{Reference Type}: Case Reports
{Title}: Congenital asymmetric distal myopathy with hemifacial weakness caused by a heterozygous large de novo mosaic deletion in nebulin.
{Author}: Sagath L;Lehtokari VL;Välipakka S;Vihola A;Gardberg M;Hackman P;Pelin K;Jokela M;Kiiski K;Udd B;Wallgren-Pettersson C;
{Journal}: Neuromuscul Disord
{Volume}: 31
{Issue}: 6
{Year}: 06 2021
{Factor}: 3.538
{DOI}: 10.1016/j.nmd.2021.03.006
{Abstract}: We report the first mosaic mutation, a deletion of exons 11-107, identified in the nebulin gene in a Finnish patient presenting with a predominantly distal congenital myopathy and asymmetric muscle weakness. The female patient is ambulant and currently 26 years old. Muscle biopsies showed myopathic features with type 1 fibre predominance, strikingly hypotrophic type 2 fibres and central nuclei, but no nemaline bodies. The deletion was detected in a copy number variation analysis based on next-generation sequencing data. The parents of the patient did not carry the deletion. Mosaicism was detected using a custom, targeted comparative genomic hybridisation array. Expression of the truncated allele, less than half the size of full-length nebulin, was confirmed by Western blotting. The clinical and histological picture resembled that of a family with a slightly smaller deletion, and that in patients with recessively inherited distal forms of nebulin-caused myopathy. Asymmetry, however, was a novel feature.