Phenotypic expressions of hereditary Transthyretin Ala97Ser related Amyloidosis (ATTR) in Taiwanese

Hui-Ching Hsu, Ming-Feng Liao, Jung-Lung Hsu, Ai-Lun Lo, Hung-Chou Kuo, Rong-Kuo Lyu, Victor Chien-Chia Wu, Chih-Wei Wang, Long-Sun Ro

The disease course and early signs specific to ATTR Ala97Ser, the most common endemic mutation in Taiwan, have not been well described. Since new medications can slow down the rate of disease progression, the early diagnosis of this heterogeneous and fatal disease becomes critical. We retrospectively reviewed the characteristics of genetically confirmed ATTR Ala97Ser patients at a tertiary referral medical center. Eight patients from 7 different families were enrolled (61.7 ± 5.5 years). Gastrointestinal symptoms, dyspnea or chest tightness, rather than sensory symptoms, were the initial symptoms in two patients (2/7 = 29%). Body weight loss (3/7 = 43%), muscle wasting (4/7 = 57%), or dysphagia (3/7 = 43%) were the consecutive symptoms. Orthostatic symptoms including orthostatic hypotension (7/7 = 100%), dizziness (6/7 = 86%) and syncope (5/7 = 71%) tended to develop in the late phase of the disease. Autonomic dysfunction was conspicuous. Cardiographic findings included a combination of ventricular wall thickening and pericardial effusion (7/7 = 100%), a granular sparkling appearance of the ventricular myocardium (4/7 = 57%), or conduction abnormalities (5/7 = 71%). This study broadens the recognition of the initial signs and symptoms, including cardiographic findings and longitudinal manifestations in Taiwanese individuals with ATTR Ala97Ser mutation. These manifestations should prompt doctors to perform further studies and make an early diagnosis.