Myotonic dystrophy is primarily related to mutations in which gene?

Myotonic dystrophy, particularly myotonic dystrophy type 1 (DM1), is primarily associated with mutations in the DMPK gene. This gene, which stands for Dystrophia Myotonica Protein Kinase, is located on chromosome 19 and is responsible for encoding a protein involved in muscle function and regulation of other cellular activities.

In myotonic dystrophy, a specific type of mutation called a repeat expansion occurs, where a repeated sequence of nucleotides (specifically, CTG repeats) becomes abnormally elongated in the DMPK gene. This abnormal expansion disrupts normal gene function, leading to the symptoms associated with the disease, such as muscle weakness, myotonia (difficulty relaxing muscles), and various systemic manifestations.

The other genes listed, while involved in other types of diseases or conditions, are not primarily associated with myotonic dystrophy. For instance, the MYH7 gene is primarily related to familial hypertrophic cardiomyopathy, the TP53 gene is a tumor suppressor gene involved in various cancers, and the SYNE1 gene is linked to muscular dystrophies but not specifically myotonic dystrophy. Therefore, the mutation in the DMPK gene is the definitive genetic alteration