calpain and Chorea

The authors describe a family with six patients with muscular dystrophy with a variable course. One is a compound heterozygote for CAPN3 mutations (calpainopathy) and the others have a single CAPN3 mutation. Linkage analysis and sequencing revealed a XK gene mutation (McLeod syndrome). This illustrates the variable phenotype of XK mutations and suggests the possibility that CAPN3 heterozygotes may have their condition caused by nonallelic mutations in other unrelated genes.

Topics: Adolescent; Adult; Amino Acid Transport Systems, Neutral; Calpain; Chorea; Chromosome Mapping; Codon, Nonsense; DNA Mutational Analysis; Genetic Diseases, X-Linked; Genetic Predisposition to Disease; Genetic Testing; Genotype; Humans; Isoenzymes; Male; Muscle Fibers, Skeletal; Muscle Proteins; Muscle, Skeletal; Muscular Dystrophies, Limb-Girdle; Mutation; Pedigree; Phenotype; Syndrome