GENETIC-HETEROGENEITY IN HISPANIC FAMILIES WITH AUTOSOMAL-DOMINANT JUVENILE GLAUCOMA

A gene for autosomal dominant, juvenile-onset, primary open angle glau coma (GLCIA) has been previously mapped to Iq2I-3I in several Caucasia n pedigrees. We studied two Hispanic families with this disease to det ermine if their disease genes also map to this region. Individuals wer e considered as being affected if they had IOP > 30 mmHg (without trea tment) and glaucomatous optic nerve damage or visual field defects. Pe rsons older than 40 years with intraocular pressures less than or equa l to 2I mmHg and no evidence of optic nerve damage or visual field los s were scored as unaffected. Individuals not falling into these two ca tegories were considered unknown. Genomic DNA was extracted from blood samples and subjected to PCR-based microsatellite marker analysis. Co mputer-based linkage analysis was used to determine if the disease gen e mapped to chromosome Iq2I-3I. In the family from the Canary Islands, the disease gene was linked to the chromosome Iq2I-3I region previous ly identified by other researchers. Markers DIS2I2 and DIS2I8 produced maximum lod scores of 3.38 and 2.99, respectively. In the family from the Balearic Islands, the disease gene was excluded from this region by genetic linkage analysis. Haplotype analysis also excluded the dise ase gene from chromosome Iq2I-3I. Our Hispanic families showed genetic heterogeneity with respect to autosomal dominant, juvenile-onset, pri mary open angle glaucoma.