The study included 82 individuals. Twenty-two were sporadic unrelated patients with Primary Congenital Glaucoma (PCG), and 60 were the members of 10 multiplex families. They were enrolled into two groups; GI:10 multiplex families; GII:32 unrelated patients with PCG (22 sporadic plus 10 probands of the multiplex families). The following were carried out for all the individuals: (1) detailed history; (2) ophthalmologic examination for diagnosis of PCG; (3) clinical examination to exclude any other disease; (4) HLA antigen typing using 30 antigens, 9 for A locus, 15 for B locus, and 6 for DR locus. Genetic and statistical analysis revealed the following: (1) significant association between HLA-B8 and PCG; (2) family studies revealed a susceptibility gene, probably recessive, predisposing to PCG; (3) this gene is linked to HLA, with strong linkage disequilibrium with B8.