The autosomal dominant disorder facioscapulohumeral muscular dystrophy (FSHD) is the last of the major progressive muscular dystrophies in which the gene had not been located. In linkage analysis on ten Dutch families with this disorder a lod score of 6.34 at a recombination fraction of 0.13 was obtained with the microsatellite marker Mfd 22 (D4S171). This maps the FSHD gene to chromosome 4. Only one family was uninformative for this marker. We found no evidence of genetic heterogeneity.