DMPKgenen

DMPK, or dystrophia myotonica protein kinase, is a gene that encodes a serine/threonine protein kinase. It is located on chromosome 19q13.32 and is expressed in skeletal and cardiac muscle, smooth muscle, brain, and other tissues. The DMPK protein participates in signaling pathways that regulate muscle contraction and cytoskeletal dynamics, and it is involved in phosphorylating substrates that influence muscle function and cell structure.

Normal function and regulation of DMPK contribute to muscle tone, intracellular signaling, and cytoskeletal organization. The precise spectrum of substrates and pathways varies, but the protein is broadly implicated in the regulation of contractile apparatus and muscle cell signaling.

Clinical significance of the DMPK gene is most prominently associated with myotonic dystrophy type 1 (DM1). DM1 is caused by an unstable expansion of CTG trinucleotide repeats in the 3' untranslated region of the DMPK gene. The resulting RNA transcript exhibits toxic effects that disrupt the regulation of alternative splicing in many transcripts, leading to the multi-systemic manifestations of the disease. Disease severity tends to correlate with repeat length, and congenital, childhood, and adult-onset forms are recognized. The condition shows anticipation, often with worsening symptoms in successive generations, particularly when inherited from the mother.

Genetic testing for DM1 typically involves measuring CTG repeat length in the DMPK gene. Beyond DM1, the broader biology of DMPK continues to be studied to understand its roles in muscle physiology and signaling more completely.