Clinical Features of Familial Amyloidotic Polyneuropathy With Transthyretin p.Ala117Ser Mutation in Mainland China

Abstract

Objective: Our study aimed to report the clinical features of ATTR-PN with TTR p.Ala117Ser mutation in mainland China. Methods: Thirteen patients from 13 different families diagnosed with p.Ala117Ser ATTR-PN were identified from three centres. Clinical and laboratory data were retrospectively retrieved for analysis. Results: The male/female ratio was 11:2. All patients showed late onset, with the age of onset at 57.8 ± 5.8 years. The initial symptom was numbness of the lower or upper extremities in 9 patients (69.2%). Paraesthesia was present in all patients. Eleven patients (84.6%) had autonomic dysfunction. Cardiac, renal, hepatic, and ocular dysfunctions were noted in 8 (61.5%), 1 (7.7%), 2 (15.4%), and 3 (23.1%) patients, respectively. Nerve conduction studies have shown axonal-type sensorimotor polyneuropathy. The decline in sensory nerve action potentials was more noticeable than in compound muscle action potentials. The nerve damage present in the lower limbs was more severe than that in the upper limbs. Nerve biopsy revealed positive Congo red staining in 7/10 patients (70%). Conclusion: Our study is the largest population report on this rare p.Ala117Ser mutation in mainland China.