Contribution of CYP1B1 mutations and founder effect to primary congenital glaucoma in Mexico.

PURPOSE: The frequency of primary congenital glaucoma (PCG)-causing CYP1B1 mutations varies importantly among distinct populations, ranging from 20% in Indonesians and Japanese to about 100% among the Saudi Arabians and Slovakian Gypsies. Thus, the molecular characterization of large groups of PCG from different ethnic backgrounds is important to establish the actual CYP1B1 contribution in specific populations. In this work, the molecular analysis of the CYP1B1 gene in a group of Mexican PCG patients is reported. MATERIAL AND METHODS: Thirty unrelated Mexican patients fulfilling the clinical criteria for PCG were included. Two cases were familial and with proven consanguinity, originating from distinct regions of the country. Polymerase chain reaction amplification and direct automated sequencing of the CYP1B1 coding region was performed in each participating subject. RESULTS: An identical pathogenic CYP1B1 mutation was demonstrated in 2 unrelated PCG subjects. The mutation consisted of a homozygous G to A transition at nucleotide position 1505 in exon 3, which predicted a substitution of glutamic acid for lysine at residue 387 of the protein (E387K). In the remaining 28 PCG subjects, no deleterious mutations were identified. Both subjects with the E387K mutation shared a same haplotype for 5 CYP1B1 intragenic single nucleotide polymorphisms, indicating a common origin of the allele. CONCLUSIONS: Mexican patients with PCG are rarely (less than 10%) due to CYP1B1 mutations. Available data indicate that most of the non-Brazilian Latin American PCG patients investigated to date are not due to CYP1B1 defects. Populations with low incidence of CYP1B1 mutations are appropriate candidates for the identification of novel PCG-causing genes.

Comparison of the stability, efficacy, and adverse effect profile of the innovator 0.005% latanoprost ophthalmic solution and a novel cyclodextrin-containing formulation.

Recently, a new latanoprost ophthalmic solution containing cyclodextrins was developed. The purpose of the present work was to compare the stability, clinical efficacy, and adverse effect profile of this formulation with the innovator product. The innovator formulation was stable at 4 degrees C but exhibited degradation at higher temperatures, whereas the cyclodextrin-containing formulation was stable at temperatures up to 40 degrees C. Formulations were assayed in a randomized double-blind clinical study in patients with primary open-angle glaucoma and/or ocular hypertension. Both latanoprost ophthalmic solutions produced comparable reduction of intraocular pressure. Conjunctival hyperemia was observed in 11.9% and 11.3% of the patients treated with the innovator and the cyclodextrin-containing formulations, respectively. There were no significant differences between the 2 ophthalmic solutions in efficacy or in the measured adverse effect. It is concluded that these 2 latanoprost ophthalmic solutions yield comparable efficacy and adverse effect outcomes. The cyclodextrin-containing formulation, however, has an improved stability.