[Three siblings homozygous for the transthyretin-Met30 gene in familial amyloidotic polyneuropathy--evaluation of their clinical pictures with reference to those of other 10 cases reported].
We reported clinical pictures of three siblings homozygous for a transthyretin-Met30 (TTR-Met30) gene in a family with familial amyloidotic polyneuropathy (FAP) type I residing in Kanazawa city, and evaluated their clinical pictures with reference to those of other 10 cases previously reported. Ages at onset of two homozygous patients with FAP were 58 and 68 years. They showed sensory-dominant polyneuropathy and mild autonomic dysfunctions. One of them showed vitreous opacities and the other showed multifocal white sheaths along the retinal blood vessels and obstruction of the vessels. A morphometric study of the sural nerve in one patient showed a marked reduction in both myelinated and unmyelinated nerve fiber densities. The third subject was an asymptomatic carrier aged 59 years. The studies of our cases and those in the literature have shown the clinical features of homozygotes for the TTR-Met30 gene as follows: (1) all the homozygous subjects belong to families with incomplete penetrance of the disorder; (2) the clinical features common to 10 symptomatic homozygotes are late onset, mild autonomic dysfunctions, and high frequency of ocular amyloidosis; (3) there are three asymptomatic cases. In addition to TTR-Met30 abnormality, some unknown mechanisms that control its deposition into the tissues are presumed to be involved for the onset of FAP.
Yoshinaga
T
T
Department of Internal Medicine (Neurology,), Ishikawa Prefectural Central Hospital.
Nakazato
M
M
Ikeda
S
S
Ohnishi
A
A
D000368:Aged; D000682:Amyloid / Q000235:genetics*; D017772:Amyloid Neuropathies / Q000235:genetics*; D005192:Family Health; D005260:Female; D006720:Homozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D011228:Prealbumin / Q000235:genetics*
D000682:Amyloid; D011228:Prealbumin; C041120:amyloid prealbumin