ALBINISMO OCULARE CON SORDITA' NEUROSENSORIALE TARDIVA
In a large Afrikaner kindred, Winship et al. (1984) observed 7 males in 4 sibships in 3 generations with the combination of typical ocular albinism and sensorineural deafness of late onset. Typicality of the ocular albinism was supported by numerous macromelanosomes demonstrated on skin biopsy of both affected males and carriers. Deafness was moderately severe by late middle age. The pedigree pattern was consistent with X-linked recessive inheritance. In the same large South African family, Winship et al. (1993) found tight linkage to the DXS452 locus at Xp22.3 using 25 informative meioses, with a maximum lod score of 7.1 at a recombination fraction of 0.0. Since OA1 (300500) has been mapped to Xp22.3-p22.2, Winship et al. (1993) suggested that OA1 and OASD may be allelic variants or that they may be due to contiguous gene defects.