Whole-Body Muscle MRI Characteristics of LAMA2 Gene Mutation Congenital Muscular Dystrophy Children

Merosin-deficient or LAMA2-related congenital muscular dystrophy (CMD) belongs to a group of muscle diseases with an overlapping diagnostic spectrum. MRI plays an important role in the diagnosis and disease-tracking of muscle diseases. Whole-body MRI is ideal for describing patterns of muscle involvement. Our purpose is to analyze the pattern of muscle involvement in merosin-deficient CMD children employing whole-body muscle MRI. Ten children with merosin-deficient CMD underwent whole-body muscle MRI. We used a control group of other hereditary muscle diseases, which included 13 children. Overall, 37 muscles were graded for fatty infiltration using Mercuri scale modified by Fischer et al 2008. The results showed a fairly consistent pattern of muscle fatty infiltration in index group, which differed from that in control group. There was a highly statistically significant difference between the two groups in regard to the fatty infiltration of the neck, serratus anterior, rotator cuff, deltoid, forearm, gluteus maximus, gluteus medius, gastrocnemius and soleus muscles. Additionally, results showed relative sparing of the brachialis, biceps brachii, gracilis, sartorius, semitendinosus and extensor muscles of the ankle in index group. There is evidence to suggest that whole-body muscle MRI can become a useful contributor to the differential diagnosis of merosin deficient CMD. Study Highlights Whole-body muscle MRI is a useful contributor to the differential diagnosis of merosin-deficient (LAMA2-related) congenital muscular dystrophy. The study demonstrated the presence of a fairly characteristic pattern of whole-body muscle MRI in children with merosin-deficient CMD in terms of sensitivity and specificity. The study may be considered as a preliminary step of arriving at an MRI classification system for children with merosin-deficient CMD.