Glutathione synthetase deficiency is a disorder that prevents the production of an important molecule called glutathione. Glutathione helps prevent damage to cells by neutralizing harmful molecules generated during energy production. Glutathione also plays a role in processing medications and cancer-causing compounds (carcinogens), and building DNA, proteins, and other important cellular components.

Glutathione synthetase deficiency can be classified into three types: mild, moderate, and severe. Mild glutathione synthetase deficiency usually results in the destruction of red blood cells (hemolytic anemia). In addition, affected individuals may release large amounts of a compound called 5-oxoproline in their urine (5-oxoprolinuria). This compound builds up when glutathione is not processed correctly in cells.

Individuals with moderate glutathione synthetase deficiency may experience symptoms beginning shortly after birth including hemolytic anemia, 5-oxoprolinuria, and elevated acidity in the blood and tissues (metabolic acidosis).

In addition to the features present in moderate glutathione synthetase deficiency, individuals affected by the severe form of this disorder may experience neurological symptoms. These problems may include seizures; a generalized slowing down of physical reactions, movements, and speech (psychomotor retardation); intellectual disability; and a loss of coordination (ataxia). Some people with severe glutathione synthetase deficiency also develop recurrent bacterial infections.

• 25% chance to inherit both changed copies of the GSS gene, meaning the child will have glutathione synthetase deficiency
• 50% chance to inherit one changed copy of the GSS gene, meaning the child will be a carrier of glutathione synthetase deficiency like both parents
• 25% chance to inherit both working copies of the GSS gene, meaning the child will not have glutathione synthetase deficiency and will not be a carrier of the deficiency

Newborn screening for Glutathione synthetase deficiency requires collecting a small amount of blood from your baby’s heel. Screening measures how much 5-oxoproline is in your baby’s blood. Babies with high levels of 5-oxoproline might have glutathione synthetase deficiency.

What Happens After an Out-of-Range Screening Result?

If your baby’s blood spot screening result for Glutathione synthetase deficiency is out-of-range, your baby’s health care provider will contact you. Together, you will discuss next steps and follow-up plans.

An out-of-range screening result does not mean that your baby definitely has the condition. It does mean that your baby needs more follow-up testing.

Your baby may need the following tests after an out-of-range screening result:

• Blood and/or urine tests
• Genetic testing using a blood sample

You should complete any recommended follow-up testing as soon as possible. Babies with this condition can have serious health problems soon after birth if they are not diagnosed and treated quickly.

False-positive newborn screening results for this condition can happen.

Newborn screening helps babies lead healthier lives. If your baby has an out-of-range result, follow up with your health care provider quickly. It is important to follow their instructions. Your baby may need to get treatment right away, even if they are not showing signs or symptoms. In some cases, your baby’s health care provider may decide it is best to watch (monitor) your baby to decide next steps. Careful monitoring and early treatment will help your baby stay as healthy as possible.