Purpose. Primary congenital glaucoma (PCG) is an autosomal recessive disorder that has been linked to CYP1B1 mutations. This study was conducted to explore the role of FOXC1, which is involved in anterior segment dysgenesis, in PCG. methods. An earlier screening for CYP1B1 in a clinically well-characterized PCG cohort (n = 301) revealed cases that were either homozygous (n = 73), compound heterozygous (n = 18), or heterozygous (n = 41) for the mutant allele, whereas the remaining (n = 169) did not harbor any mutation. Hence, FOXC1 was screened in 210 PCG cases who were either heterozygous (n = 41) or did not harbor any CYP1B1 mutation (n = 169), along with ethnically matched normal control subjects (n = 157) by resequencing the entire coding region. results. Two heterozygous missense (H128R and C135Y) and three frame shift mutations (g.1086delC, g.1155del9bp, and g.1947dup25bp) were observed in FOXC1 in 5 (2.38%) of 210 cases. The missense mutations had a de novo origin in two sporadic cases, whereas the FOXC1 deletions were seen in two cases that were also heterozygous for the CYP1B1 allele (R368H). The parents of the proband with g.1086delC were heterozygous for either the FOXC1 or CYP1B1 alleles. The unaffected mother of the proband with the g.1155del9bp was heterozygous for both the FOXC1 and CYP1B1 alleles; the father harbored only the FOXC1 allele. Familial segregation of the g.1947dup25bp could not be performed because of the unavailability of DNA from one parent. Except for the g.1155del9bp (0.95% normal chromosomes), all the other variations were absent in the control subjects. conclusions. The present study indicates a limited role of FOXC1 in PCG pathogenesis.

Primary congenital glaucoma (PCG) is an autosomal recessive disorder in children due to the abnormal development of the trabecular meshwork and the anterior chamber angle. With an onset at birth to early infancy, PCG is highly prevalent in inbred populations and consanguinity is strongly associated with the disease. Gene mapping of PCG-affected families has identified three chromosomal loci, GLC3A, GLC3B and GLC3C, of which, the CYP1B1 gene on GLC3A harbors mutations in PCG. The mutation spectra of CYP1B1 vary widely across different populations but are well structured based on geographic and haplotype backgrounds. Structural and functional studies on CYP1B1 have suggested its potential role in the development and onset of glaucomatous symptoms. A new locus (GLC3D) harboring the LTBP2 gene has been characterized in developmental glaucoma but its role in classical cases of PCG is yet to be understood. In this review, we provide insight into PCG pathogenesis and the potential role of CYP1B1 in the disease phenotype.

Purpose. To obtain a global perspective on the distribution and evolution of CYP1B1 mutations in primary congenital glaucoma (PCG) worldwide.

EMBO Press is an editorially independent publishing platform for the development of EMBO scientific publications.