Although primary congenital glaucoma (PCG) usually occurs sporadically, it may be inherited as an autosomal recessive trait. When no other family history of PCG exists, the chance of an affected parent having a child with PCG is approximately 2%. Four chromosomal loci for PCG have been identified: GLC3A on band 2p21, GLC3B on 1p36, GLC3C on 14q24.3, and GLC3D on 14q24.3. Mutations in CYP1B1 (at the GLC3A locus) have been shown to cause PCG. Populations in which consanguinity is common, especially those in which the carrier rate of the CYP1B1 gene is high, have higher incidences of PCG. Individuals who carry the CYP1B1 gene but who are nonpenetrant for PCG remain at higher risk for adult-onset glaucoma. LTBP2 mutations (at the GLC3D locus) cause a primary megalocornea with zonular weakness, forward displacement of the lens, and a secondary glaucoma that responds poorly to standard angle surgery. In this condition, the preferred treatment is lens removal.
Table 22-1 Classification of Childhood Glaucoma
Juvenile open-angle glaucoma is inherited as an autosomal dominant trait and has been linked to the GLC1A myocilin gene (MYOC), which is also responsible for some forms of adult open-angle glaucoma.
The genetic causes of many conditions associated with secondary childhood glaucoma have been identified; they are discussed in the chapters associated with their primary conditions.
Khan AO, Aldahmesh MA, Alkuraya FS. Congenital megalocornea with zonular weakness and childhood lens-related secondary glaucoma—a distinct phenotype caused by recessive LTBP2 mutations. Mol Vis. 2011;17:2570–2579.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.