p.Val142lle/p.Val122lle (C.424G>A) Transthyretin Mutation Presenting Exclusively As Small Fiber Neuropathy

Familial amyloid polyneuropathy is a rare autosomal dominant disorder caused by mutations in the transthyretin gene, TTR. More than 100 mutations in the TTR gene are known. p.Val30Met was identified first as a cause of FAP and is the most common mutation worldwide. p.Val30Met is associated with peripheral neuropathy while p.Val142lle (C.424G>A) (also known as p.Val122lle)  is associated with cardiac amyloidosis [1, 2, 3] . In this context, we report a patient harboring p.Val142lle mutation with exclusive small fiber neuropathy and absence of any cardiac involvement representing genotypic-phenotypic heterogenicity.