PMID- 8665724
OWN - NLM
STAT- MEDLINE
DCOM- 19960807
LR  - 20231213
IS  - 0009-918X (Print)
IS  - 0009-918X (Linking)
VI  - 35
IP  - 8
DP  - 1995 Aug
TI  - [A family of X-linked motor and sensory neuropathy with a new type of connexin32 
      mutation].
PG  - 843-9
AB  - A 28-year-old man had complaints of muscle weakness in both his legs and fingers. 
      Moderate degrees of symmetrical atrophy adn weakness of the bilateral lower 
      limbs, moderate degree of muscle atrophy was also noticed distal to the lower one 
      third of the upper thigh. A moderate degree of weakness of the anterior tibial, 
      extensor digitorum and peroneus muscles was also noted. Pes cavus deformity was 
      evident bilaterally. Knee jerk was normal, and Achilles tendon reflex was absent 
      without pathologic reflexes. He could not walk on his heels. Vibratory sensation 
      was severely decreased in the toes, and both touch and pain sensations were 
      slightly decreased on the dorsum of the feet. The median motor nerve conduction 
      velocity was 28.9 m/sec with a prolonged distal latency. An amplitude of M-wave 
      evoked by electrical stimulation of the median nerve 1 mV. No M-wave was obtained 
      from stimulation of the tibial nerve, and no sensory nerve action potentials were 
      elicited from electrical stimulation of the median and sural nerves. Histologic 
      studies of the biopsied sural nerve revealed the occasional presence of 
      internodes with a thin myelin sheath and a decrease in the density of large 
      myelinated fibers. Small and atypical onion-bulbs were occasionally observed by 
      electron microscopy. Based on the neurological examination and nerve conduction 
      study of the family members, a sister, mother and grandmother of the proband were 
      found to be mildly affected without any disability in their daily activities. 
      However, the father and an uncle on the mother's side of the proband were normal. 
      Therefore, we concluded clinically that this family had HMSN type I with 
      autosomal dominant inheritance or X-linked HMSN. In the studies of fluorescence 
      in situ hybridization and restriction fragment length polymorphism of the genomic 
      DNA of the proband, a DNA duplication in chromosome 17p11.2-12 was not observed. 
      A single-strand conformational polymorphism analysis of the genomic DNA encoding 
      connexin32 (Cx32) revealed the abnormal band different from that of the control. 
      A sequence analysis of the genomic DNA obtained by use of the polymerase chain 
      reaction was also performed. It revealed that there was a mutant allele, a 
      cytosine to thymine substitution of the nucleotide position 140, which caused a 
      substitution of leucine for serine at amino acid position 26. The proband's 
      mother was heterozygous for the mutant allele and the normal allele. This type of 
      Cx32 mutation was different from any type of Cx32 mutation reported in the 
      literature. The mutation in this family is located in the first transmembrane 
      portion of Cx32, and may alter the function of Cx32 protein, as well as lead to 
      the functional and structural abnormalities of the myelin sheath at the nodes of 
      Ranvier and Schmidt-Lanterman's incisures, where Cx32 is present. This is the 
      first Japanese X-linked HMSN family showing a new type of mutation of Cx32 gene 
      with clinical findings and a histologic evaluation of the sural nerve.
FAU - Ohnishi, A
AU  - Ohnishi A
AD  - Department of Neurology, Faculty of Medicine, Kyushu University.
FAU - Yoshimura, T
AU  - Yoshimura T
FAU - Takazawa, A
AU  - Takazawa A
FAU - Hashimoto, T
AU  - Hashimoto T
FAU - Yamamoto, T
AU  - Yamamoto T
FAU - Fukushima, Y
AU  - Fukushima Y
LA  - jpn
PT  - Case Reports
PT  - English Abstract
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Japan
TA  - Rinsho Shinkeigaku
JT  - Rinsho shinkeigaku = Clinical neurology
JID - 0417466
RN  - 0 (Connexins)
SB  - IM
MH  - Adult
MH  - Aged
MH  - Aged, 80 and over
MH  - Connexins/*genetics
MH  - Female
MH  - *Genetic Linkage
MH  - Hereditary Sensory and Motor Neuropathy/*genetics/pathology/physiopathology
MH  - Humans
MH  - Male
MH  - Middle Aged
MH  - Neural Conduction
MH  - Peripheral Nerves/pathology/physiopathology
MH  - *Point Mutation
MH  - *X Chromosome
MH  - Gap Junction beta-1 Protein
EDAT- 1995/08/01 00:00
MHDA- 1995/08/01 00:01
CRDT- 1995/08/01 00:00
PHST- 1995/08/01 00:00 [pubmed]
PHST- 1995/08/01 00:01 [medline]
PHST- 1995/08/01 00:00 [entrez]
PST - ppublish
SO  - Rinsho Shinkeigaku. 1995 Aug;35(8):843-9.