Waardenburg syndrome (WS): the analysis of a single family with a WS1 mutation showing linkage to RFLP markers on human chromosome 2q.
 Waardenburg syndrome type I (WS1; MIM 19350) is caused by a pleiotropic, autosomal dominant mutation with variable penetrance and expressivity.
 Of individuals with this mutation, 20%-25% are hearing impaired.
 A multilocus linkage analysis of RFLP data from a single WS1 family with 11 affected individuals indicates that the WS1 mutation in this family is linked to the following four marker loci located on the long arm of chromosome 2: ALPP (alkaline phosphatase, placental), FN1 (fibronectin 1), D2S3 (a unique-copy DNA segment), and COL6A3 (collagen VI, alpha 3).
 For the RFLP marker loci, a multilocus linkage analysis using MLINK produced a peak lod (Z) of 3.23 for the following linkage relationships and recombination fractions (theta i): (ALPP----.000----FN1)----.122----D2S3----.267----CO L6A3.
 A similar analysis produced a Z of 6.67 for the following linkage relationships and theta i values among the markers and WS1: (FN1----.000----WS1----.000----ALPP)----.123----D2S 3----.246----COL6A3.
 The data confirm the conclusion of Foy et al.
 that at least some WS1 mutations map to chromosome 2q.
