Peters plus syndrome is an inherited condition that is characterized by eye abnormalities, short stature, an opening in the lip (cleft lip) with or without an opening in the roof of the mouth (cleft palate), distinctive facial features, and intellectual disability.

The eye problems in Peters plus syndrome occur in an area at the front part of the eye known as the anterior segment. The anterior segment consists of structures including the lens, the colored part of the eye (iris), and the clear covering of the eye (cornea). An eye problem called Peters anomaly is the most common anterior segment abnormality seen in Peters plus syndrome. Peters anomaly involves abnormal development of the anterior segment, which results in a cornea that is cloudy (opaque) and causes blurred vision. Peters anomaly may also be associated with clouding of the lenses of the eyes (cataracts) or other lens abnormalities. Peters anomaly is usually bilateral, which means that it affects both eyes. The severity of corneal clouding and other eye problems can vary between individuals with Peters plus syndrome, even among members of the same family. Many people with Peters plus syndrome experience vision loss that worsens over time.

All people with Peters plus syndrome have short stature, which is evident before birth. The height of adult males with this condition ranges from 141 centimeters to 155 centimeters (4 feet, 7 inches to 5 feet, 1 inch), and the height of adult females ranges from 128 centimeters to 151 centimeters (4 feet, 2 inches to 4 feet, 11 inches). Individuals with Peters plus syndrome also have shortened upper limbs (rhizomelia) and shortened fingers and toes (brachydactyly).

The characteristic facial features of Peters plus syndrome include a prominent forehead; small, malformed ears; narrow eyes; a long area between the nose and mouth (philtrum); and a pronounced double curve of the upper lip (Cupid's bow). The neck may also be broad and webbed. A cleft lip with or without a cleft palate is present in about half of the people with this condition.

Developmental milestones, such as walking and speech, are delayed in most children with Peters plus syndrome. Most affected individuals also have intellectual disability that can range from mild to severe, although some have normal intelligence. The severity of physical features does not predict the level of intellectual disability.

Less common signs and symptoms of Peters plus syndrome include heart defects, structural brain abnormalities, hearing loss, and kidney or genital abnormalities.

Mutations in the B3GLCT gene cause Peters plus syndrome. The B3GLCT gene provides instructions for making an enzyme called beta 3-glucosyltransferase (B3Glc-T), which is involved in the complex process of adding sugar molecules to proteins (glycosylation). Glycosylation modifies proteins so they can perform a wider variety of functions. Most mutations in the B3GLCT gene lead to the production of an abnormally short, nonfunctional version of the B3Glc-T enzyme, which disrupts glycosylation. It is unclear how the loss of functional B3Glc-T enzyme leads to the signs and symptoms of Peters plus syndrome, but impaired glycosylation likely disrupts the function of many proteins, which may contribute to the variety of features.

Normal Function

The B3GLCT gene (formerly known as B3GALTL) provides instructions for making an enzyme called beta 3-glucosyltransferase (B3Glc-T), which is involved in the complex process of adding sugar molecules to proteins (glycosylation). Glycosylation modifies proteins so they can perform a wider variety of functions. The B3Glc-T enzyme is involved in a two-step glycosylation pathway that results in the formation of a sugar structure, made up of the sugars fucose and glucose, on a specific location of several different proteins. The B3Glc-T enzyme is responsible for the second step, which adds a glucose molecule to the fucose molecule already attached to the protein. The B3GLCT gene is normally turned on (active) in most cells of the body, which suggests that the B3Glc-T enzyme plays an important role across many cell types.

Health Conditions Related to Genetic Changes

Peters plus syndrome

At least 10 mutations that cause Peters plus syndrome have been identified in the B3GLCT gene. Peters plus syndrome is characterized by eye abnormalities, short stature, intellectual disability, and distinctive facial features. The most common B3GLCT gene mutation replaces the DNA building block (nucleotide) guanine with the nucleotide adenine near an area of the gene called exon 8 (written as 660+1G>A). This mutation disrupts how genetic information is pieced together to produce the B3Glc-T enzyme. The resulting enzyme is abnormally short and nonfunctional. It is unclear how the loss of functional B3Glc-T enzyme leads to the signs and symptoms of Peters plus syndrome, but impaired glycosylation likely disrupts the function of many proteins, which may contribute to the variety of features.

Other Names for This Gene

• B3GALTL
• B3Glc-T
• B3GLT_HUMAN
• B3GTL
• beta 1,3-galactosyltransferase-like
• beta-3-glycosyltransferase-like
• beta3Glc-T

Genomic Location

• Peters anomaly (abnormal structures in the front of the eye)
• Cloudy corneas
• Short stature
• Shortened limbs
• Developmental delay and/or intellectual disability
• Cleft lip and/or cleft palate

• Ophthalmologist
• Endocrinologist
• Developmental specialist
• Cardiologist
• Urologist
• Audiologist