ClinVar

In a Japanese patient with familial cardiac amyloidosis (105210), Nishi et al. (1992) demonstrated a ser50-to-ile mutation in the TTR gene resulting from a G-to-T transversion. The patient had 2 sibs out of 8 who had died with cardiac amyloidosis. Electrocardiogram showed first-degree atrioventricular block and complete left bundle branch block. Two-dimensional echocardiography showed symmetrical left ventricular hypertrophy with preserved systolic function. The thickened cardiac walls demonstrated a granular sparkling texture. Amyloid deposits were found in biopsy specimens from the rectum and skin. None of the 3 patients showed evident polyneuropathy.

In a Japanese patient with amyloid polyneuropathy, Saeki et al. (1992) used SSCP analysis of PCR products to demonstrate mutation in exon 3. Direct sequencing demonstrated a G-to-T transversion resulting in substitution of isoleucine for serine-50. See 176300.0013 for another mutation affecting serine-50 in a Japanese patient. Saeki et al. (1992) described their patient as a 56-year-old Japanese woman living in Oita Prefecture who had a 7-year history of sensory disturbance and muscular atrophy in the lower limbs. The autonomic dysfunction, especially orthostatic hypotension, limited her ambulation. Amyloid deposition was proven by sural nerve biopsy,