Cosegregation of open-angle glaucoma and the nail-patella syndrome

PURPOSE: To evaluate two families ascertained only for the presence of glaucoma in which both nail patella syndrome and glaucoma occur in several generations and to determine whether the two diseases are genetically related. METHODS: Ophthalmologic examinations and orthopedic examinations were performed. DNA samples from family members were screened with a microsatellite repeat marker at: the argininosuccinate synthetase (ASS) locus at 9q34, and linkage analysis was performed, RESULTS: Sir: patients with open angle glaucoma were found among 13 patients with nail-patella syndrome in family UM:47. Seven patients with glaucoma were found among II patients with naif patella syndrome in family UM:65, In both families, all individuals with glaucoma also had nail-patella syndrome, Two-point linkage analysis resulted in a lod score of 2.98 at a recombination fraction of 0.00 for open-angle glaucoma and nail-patella syndrome, CONCLUSIONS: Linkage results presented here provide strong evidence that the orthopedic and nail anomalies in these two families result from the same nail-patella syndrome locus that has been previously linked to markers at 9q34. These data provide indirect evidence for a possible glaucoma locus at 9q34 and do not allow us to distinguish whether the glaucoma is the result of the nail-patella syndrome mutation or whether there is a separate locus responsible for glaucoma in these families, These studies suggest a need for ophthalmologic examination of individuals with nail patella syndrome.