Correlation between connexin 32 gene mutations and clinical phenotype in X-linked dominant Charcot-Marie-Tooth neuropathy.
We studied the relationship between the genotype and clinical phenotype in 27 families with dominant X-linked Charcot-Marie-Tooth (CMTX1) neuropathy. Twenty-two families showed mutations in the coding region of the connexin32 (cx32) gene. The mutations include four nonsense mutations, eight missense mutations, two medium size deletions, and one insertion. Most missense mutations showed a mild clinical phenotype (five out of eight), whereas all nonsense mutations, the larger of the two deletions, and the insertion that produced frameshifts showed severe phenotypes. Five CMTX1 families with mild clinical phenotype showed no point mutations of the cx32 gene coding region. Three of these families showed positive genetic linkage with the markers of the Xq13.1 region. The genetic linkage of the remaining two families could not be evaluated because of their small size.
Ionasescu
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V
Department of Pediatrics, University of Iowa Hospitals and Clinics, Iowa City 52242, USA.
Ionasescu
R
R
Searby
C
C
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D002607:Charcot-Marie-Tooth Disease / Q000209:etiology* / Q000235:genetics; D017630:Connexins / Q000235:genetics*; D004576:Electromyography; D004594:Electrophysiology; D005260:Female; D005799:Genes, Dominant; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D014960:X Chromosome; D000097002:Gap Junction beta-1 Protein
D017630:Connexins; D000097002:Gap Junction beta-1 Protein