Familial Transthyretin Amyloidosis with Variant Asp38Ala Presenting with Orthostatic Hypotension and Chronic Diarrhea

A 53-year-old man complained of orthostatic, non-rotating dizziness, and chronic watery diarrhea of several years duration. His nerve-conduction velocity test revealed peripheral sensory-motor polyneuropathy and he showed an autonomic function abnormality. Echocardiographic examination showed ventricular and atrial wall thickening with a granular "sparkling" appearance. Left ventricular systolic function was preserved but pseudonormal diastolic dysfunction was present. Coronary angiography showed normal coronary arteries and an endomyocardial biopsy revealed lesions consistent with cardiac amyloidosis. Colonoscopic biopsy also revealed the deposition of amyloid fibrils. Gene analysis found the transthyretin variant Asp38Ala. His son had same mutation, but three daughters did not. In conclusion, we report a case of familial transthyretin amyloidosis with Asp38Ala.