Three Turkish families with different transthyretin mutations.

Transthyretin (TTR)-related hereditary amyloidosis, also called familial amyloid polyneuropathy (FAP), is a rare autosomal dominant systemic disorder that presents with progressive axonal sensory, autonomic and/or motor neuropathies. The present report describes three families with three different TTR mutations who were followed from 1995 to 2014. Only one of these families expressed the Val30Met mutation, which is the most common mutation in endemic regions; all members of this family had late disease onset but varied severities and clinical presentations of the disease. The second family expressed the Thr49Ser mutation, which has not been well documented previously. Our limited experience obtained from these patients indicates that this mutation presents with autonomic neuropathy but a greater degree of cardiac involvement, especially fatal heart failure. The third mutation, Glu54Lys, has been identified as a cause of severe familial amyloid polyneuropathy; the family members with this mutation exhibited severe motor and autonomic neuropathy, early vitreous opacity, and fatal heart failure. Three of the patients with the Val30Met mutation were treated with tafamidis for longer than one year and cessation of the polyneuropathy resulted. However, a short trial of tafamidis in two patients with the Glu54Lys mutation, who showed severe systemic and neurological involvement, did not gain any clinical benefits.