Epidemiology of transthyretin-associated familial amyloid polyneuropathy in the Majorcan area: Son Llàtzer Hospital descriptive study

Abstract

BackgroundTransthyretin-associated Familial Amyloid Polyneuropathy (TTR-FAP) is an autosomal dominant disease caused by the deposition of abnormal transthyretin that results from a gene mutation. Although rare worldwide, there are descriptions of several endemic foci, such as in Majorca, Balearic Islands, Spain. We aimed at describing a contemporary series of TTR-FAP patients in Son Llàtzer Hospital in Majorca from an epidemiological point of view in order to report their main clinical and laboratory characteristics.MethodsA retrospective, observational study was performed. Medical records from adult patients diagnosed with TTR-FAP from a single hospital were reviewed.ResultsOut of a total of 107 cases, 75 subjects were included: asymptomatic carriers (52.3%) and symptomatic patients (47.7%). Mean age was 58.3 years at the time of the study, and 50.7% were men. Mean age at diagnosis was 49.8 years. In addition, 42 patients (39.2%) had received a liver transplant, and time to liver transplantation was on average 29.56 months from the initial diagnosis. They all had the Val30Met mutation. The organs of the nervous system were those most frequently impaired (57.3%), and 83.9% of the symptomatic patients were fully ambulant (stage 1). Family history was reported in 69.3% of the cases, with the patient’s father being the most commonly affected relative. Comorbidities were frequent, with high blood pressure being the most common.ConclusionsOur findings provide additional information on this condition and are useful for describing the demographic features, clinical presentation, diagnosis, and natural course of TTR-FAP in Majorca.

Transthyretin familial amyloid polyneuropathy (TTR‐FAP) in Mallorca: a comparison between late‐ and early‐onset disease

“…The mean age of onset (AO) is different depending on the endemic focus, with large variations observed across different populations. The AO in our treatment center in Mallorca has previously been reported as 50 years (Reines et al, ) , although earlier AO was observed in other regions (e.g., mean AO of 34 years in Portugal) (Sousa et al, ) .…”

Epidemiology of ATTRV30M neuropathy in Cyprus and the modifier effect of complement C1q on the age of disease onset

“…The original cases of ATTRV30M neuropathy were recorded in Portugal [1], followed by reports in Sweden and Japan [5,6] which are large endemic areas with families carrying single genetic mutations [7]. Smaller endemic foci have been reported in Majorca and Cyprus [8,9]. Recent studies have also reported late onset ATTR V30M amyloidosis cases with distinct clinical phenotype in non-endemic areas [10].…”

Hereditary transthyretin amyloidosis

“…(отмечается накопление заболевания в 2 префектурах: Arao City in Kumamoto Prefecture и Ogawa Village in Nagano Prefecture); также имеются данные для Кипра -3,72 / 100 тыс. [65]. Регионы с повышенной частотой встречаемости описаны в Испании, в частности на Балеарских островах: показатель распространенности варьирует от 5 / 100 тыс.…”

“…на острове Майорка до 1 / 100 тыс. на острове Менорка [65]. ТТР-САП описан и в других регионах Испании, однако число пациентов в этих районах невелико.…”