| An autosomal dominant subtype of Waardenburg syndrome (WS) with characteristics of varying degrees of deafness and pigmentation anomalies of eyes, hair and skin but without dystopia canthorum. The disease is genetically very heterogeneous, mutations have been found in MITF (3p14-p13; subtype designated as WS2A), SNAI2 (8q11.21; WS2D), and SOX10 (22q13.1; WS2E) genes. Furthermore WS2 loci have been mapped to chromosome 1p21-p13.3 (subtype designated as WS2B) and to chromosome 8p23 (designated as WS2C). Digenic inheritance of MITF mutation in combination a TYR mutation (and/or the TYRR402Q hypomorphic allele) has been reported in two families with WS2 and ocular albinism. In the majority of cases, WS2 is transmitted as an autosomal dominant disorder with a large variable inter and intrafamilial expressivity. Some affected patients present with a de novo mutation. |
