Another interesting observation was the presence of
CYP1B1 mutations on specific haplotypes that was earlier observed in PCG.
16 We noted that C-C-G-G-T-A was the risk haplotype in cases of POAG and PACG with
CYP1B1 mutations. These results were consistent (even after reanalyzing the data set) based on a five-locus haplotype (i.e., C-G-G-T-A), similar to previous studies in different PCG populations worldwide.
16 32 33 35 37 On the other hand, the G-T-C-C-A haplotype that was largely associated with the unaffected controls and PCG cases without
CYP1B1 mutations
16 was similar in frequency in the POAG and PACG cases with
CYP1B1 mutations and the controls
(Tables 3 4) . In tune with our previous study on PCG,
16 most of the mutations observed in the POAG and PACG clustered on the C-G-G-T-A haplotype. The R368H mutation, which was the prevalent mutation in POAG and PACG in the present study, similar to PCG in India,
16 22 was found on the background of the C-G-G-T-A haplotype across all these phenotypes. Of interest, this mutation was also found on the same haplotype in Saudi Arabian
32 and Brazilian
37 PCG patients. The G61E mutation in POAG was also found on the C-G-G-T-A haplotype, similar to that observed among the PCG patients from Ecuador,
31 Saudi Arabia,
32 and Morocco.
33 The E229K mutation that was observed on the G-T-C-C-A haplotype among patients with PCG in India
16 and Germany
35 was also seen to harbor the same mutation in POAG and PACG cases. Another striking similarity was the presence of the Y81N mutation in a case of POAG on the G-T-C-C-A haplotype. This mutation was also found on the same haplotype among German patients with PCG.
35