Novel STAC3 Mutations in the First Non-Amerindian Patient with Native American Myopathy.

Grzybowski M1, Schänzer A2, Pepler A3, Heller C3,Neubauer BA1,Hahn A1.
  1. Department of Child Neurology, Justus Liebig University, Giessen, Germany.
  2. Institute of Neuropathology, Justus Liebig University, Giessen, Germany.
  3. Center for Genomics and Transcriptomics, Tuebingen, Germany.

Abstract

Native American myopathy (NAM) is an autosomal recessive congenital myopathy, up till now exclusively described in Lumbee Indians who harbor one single homozygous mutation (c.1046G>C, pW284S) in the STAC3 gene, encoding a protein important for proper excitation-contraction coupling in muscle. Here, we report the first non-Amerindian patient of Turkish ancestry, being compound heterozygous for the mutations c.862A>T (p.K288*) and c.432+4A>T (aberrant splicing with skipping of exon 4). Symptoms in NAM include congenital muscle weakness and contractures, progressive scoliosis, early ventilatory failure, a peculiar facial gestalt with mild ptosis and downturned corners of the mouth, short stature, and marked susceptibility to malignant hyperthermia. This case shows that NAM should also be considered in non-Indian patients with congenital myopathy, and suggests that STAC3 mutations should be taken into account as a potential cause of malignant hyperthermia.