Hereditary sensory neuropathy is caused by a mutation in the delta subunit of the cytosolic chaperonin-containing t-complex peptide-1 (Cct4 ) gene.
A spontaneous autosomal recessive mutation was identified in the Sprague-Dawley rat strain with an early onset sensory neuropathy. The main clinical features of the mutation (mutilated foot, mf ), detectable shortly after birth, include ataxia, insensitivity to pain and foot ulceration. The pathological features include a severe reduction in the number of sensory ganglia and fibres. This mutant is therefore an excellent model for human hereditary sensory neuropathies. Here, we demonstrate that the mf locus maps to the distal end of rat chromosome 14, a region syntenic to human 2p13-p16 and proximal mouse 11. Sequence analysis of four candidate genes in this interval revealed a 1349G>A mutation in the chaperonin (delta) subunit 4 (Cct4) gene associated with the mf mutant. This change resulted in the substitution of a highly conserved cysteine for tyrosine at amino acid 450. Although we did not identify a mutation in the human CCT4 gene in a set of HSN patients, this result clearly demonstrates the pathological consequences of a defect in Cct4, a subunit of CCT (cytosolic chaperonin-containing t-complex peptide-1), involved in folding tubulin, actin and other cytosolic proteins. This is the first report of a mutation in a molecular chaperonin causing a hereditary neuropathy and raises the possibility that mis-folding proteins may be a cause of this group of neuropathies.
Lee
Ming-Jen
MJ
Division of Clinical Neurology and Department of Molecular Pathogenesis, Institute of Neurology, Queen Square, London, WC1N 3BG, UK
Stephenson
Dennis A
DA
Groves
Michael J
MJ
Sweeney
Mary G
MG
Davis
Mary B
MB
An
Shu-Fang
SF
Houlden
Henry
H
Salih
Mustafa A M
MA
Timmerman
Vincent
V
de Jonghe
Peter
P
Auer-Grumbach
Michaela
M
Di Maria
Emilio
E
Scaravilli
Francesco
F
Wood
Nicholas W
NW
Reilly
Mary M
MM
D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D056404:Chaperonin Containing TCP-1; D018833:Chaperonins / Q000235:genetics*; D002874:Chromosome Mapping; D002889:Chromosomes, Human, Pair 2 / Q000235:genetics; D017931:DNA Primers; D004195:Disease Models, Animal; D015870:Gene Expression; D005808:Genes, Recessive; D009477:Hereditary Sensory and Autonomic Neuropathies / Q000235:genetics*; D006801:Humans; D008126:Lod Score; D008969:Molecular Sequence Data; D020125:Mutation, Missense / Q000235:genetics*; D051381:Rats; D011922:Rats, Mutant Strains; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
C533300:CCT4 protein, human; D017931:DNA Primers; C533315:Tcp1 protein, mouse; D056404:Chaperonin Containing TCP-1; D018833:Chaperonins