television (UCTV)/YouTube

0:49

Amniocentesis.flv

PortalMedicoModerno/YouTube

1:56

Amnio vs. Genetic Blood Testing

Lee Health/YouTube

3:44

Amniocentesis

Washington State Department of Health/YouTube

Chorionic Villus Sampling

Chorionic Villus Sampling

Also called: CVS, Chorionic Villus Biopsy, Placental Biopsy

Chorionic villus sampling (CVS) is a test for pregnant women that checks cells from the placenta. It is used in the first trimester of pregnancy to diagnose certain chromosome and genetic disorders in an unborn baby.

Chorionic Villus Sampling

Also called: CVS, Chorionic Villus Biopsy, Placental Biopsy

Chorionic villus sampling (CVS) is a test for pregnant women that checks cells from the placenta. It is used in the first trimester of pregnancy to diagnose certain chromosome and genetic disorders in an unborn baby.

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Use the slider below to see how your results affect your health.
Your result is Normal.
A normal result means that no signs of chromosomal or genetic defects were detected in your developing baby.
Related conditions
CVS testing is used to diagnose chromosome problems or other genetic diseases in an unborn baby. These include:
- Down syndrome, a disorder that causes intellectual disabilities, certain physical features, and various health problems.
- Cystic fibrosis, a disease that causes mucus buildup in the lungs and other organs, making it hard to breathe.
- Sickle cell disease, a disorder of the red blood cells. It can cause pain, infections, organ damage, and strokes.
- Tay-Sachs disease, a disorder that causes fatty proteins to build up in the brain. It affects sight, hearing, and mental development. Most children with Tay-Sachs die by the age of 5.
CVS testing is very accurate and can be done early in pregnancy, between the 10th and 13th week. But it can only diagnose certain genetic diseases. A CVS test does not diagnose or screen for birth defects such as neural tube defects, conditions that cause abnormal development of a developing baby's brain and/or spine. Different tests, including an alpha-fetoprotein (AFP) blood test, are used to screen for or diagnose these and other birth defects.
You may need CVS testing if you are at higher risk for having a baby with a chromosome disorder. Risk factors include:
- Age. Women age 35 and older have a higher risk of having a baby with Down syndrome or another genetic disorder.
- Family history of a genetic disorder
- Having another child with a genetic disorder
You may also need CVS testing if you had abnormal results on a prenatal screening test.
There are two types of CVS tests:
- Transabdominal The sample is taken through the abdomen.
- Transcervical. The sample is taken through the cervix. The cervix is the lower, narrow end of the uterus that opens into the vagina.
Your provider will use an ultrasound to check your baby's position and guide the procedure (transabdominal or transcervical). Ultrasound is an imaging test that uses sound waves to create pictures.
During a transabdominal CVS, your provider will:
- Clean your abdomen with an antiseptic.
- Apply a numbing medicine to your abdomen.
- Insert a long, thin needle through your abdomen and uterus and into the placenta. You may feel a cramping or stinging sensation as the needle enters the uterus.
- Use the needle to withdraw a sample of tissue from the placenta.
- Remove the needle.
During a transcervical CVS, your provider will:
- Clean your vagina and cervix with an antiseptic
- Use an instrument called a speculum to gently spread apart the sides of your vagina.
- Insert a thin tube through your vagina and cervix and up to the placenta. You may feel a slight twinge or cramping as this is done.
- Use the tube to gently suck in a sample of tissue from the placenta.
- Remove the tube.
CVS is generally considered to be a safe procedure, but it does have some risks. These include:
- Miscarriage, which happens in about one in every hundred procedures
- Infection
- Bleeding
- Rh sensitization. This is a condition in which your body makes antibodies (proteins made by the immune system) that attack your baby's red blood cells. If diagnosed during pregnancy, it is easily treatable.
- Limb defects in the baby (this is very rare)
1. http://americanpregnancy.org/prenatal-testing/chorionic-villus-sampling/ [accessed on Jan 26, 2019]
2. https://medlineplus.gov/ency/article/003406.htm [accessed on Sep 18, 2019]
3. https://medlineplus.gov/lab-tests/down-syndrome-tests/ [accessed on Sep 18, 2019]
4. https://www.cdc.gov/ncbddd/birthdefects/diagnosis.html [accessed on Sep 18, 2019]
5. https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/chorionic-villus-sampling-cvs [accessed on Sep 18, 2019]

Normal reference ranges can vary depending on the laboratory and the method used for testing. You must use the range supplied by the laboratory that performed your test to evaluate whether your results are "within normal limits."

