A new early-onset neuromuscular disorder associated with kyphoscoliosis peptidase (KY) deficiency.

ABSTRACT: We describe a new early-onset neuromuscular disorder due to a homozygous loss-of-function variant in the kyphoscoliosis peptidase gene (KY). A 7.5-year-old girl with walking difficulties from 2 years of age presented with generalized muscle weakness; mild contractures in the shoulders, hips and feet; cavus feet; and lordosis but no scoliosis. She had previously been operated with Achilles tendon elongation. Whole-body MRI showed atrophy and fatty infiltration in the calf muscles. Biopsy of the vastus lateralis muscle showed variability in fiber size, with some internalized nuclei and numerous very small fibers with variable expression of developmental myosin heavy chain isoforms. Some small fibers showed abnormal sarcomeres with thickened Z-discs and small nemaline rods. Whole-exome sequen

SUBMITTER: Hedberg-Oldfors C 

PROVIDER: S-EPMC5117942 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature