INTRODUCTION : Muscle diseases of congenital origin have varied age and spectrum of manifestations. In some conditions the clinical phenotype predicts the genetic abnormality with accuracy ( e.g. Ullrich muscular dystrophy, CMD with central nervous system involvement). In rest of them we need to perform genetic evaluation for diagnosis, which if normal necessitates muscle biopsy.

METHOD : We reviewed children enrolled at our centre from 2015-2018 with clinical differential diagnosis of CM/CMD and for whom gene testing(neuromuscular panel) was done.

RESULTS : 28 patients were reviewed (male:female=1:1).The age of presentation was from birth to 15 years. Common presenting symptoms were motor delay and early contractures. 6 had neonatal onset (feeding and respiratory difficulties). Three died in early infantile period. Eleven had CM - Nemaline- 4 (NEB, ACTA1, CFL2) ; Central core -1 (RYR1) ;Centronuclear- 1 (SPEG) ;Congenital fibre type disproportion-1 (SEPN1), Myosin heavy chain-1(MYH7); Myofibrillar-1(DES) and Limb girdle myopathy-1(TNPO3 ).Two required tracheostomy ventilation( DES, RYR1 ). Ten had CMD- Four Ullrich CMD (COL6A3,COL6A2);Four Dystroglycanopathy (POMGNT1, POMGNT2, POMT2, B3GALNT2) and two Merosin deficient CMD (LAMA2).Two had limb girdle muscular dystrophy (TNPO3, PLEC). 3/28 had inconclusive genetic results. Antenatal counselling was offered for four of these families -three had normal pregnancies and one had affected fetus which was terminated.

CONCLUSION : 25/28 had genetic diagnosis consistent with phenotype.Thus, genetic evaluation in CM/CMD helps in accurate diagnosis,avoiding invasive investigations(muscle biopsy), prognostication and antenatal counselling.