LOCALIZATION OF THE SCHWARTZ-JAMPEL SYNDROME (SJS) LOCUS TO CHROMOSOME 1P34-P36.1 BY HOMOZYGOSITY MAPPING

Schwartz-Jampel syndrome (SJS, MIM 255800), also known as chondrodystr ophic myotonia, is a rare autosomal recessive disorder characterized b y generalized myotonia, skeletal abnormalities and facial dysmorphism. Using homozygosity mapping, we localized the SJS locus to chromosome 1p34-p36.1 in a 8 cM interval flanked by markers D1S199 and D1S234. Fa milies of different ethnic backgrounds (Tunisia and South Africa) show ed genetic linkage to the same locus. Moreover, one Algerian family al so demonstrated evidence of genetic linkage to 1p34-p36.1. Taken altog ether, our results suggest genetic homogeneity, at least in the group of families analyzed,