A gene responsible for the pigment dispersion syndrome maps to chromosome 7q35-36

Purpose: To demonstrate the inheritance of the pigment dispersion syndrome in four families, and to determine the location of a gene responsible for this syndrome. Methods: Individuals from four pedigrees affected by the pigment dispersion syndrome and spouses were clinically examined for evidence of the pigment dispersion syndrome. DNA samples from patients and appropriate family members were used for a genome screen using microsatellite repeat markers distributed throughout the human genome. Genotypes were used for linkage analysis to identify markers segregating with the disease trait. Results: Twenty-eight patients showed clinical evidence of the pigment dispersion syndrome. Of these, fourteen also had elevated intraocular pressures requiring medical and/or surgical treatment. Significant linkage was observed between the disease phenotype and markers located on the telomere of the long arm of human chromosome 7 (7q35-q36). The maximum twopoint lod score (Zmax) was 5.45 at 9 = .05 for marker D7S550. Analysis of affected recombinant individuals demonstrated that the responsible gene is located in a 5cM interval between markers D7S2546 and D7S550. Conclusions: The pigment dispersion syndrome was found to be inherited as an autosomal dominant trait in four affected pedigrees. The gene responsible for the syndrome in these four families maps to the telomeric end of the long arm of chromosome 7 (7q35-q36). Locating a gene responsible for this condition is the first step toward the isolation of the gene itself. Characterization of the responsible gene will help elucidate the pathophysiology of this disease and potentially will lead to new methods of diagnosis and treatment.