Myotonic Dystrophy 1 (DMPK) Genetic Testing (Repeat Expansion)

Use: Type 1 myotonic dystrophy results from a mutation in the DMPK gene known as a trinucleotide repeat expansion. This mutation increases in the size of the repeated CTG segment in the DMPK gene. People with type 1 myotonic dystrophy have from 50 to 5,000 CTG repeats in most cells. The number of repeats may be even greater in certain types of cells, such as muscle cells.

Limitations: Maximum reportable sizing: 150 repeats.

This test was developed and its performance characteristics determined by LabCorp. It has not been cleared or approved by the Food and Drug Administration.

Methodology: Repeat-Primed PCR (QP-PCR)