Additional Materials (14)

Chorionic Villus Sampling

Video by manny1976/YouTube

Chorionic Villus Sampling (CVS)

Video by Washington State Department of Health/YouTube

Prenatal screening, fetal testing, and other tests during pregnancy

Video by MedLecturesMadeEasy/YouTube

This browser does not support the video element.

Prenatal Diagnostic Testing

If a pregnant woman has an abnormal genetic screening test result, a doctor may suggest a prenatal diagnostic test be done to determine with more certainly whether or not a fetus has a particular disorder. There are two main diagnostic testing procedures, chorionic villus sampling (CVS) and amniocentesis. Both of these tests involve collecting a sample from inside the womb, which is then examined to detect diseases such as Down Syndrome, Edwards Syndrome, neural tube defects, cystic fibrosis, fragile-x, and spinal muscular atrophy. Prenatal diagnostic tests provide valuable information on the health of the fetus and can help alleviate the stress of expectant parents.

Video by TheVisualMD

Diagnostic Testing in Pregnancy

Video by Michigan Medicine/YouTube

Prenatal Testing - What You Need To Know

Video by Rehealthify/YouTube

Amniocentesis: Pre-Baby Care (Pregnancy Health Guru)

Video by Healthguru/YouTube

Chorionic Villus Sampling (CVS) Mnemonic

Video by Medicosis Perfectionalis/YouTube

First Trimester of Pregnancy -- CVS Prenatal Test | Parents

Video by Parents/YouTube

Genetic Testing During Pregnancy

Video by University of California Television (UCTV)/YouTube

Prenatal Screening Options: Chorionic Villus Sampling (CVS)

Video by UNC Center for Maternal and Infant Health/YouTube

Embryo 26 Day Old (Week 5 for Gestational Age) Suspended in Chorionic Cavity

Computer Generated Image from Micro-MRI, actual size of embryo = 4.0 mm - This image presents a right-sided view of the embryo during its fourth week of embryonic development. The age is calculated from the day of fertilization. At the beginning of the 4th week, the heart begins to beat and the embryonic circulation sets in. At the end of 4 weeks over 30 somites are present . Somites are paired blocks of cells which in the later stages of development give rise to connective tissue, bone, muscle and the spine. The embryo is suspended in the protective chorionic cavity by the body stalk (the amniotic cavity and yolk sac have been removed to demonstrate the C-shaped curvature of the embryo). The red spot in the head region indicates the developing eye.

Image by TheVisualMD

Chorionic villi

Chorionic villus

Image by BruceBlaus

Chorionic villi

Schematic view of the placenta and chorion.

Image by Swils6

4:42

Chorionic Villus Sampling

manny1976/YouTube

4:16

Chorionic Villus Sampling (CVS)

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18:42

Prenatal screening, fetal testing, and other tests during pregnancy

MedLecturesMadeEasy/YouTube

4:34

Prenatal Diagnostic Testing

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2:10

Diagnostic Testing in Pregnancy

Michigan Medicine/YouTube

1:45

Prenatal Testing - What You Need To Know

Rehealthify/YouTube

2:01

Amniocentesis: Pre-Baby Care (Pregnancy Health Guru)

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2:13

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2:44

First Trimester of Pregnancy -- CVS Prenatal Test | Parents

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4:38

Genetic Testing During Pregnancy

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5:18

Prenatal Screening Options: Chorionic Villus Sampling (CVS)

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Embryo 26 Day Old (Week 5 for Gestational Age) Suspended in Chorionic Cavity

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Genetic Testing

Genetic Testing

Also called: DNA Testing, Mutation Screening, Genetic Test

Genetic testing is a type of test that analyze your cells or tissue to look for any changes in your DNA. Genetic tests may be used to identify increased risks of health problems, to choose treatments, or to assess responses to treatments.

