GNE myopathy: current update and future therapy.

Abstract

GNE myopathy is an autosomal recessive muscle disease caused by biallelic mutations in GNE, a gene encoding for a single protein with key enzymatic activities, UDP-N-acetylglucosamine 2-epimerase and N-acetylmannosamine kinase, in sialic acid biosynthetic pathway. The diagnosis should be considered primarily in patients presenting with distal weakness (foot drop) in early adulthood (other onset symptoms are possible too). The disease slowly progresses to involve other lower and upper extremities' muscles, with marked sparing of the quadriceps. Characteristic findings on biopsies of affected muscles include 'rimmed' (autophagic) vacuoles, aggregation of various proteins and fibre size variation. The diagnosis is confirmed by sequencing of the GNE gene. Note that we use a new mutation nomenclature based on the longest transcript (GenBank: NM_001128227), which encodes a 31-amino acid longer protein than the originally described one (GenBank: NM_005476), which has been used previously in most papers. Based upon the pathophysiology of the disease, recent clinical trials as well as early gene therapy trials have evaluated the use of sialic acid or N-acetylmannosamine (a precursor of sialic acid) in patients with GNE myopathy. Now that therapies are under investigation, it is critical that a timely and accurate diagnosis is made in patients with GNE myopathy.

• Authors: Ichizo Nishino, Nuria Carrillo-Carrasco, Zohar Argov
• Journal: Journal of neurology, neurosurgery, and psychiatry (J Neurol Neurosurg Psychiatry) Vol. 86 Issue 4 Pg. 385-92 (Apr 2015) ISSN: 1468-330X [Electronic] England
• PMID: 25002140 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't, Review)
• Copyright: Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Chemical References

• Multienzyme Complexes
• UDP-N-acetylglucosamine 2-epimerase - N-acetylmannosamine kinase

Topics

• Animals
• Clinical Trials as Topic
• Disease Models, Animal
• Distal Myopathies (diagnosis, epidemiology, genetics, pathology, therapy)
• Humans
• Mice
• Multienzyme Complexes (genetics)