Congenital glaucoma: CYP1B1 mutations in Israeli Bedouin kindreds

To investigate CYP1B1 gene mutations in Arab-Bedouin Israeli patients with primary congenital glaucoma (PCG).

Testing linkage to candidate genes using adjacent polymorphic markers and sequencing of genomic DNA samples by standard methods.

In 9 of 11 unrelated affected Israeli Bedouin families, PCG was associated with homozygosity of 3 different CYP1B1 mutations. As in Saudi Arabian families, the 3987G>A CYP1B1 substitution accounted for approximately 50% of cases. A novel CYP1B1 mutation, 8405G>A, was found in 2 unrelated families. In 2 consanguineous families, there was no evidence of homozygosity or mutations in CYP1B1.

CYP1B1 mutations account for the majority of cases of PCG in the Israeli Bedouin population. The most frequently found CYP1B1 mutation (3987G>A) in our study is also the commonest CYP1B1 mutation in the Saudi Arabian population, in line with the common genetic background of both populations. The absence of homozygosity in the CYP1B1 locus in the affected individuals in 2 consanguineous inbred families, suggests that other genes take part in the causation of congenital glaucomas. This is the first study describing the genetic basis of PCG among Israeli Arab-Bedouin individuals, in whom the frequency of the disease is the highest in the world. Further similar studies based on new diagnosed patients are needed to possibly prevent, screen, and treat (antenatal and postnatal) this sight-devastating childhood disease.