Genetic Testing

Also called: DNA Testing, Mutation Screening, Genetic Test

Genetic testing is a type of test that analyze your cells or tissue to look for any changes in your DNA. Genetic tests may be used to identify increased risks of health problems, to choose treatments, or to assess responses to treatments.

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Use the slider below to see how your results affect your health.
Your result is Negative.
A negative result means that the test did not find a genetic change known to cause disease.
Related conditions
Genetic testing may be done for many different reasons, including to:
- Find genetic diseases in unborn babies. This is one type of prenatal testing.
- Screen newborn babies for certain treatable conditions
- Lower the risk of genetic diseases in embryos that were created using assisted reproductive technology
- Find out if you carry a gene for a certain disease that could be passed on to your children. This is called carrier testing.
- See whether you are at increased risk of developing a specific disease. This may be done for a disease that runs in your family.
- Diagnose certain diseases
- Identify genetic changes that may be causing or contributing to a disease that you were already diagnosed with
- Figure out how severe a disease is
- Help guide your doctor in deciding the best medicine and dosage for you. This is called pharmacogenomic testing.
There are no known risks to having a saliva test. There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
The physical risks of the different types of genetic testing are small. But there can be emotional, social, or financial drawbacks:
- Depending on the results, you may feel angry, depressed, anxious, or guilty. This can be especially true if you are diagnosed with a disease that does not have effective treatments.
- You may be worried about genetic discrimination in employment or insurance
- Genetic testing may give you limited information about a genetic disease. For example, it cannot tell you whether you will have symptoms, how severe a disease might be, or whether a disease will get worse over time.
- Some genetic tests are expensive, and health insurance might only cover part of the cost. Or they may not cover it at all.
- Positive – the test found a genetic change known to cause disease.
- Negative – the test did not find a genetic change known to cause disease. Sometimes a negative result occurs when the wrong test was ordered or there isn’t a genetic cause for that person’s symptoms. A “true negative” is when there is a known genetic change in the family and the person tested did not inherit it. If your test results are negative and there is no known genetic change in your family, a negative test result may not give you a definite answer. This is because you might not have been tested for the genetic change that runs in your family.
- Uncertain – a variant of unknown or uncertain significance means there isn’t enough information about that genetic change to determine whether it is benign (normal) or pathogenic (disease causing).
1. Genetic Testing | CDC. Sep 23, 2022 [accessed on Feb 23, 2022]
2. Genetic Testing: MedlinePlus. National Library of Medicine. Jun 11, 2021 [accessed on Feb 23, 2022]
3. What is genetic testing?: MedlinePlus Genetics [accessed on Feb 23, 2022]
4. Genetic Testing FAQ. Genome.gov [accessed on Feb 23, 2022]
5. Genetic testing and your cancer risk: MedlinePlus Medical Encyclopedia [accessed on Feb 23, 2022]

Normal reference ranges can vary depending on the laboratory and the method used for testing. You must use the range supplied by the laboratory that performed your test to evaluate whether your results are "within normal limits."

Additional Materials (21)

Genetic testing

Genetic testing fact sheet

Image by genome.gov

Genetic testing

Genetic testing existed before the Human Genome Project and the list of diseases that we can already screen for may be longer than you think.

Image by TheVisualMD

Genes and Genetic Defects

Genetic testing isn't new. In the 1960s, doctors were able to test newborn babies for certain rare single-gene disorders, such as phenylketonuria (PKU), a rare metabolic disease that causes mental retardation. (PKU can be prevented with a special diet if it's detected early, which was why it was critical to test newborns.)

Image by TheVisualMD

Mapping Your Future: Screening for Disease Risk

Image by TheVisualMD

Each person with Down syndrome has different talents and the ability to thrive.

Down syndrome is a lifelong condition. Services early in life will often help babies and children with Down syndrome to improve their physical and intellectual abilities. Most of these services focus on helping children with Down syndrome develop to their full potential. These services include speech, occupational, and physical therapy, and they are typically offered through early intervention programs in each state. Children with Down syndrome may also need extra help or attention in school, although many children are included in regular classes.

