A human clone corresponding to the gene encoding the alpha 1 subunit of the skeletal muscle dihydropyridine-sensitive calcium channel (CACNL1A3) has been isolated and partially sequenced. Oligonucleotides based on this sequence were used in a polymerase chain reaction to amplify specifically the human gene in human-rodent somatic cell hybrids, allowing the assignment of CACNL1A3 to chromosome 1. A polymorphic dinucleotide repeat also was identified in the human clone and using PCR was typed on a subset of the CEPH families. Multipoint linkage analysis places the CACNL1A3 gene between D1S52 and D1S70, on chromosome 1q31-q32.