Craniofacial abnormalities commonly seen in patients with PPS include hypertelorism, ear malformations, micrognathia, round face and broad neck, and cleft lip and palate.[1]
The pattern of inheritance of Peters-plus is autosomal recessive, where both parents are heterozygous they can produce a child with the syndrome. The B3GALTL[3] (now called B3GLCT) gene codes for the enzyme beta 3-glucosyltransferase (B3Glc-T).[4]
The beta 3-glucosyltransferase enzyme is responsible for glycosylation, the attachment of sugars to proteins, which through this modification allows for performance of a wider variety of functions. The mutations of the B3GLCT gene in affected individuals results in loss-of-function of the beta 3-glucosyltransferase enzyme. The result of this disruption in glycosylation is a change to the secondary structure of the mRNA. These mutations of the B3GLCT gene lead to the production of an abnormally short, nonfunctional version of the beta 3-glucosyltransferase (B3Glc-T) enzyme, which disrupts glycosylation.[5]
The phenotypic effects of the B3GLCT mutations result in a triad of well known phenotypes; Peters anomaly (also classified as anterior segment defects, a defect in the anterior cornea), short stature, brachydactyly, in addition to several other less frequently observed phenotypes.[6] A study of 55 patients with Peters-plus-related phenotypes, but lacking the most common combination (Peters anomaly, short stature, and brachydactyly), revealed none of those cases displayed mutation in the B3GLCT gene. Thus PPS-like signs and symptoms, when they occur independently of each other, provide strong evidence that the B3GLCT gene mutation is in fact responsible for actual cases Peters-plus syndrome.[7]
History
Krause–van Schooneveld–Kivlin syndrome is listed as a "rare disease" by the Office of Rare Diseases (ORD) of the National Institutes of Health (NIH).[8]
It was characterized in 1984 by van Schooneveld.[9]
