Compound Heterozygous FKTN Variants in a Patient with Dilated Cardiomyopathy Led to an Aberrant alpha-Dystroglycan Pattern

Fukutin encoded by FKTN is a ribitol 5-phosphate transferase involved in glycosylation of alpha-dystroglycan. It is known that mutations in FKTN affect the glycosylation of alpha-dystroglycan, leading to a dystroglycanopathy. Dystroglycanopathies are a group of syndromes with a broad clinical spectrum including dilated cardiomyopathy and muscular dystrophy. In this study, we reported the case of a patient with muscular dystrophy, early onset dilated cardiomyopathy, and elevated creatine kinase levels who was a carrier of the compound heterozygous variants p.Ser299Arg and p.Asn442Ser in FKTN. Our work showed that compound heterozygous mutations in FKTN lead to a loss of fully glycosylated alpha-dystroglycan and result in cardiomyopathy and end-stage heart failure at a young age.