Muscle MRI findings in a one-year-old girl with merosin-deficient congenital muscular dystrophy type 1A due to LAMA2 mutation: A case report

The objective of the present study was to characterize the muscle magnetic resonance imaging (MRI) features of a 1-year-old girl with merosin-deficient congenital muscular dystrophy type 1A (MDC1A). Beginning as an infant, this patient exhibited severe hypotonia and proximal weakness, as well as delays in developmental milestones. Her serum creatine kinase levels at 3 months, 8 months and 1 year were 2,959, 1,621 and 1,659 U/l, respectively. Brain MRI indicated symmetric, mild T1WI low, mild T2WI and FLAIR high radial patterns in the white matter of the Cornu posterius of the ventricular lateral. Gene sequencing demonstrated a heterozygous frame-shift mutation in the LAMA2 gene, consisting of an AG deletion at nucleotides 2049–2050 (LAMA2 c.2049_2050delAG). Lower limb muscle MRI presented obvious fatty infiltration of the muscles and muscle atrophy during the early stage of the disease. The gluteus maximus, erector spinae, vastus intermedius, vastus lateralis, adductor magnus, soleus and gastrocnemius muscles were involved, whereas the piriformis, obturator internus, pectineus, adductor longus, adductor brevis and sartorius muscles presented mild or no involvement. Fatty infiltration of the erector spinae was observed during the early stage of the disease. As an additional tool in the differential diagnosis of muscle disorders, muscle MRI can delay the need for muscle biopsy.