Referenced in: none

Automatically associated channels: TRP , TRPV , TRPV4

Title: Reduced penetrance in hereditary motor neuropathy caused by TRPV4 Arg269Cys mutation.

Authors: José Berciano, Jonathan Baets, Elena Gallardo, Magdalena Zimoń, Antonio Garcia, Eduardo Lopez-Laso, Onofre Combarros, Jon Infante, Vincent Timmerman, Albena Jordanova, Peter De Jonghe

Journal, date & volume: J. Neurol., 2011 Aug , 258, 1413-21

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/21336783

Abstract
Incomplete penetrance has rarely been reported in Charcot-Marie-Tooth disease. Our aim is to describe reduced penetrance in a hereditary motor neuropathy pedigree due to mutation in the transient receptor potential vallinoid 4 (TRPV4) gene. The pedigree comprised two affected members, the proband aged 44 years and her affected daughter aged 7 years, and seven additional related subjects, three of whom were subclinical gene mutation carriers aged 9, 40 and 70 years. Clinico-electrophysiological studies, MRI of lower-limb musculature and genetic testing of the TRPV4 were performed. The proband presented with a moderate facio-scapulo-peroneal syndrome, whereas her symptomatic daughter suffered from severe congenital spinal muscular atrophy with arthrogryposis, laryngomalacia, and vocal cord paresis. Electrophysiological evaluation revealed a pure motor axonal neuropathy. In the proband, MRI showed extensive and widespread fatty atrophy of lower-leg musculature, whereas in thigh musculature there was just mild distal fatty infiltration of vastus lateralis. Genetic testing revealed a heterozygous Arg269Cys mutation in the TPRV4 gene. In all three mutation carriers results from clinical and electrophysiological examination, and MRI of foot and lower-leg musculature were normal. We conclude that non-penetrance may be an integral feature of neuropathic syndromes associated with TRPV4 gene mutation.