Fktn, encoding fukutin, is a ribitol 5-phosphate transferase involved in the glycosylation of α-dystroglycan. This glycosylation process is crucial as α-dystroglycan plays important roles in maintaining muscle and cardiac structure and function. Mutations in Fktn can lead to dystroglycanopathy, affecting related biological pathways and contributing to the development of certain diseases [1,2].

In a study of a patient with muscular dystrophy, early-onset dilated cardiomyopathy, and elevated creatine kinase levels, compound heterozygous variants in Fktn led to a loss of fully glycosylated α-dystroglycan, resulting in cardiomyopathy and end-stage heart failure at a young age [1]. In another case, a child with elevated creatine kinase was found to have compound heterozygous variants of the Fktn gene, suggesting these variants underlay the disease and expanding the mutation spectrum of congenital muscular dystrophy [3]. Prenatal whole-exome sequencing in fetuses with congenital hydrocephalus detected compound variants in Fktn, demonstrating the genetic heterogeneity in such patients and expanding the gene mutational spectrum [4].

In conclusion, Fktn is essential for the proper glycosylation of α-dystroglycan, which is vital for muscle and cardiac function. Studies on Fktn-related mutations in patients have shown its significant contribution to diseases like dystroglycanopathy, congenital muscular dystrophy, and congenital hydrocephalus, highlighting the importance of understanding Fktn's function for disease diagnosis, genetic counseling, and potential treatment strategies.