Up till now four loci have been mapped (GLC3A, GLC3B, GLC3C, GLC3D) and two genes (CYP1B1, LTBP2) have been identified for primary congenital glaucoma.5,6 Samples from patients in families with linkage to GLC3A have mutations in CYP1B1.7,8 In highly inbred populations like Slovakian Gypsies, Iranians and Saudi Arabians; 80-100% prevalence of recessively inherited glaucoma is reported to be due to mutations in CYP1B1. In three Pakistani families three novel and one previously reported mutations have been identified in CYP1B1. The gene discussed is CYP1B1; the disease is glaucoma.