LAMA2 and hyperinsulinemic hypoglycemia, familial, 4: The most common CMDs are Ulrich congenital muscular dystrophy (UCMD, OMIM 254090) due to the pathology of collagen VI (mutations are found in three genes) [4], secondary dystroglycanopathies associated with a violation of α-dystroglycan (16 candidate genes) [5] and CMD caused by a primary merosin deficiency (merosin-deficient congenital muscular dystrophy, MDC1A) due to mutation of the LAMA2 gene [6].