Image by CDC

genetic analysis

Biotechnology - DNA analysis and treatment

Image by OpenClipart-Vectors/Pixabay

Family history (medicine)

An extended family in Spain

Image by Ojedamd

Biotechnology

This diagram shows the basic method used for extraction of DNA.

Image by CNX Openstax

Genetic Counselor at Sanford Health Explains the Benefits to Genetic Testing

Video by Sanford Health/YouTube

What Is A Genetic Counselor & The Importance of Genetic Counselling | Ambry Genetics

Video by Ambry Genetics/YouTube

How Does The Genetic Testing Process Work? Genetic Testing FAQ | Ambry Genetics

Video by Ambry Genetics/YouTube

Should You Get Genetic Testing During Your Pregnancy?

Video by St. Louis Children's Hospital/YouTube

Debating Embryonic Genetic Testing -- The Doctors

Video by The Doctors/YouTube

Genetic Testing for Cancer — AMITA Health | NBC Chicago Ask the Doc

Video by AMITA Health/YouTube

MedGenome BRCA - Breast Cancer Genetic Testing

Video by MedGenome/YouTube

Genetic Testing for Hereditary Forms of Kidney Cancer - Brian Shuch, MD

Video by UCLA Health/YouTube

Do I need Genetic Testing for Ichthyosis?

Video by foundation for ichthyosis/YouTube

What Is Genetic Testing? Understanding the Process and Its Results

Video by uvahealth/YouTube

How to Understand Your Genetic Testing Results

Video by Breast Cancer Answers®/YouTube

Genetic Testing 101 for People with Rare Diseases

Video by National Organization for Rare Disorders (NORD)/YouTube

What's the difference between genetic and genomic testing?

Video by Cancer Treatment Centers of America - CTCA/YouTube

Genetic testing

genome.gov

Genetic testing

TheVisualMD

Genes and Genetic Defects

TheVisualMD

Mapping Your Future: Screening for Disease Risk

TheVisualMD

Each person with Down syndrome has different talents and the ability to thrive.

CDC

genetic analysis

OpenClipart-Vectors/Pixabay

Family history (medicine)

Ojedamd

Biotechnology

CNX Openstax

1:57

Genetic Counselor at Sanford Health Explains the Benefits to Genetic Testing

Sanford Health/YouTube

1:06

What Is A Genetic Counselor & The Importance of Genetic Counselling | Ambry Genetics

Ambry Genetics/YouTube

0:45

How Does The Genetic Testing Process Work? Genetic Testing FAQ | Ambry Genetics

Ambry Genetics/YouTube

3:04

Should You Get Genetic Testing During Your Pregnancy?

St. Louis Children's Hospital/YouTube

4:40

Debating Embryonic Genetic Testing -- The Doctors

The Doctors/YouTube

1:31

Genetic Testing for Cancer — AMITA Health | NBC Chicago Ask the Doc

AMITA Health/YouTube

2:10

MedGenome BRCA - Breast Cancer Genetic Testing

MedGenome/YouTube

1:37

Genetic Testing for Hereditary Forms of Kidney Cancer - Brian Shuch, MD

UCLA Health/YouTube

1:43

Do I need Genetic Testing for Ichthyosis?

foundation for ichthyosis/YouTube

2:01

What Is Genetic Testing? Understanding the Process and Its Results

uvahealth/YouTube

3:58

How to Understand Your Genetic Testing Results

Breast Cancer Answers®/YouTube

1:00:31

Genetic Testing 101 for People with Rare Diseases

National Organization for Rare Disorders (NORD)/YouTube

2:05

What's the difference between genetic and genomic testing?

Cancer Treatment Centers of America - CTCA/YouTube

Treatment

Roaccutane® (isotretinoin) - oral retinoids

Image by Jpogi e Andre Teixeira Lima (upload Commons)

Roaccutane® (isotretinoin) - oral retinoids

Roaccutane (isotretinoin) is used to treat severe cases of acne by reducing the bacteria in and the sebum produced by skin glands and opening clogged pores.

