Familial amyloidotic polyneuropathy. TTR Met 30 in Majorca (Spain)

We analyzed data from 78 Majorcan patients with familial amyloidotic polyneuropathy (FAP): 57 confirmed and 21 non-confirmed. Diagnosis was established in the first group by histopathological study or detection of the biochemical marker in serum, and in the second was sup-ported by clinical information and family history. Eighteen confirmed patients were isolated cases and 39 had a family history of FAP. Age of onset was 46. 7 years; later in males; predominance of males (72%) and late on-set cases (65%). The TTR variant was Met 30 associated with haplotype I. Initial sensorimotor syndrome was present only in 55% of patients. Multiple progressive handicaps appeared. Duration averaged 10.5 years and was longer in males. Prevalence rate was 3.3 patients per 100,000 and asymptomatic carriers were 83. Twelve patients underwent liver transplantation. Since 1989, the number of FAP families, patients, prevalence, isolated cases and municipalities with affected families was increased. One founder hypothesis is supported; the mutation probably arrived from Portugal. The Majorcan focus is the fifth largest in the world. Age of onset lies between that of Sweden and those of Portugal, Japan and Brazil. Early diagnosis is very important for the possible indication of liver transplantation. FAP constitutes a public health problem in Majorca.