Last modified: 2018-09-09
Abstract
Introduction: Hereditary muscular dystrophies contribute to significant neurological morbidities in childrenall over the world.
Methods: The etiopathological profile of children 1 month to 18 years diagnosed with muscular dystrophy in a North Indian tertiary care center between May 2013 and April 2018 were analyzed. Sensitivity and specificity of a clinical diagnostic algorithm for congenital muscular dystrophy(CMD) and limb girdle muscular dystrophy(LGMD) in children based on physical examination findings was also determined.Muscle biopsy findings were considered as gold standard (in Dystrophin gene deletion negative children). Genetic testing with next generation sequencing (NGS) was performed, wherever feasible, especially in children with unclassified muscular dystrophy in biopsy.
Results: Out of 961 children with hereditary muscular weakness (898 boys, 93%, 6.2+/- 2.3 years), 209 children (21%; 149 boys, 8.1+/- 1.7 years) were Dystrophin gene deletion negative and required muscle biopsy. NGS was performed in 23(2%) children, including 14 children with Unclassified Muscular dystrophy.
Dystrophinopathy (88%), LGMD(6%),CMD (3%) and Facio-scapulo-humeral dystrophy (1%)were predominant subgroups. Sarcoglycanopathy (40%), Calpainopathy (21%), Dysferlinopathy (13%) and Caveolinopathy (12%) were identified as predominant subgroups of LGMD, with onset >5 years. Merosinopathy (36%), Collagen type VI associated CMD(27%) and Dystroglycanopathy (19%) were predominant subgroups of CMD, with onset <2 years.
The diagnostic algorithm had good sensitivity and specificity of 80%-90% for Sarcoglycanopathy, Calpainopathy, Merosinopathy and Collagen type VI associated CMD.
Conclusion: Sarcoglycanopathy and Merosinopathy are most common type of LGMD and CMD respectively.In resource constrained set up, a concise diagnostic algorithm may provide the etiological diagnosis in a significant proportion of cases.