Image by Jpogi e Andre Teixeira Lima (upload Commons)

How Is Ichthyosis Treated?

There is currently no cure for ichthyosis. The goals of treatment include reducing the redness of the skin, thickness of the scales, and itching. Treatments can include:

Hydrating the skin with creams, lotions, or ointments to help trap moisture in the skin and relieve dryness and scaling. This works best if the topical agents are applied when the skin is moist.
Taking long baths to soften and release scales.
Using an oral or topical retinoid, a type of medication that can decrease scaling.
Using prescription creams or ointments that may contain retinoids or other medications.

Depending on the type and severity of the disease, doctors may recommend additional treatment with “keratolytic” topical agents, which can help to loosen scales. However, these can be irritating for some people and have potential side effects if used in large amounts. Talk to your doctor before using any treatment option.

Source: National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)

Additional Materials (1)

Hope for newborn with Ichthyosis | Baby Carter

Video by KTNV Channel 13 Las Vegas/YouTube

4:43

Hope for newborn with Ichthyosis | Baby Carter

KTNV Channel 13 Las Vegas/YouTube

Who Treats It?

Skin cancer check

Image by NavyMedicine - Deidre Smith, Naval Hospital

Skin cancer check

Elizabeth Anderson, a physician assistant at Naval Hospital Jacksonville’s Dermatology Clinic, uses a lighted scope to check a patient’s skin. “Skin cancer rates are high in Florida, and it’s important to self-check monthly,” Anderson said. Skin cancer is the most common cancer in the U.S. To reduce risk, protect your skin from UV rays from the sun, tanning booths, and sunlamps.

Image by NavyMedicine - Deidre Smith, Naval Hospital

Who Treats Ichthyosis?

You may see one or more of the following specialists:

Dermatologists, who specialize in conditions affecting the skin, hair, and nails.
Allergists/immunologists, who specialize in treating allergies and diseases and health issues brought on by problems with the immune system.
Audiologists, who diagnoses and treats hearing and balance problems.
Clinical geneticists, who diagnose children and adults with genetic disorders.
Ear, nose, and throat doctors, who help to manage hearing and ear problems.
Genetic counselors, who counsel and educate people on their genetic health.
Nurse educators, who specialize in helping people to understand their overall condition and to set up their treatment plans.
Ophthalmologists, who treat disorders and diseases of the eye.
Neurologists, who treat disorders of the brain, spinal cord, and nerves.
Pediatricians, who diagnose and treat children.
Primary care physicians, who diagnose and treat adults.

Source: National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)

Additional Materials (4)

Illustration of a doctor examining a rash on a woman’s arm

Illustration of a doctor examining a rash on a woman’s arm. You’ve probably had a rash at some point or another, whether from poison ivy or the chickenpox or something more unusual. Why does your skin break out in red blotches like that? More important, is there anything you can do about it?

Image by NIH News in Health

Dermatology

Dermatology

Image by Noun Project

Dermatologist uses dermatascope and magnifying loops during a skin exam

Lt. Cmdr. Stephen Mannino examines a Sailor using a dermatascope and magnifying loops during a skin cancer screening at Naval Special Warfare medical clinic at Naval Amphibious Base, Coronado. More than 70 Sailors in special warfare commands were screened for skin cancer during the event. (U.S. Navy photo by Mass Communication Specialist 2nd Class Dominique M. Lasco/Released)

Image by U.S. Navy photo by Mass Communication Specialist 2nd Class Dominique M. Lasco/Wikimedia

Dermatologist infographic

Reasons to visit dermatologist

Image by Impala6868

Illustration of a doctor examining a rash on a woman’s arm

NIH News in Health

Dermatology

Noun Project

Dermatologist uses dermatascope and magnifying loops during a skin exam

U.S. Navy photo by Mass Communication Specialist 2nd Class Dominique M. Lasco/Wikimedia

Dermatologist infographic

Impala6868

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Harlequin Ichthyosis

Harlequin ichthyosis is a severe genetic disorder that mainly affects the skin. Infants with this condition are born with very hard, thick skin covering most of their bodies. Explore symptoms, causes, and genetics of this rare disorder.

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