Diagnostic clues and manifesting carriers in fukutin-related protein (FKRP) limb-girdle muscular dystrophy

Mutations in the fukutin-related protein (FKRP) gene are a known cause of autosomal recessive limb-girdle muscular dystrophy. Clinically, patients resemble Becker's muscular dystrophy and generally present in the first two decades of life with a mild, progressive phenotype. Cardiac involvement is variable. Heterozygous carriers are usually clinically unaffected. We report a patient presenting later in life with life-threatening cardiac failure and we describe for the first time clinically manifesting carriers in the family.