Amyloidosis due to TTR mutations in Mexico with 4 distincts genotypes in the index cases

BACKGROUND: Transthyretin-related hereditary amyloidosis (ATTR) is a systemic disease characterized by extracellular deposits of amyloid due to the autosomal dominant inheritance of a mutation in the TTR gene (18q12.1). Although described worldwide, it is a rare disease, limited to certain parts of the world. The aim of this manuscript is to describe the presence and characteristics of ATTR in Mexico. METHODS: From 2010 through the database of the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán we selected cases that had the diagnosis of “amyloidosis”, with any etiology, reviewed the files and selected those with suspected hereditary etiology. RESULTS: We identified 111 subjects with 5 different pathological mutations, none of them with the classic Val30Met mutation. Mutations found were Ser50Arg in 83 (74%), Gly47Ala in 14 (13%), Ser52Pro in 12 (11%) and V122I /Y116H in 2 (2%). The majority of positive patients were from the States of Morelos and Guerrero. Twenty different families were included. The most common causes of death was urosepsis and cardiac failure. CONCLUSIONS: In Mexico there are endemic foci of ATTR, mainly in the states of Morelos and Guerrero. The major mutations are different from the most common global mutation Met30Val.