Abstract
Abstract: :
Purpose:Primary congenital glaucoma an important world wide cause of blindness in children. Mutations in the cytochrome P450 protein, CYP1B1, has been found in individuals from a variety of ethnic backgrounds including Saudi Arabia, Turkey, Japan and Slovakia (gypsies). The purpose of this study was to characterize mutations in CYP1B1 in patients from countries with diverse ethnic backgrounds such as Brazil and the United States. Methods:: Nine Brazilian families and eight American families with congenital glaucoma were used for this study. Affected individuals demonstrated an onset of bilateral glaucoma during the first months of life. In each family the inheritance of the disease was consistent with an autosomal recessive pattern. Oligonucleotides flanking the translated exons of the CYP1B1 gene were used to amplify genomic DNA purified from each affected individual and relevant family members. The amplification products were sequenced using BIGDYE chemistry and an ABI 310 automated sequencer. Microsatellite repeat markers located on the BAC containing the CYP1B1 gene were identified using BLAST (http://ncbi.nlm.nih.gov). Results:: Mutations were found in one American family and two Brazilian families. In affected members from the two Brazilian families four different mutations were found including 1546dup10, G1691del, G1505A, and a deletion of the entire gene. The American mutations included the 1546dup10 and 4611del9. Haplotype analysis performed using SNPs within the CYP1B1 gene as well as microsatellite repeat markers located in close proximity to the CYP1B1 gene demonstrated a common haplotype between the American and Brazilian patients carrying the 1546dup10 mutation. Conclusion:The results of this study have identified five different mutations in American and Brazilian patients affected with primary congenital glaucoma. Two of the mutations found in the Brazilian families (G1691del and G1505A) have only been found in Hispanic families. One of the mutations found in the American family (4611del9) has previously been found in one Saudi Arabian family. The 1546dup10 mutation was identified in both a Brazilian patient and an American patient. This mutation has been previously described in patients from Turkey, the United States, the United Kingdom and Germany. The common haplotype found on the chromosome carrying the 1546dup10 mutation in the American and Brazilian patients in our study suggests that this mutation originated from a single ancestral event.
Keywords: 335 candidate gene analysis • 420 genetics