Dados do Trabalho

Título

FAMILY AMYLOIDOTIC POLYNEUROPATHY: A RARE DISEASE INCREASINGLY COMMON

RESUMO

CASE PRESENTATION
A 76-year-old man, from Guanambi-BA, born in Cansanção-BA, with kidney disease and heart disease, with an implantable cardioverter-defibrillator, with symmetrical paresthesia and dysesthesia in gloves and boots, in addition to dysautonomia with episodes of syncope, which had been worsening for about 1 year. On neurologic examination, moderate symmetrical distal hypopalesthesia and gait of small steps with wide base without support. Four-limb ENMG (26/04/2022) showed chronic polyneuropathy with axonal predominance in the lower limbs, distal and proximal involvement, symmetrical, moderate to severe. The transthoracic echocardiogram showed significant biatrial enlargement, absence of intracavitary thrombi, diastolic dysfunction, significant left ventricular hypertrophy, minimal pericardial effusion and mild to moderate mitral regurgitation. Myocardial pyrophosphate scintigraphy (26/04/22): strongly suggestive of amyloidosis. The panel for transthyretin-linked hereditary amyloidosis revealed susceptibility to amyloidosis, variant val142Ile. The Fabry test was negative. Tafamidis meglumine 80 mg/day was requested for his treatment. The investigation of first-degree relatives (ongoing) has so far revealed two asymptomatic susceptible cases.
DISCUSSION
Familial Amyloid Polyneuropathy (FAP) is a rare multisystem disease characterized by an autosomal dominant transmission, in which the mutant form of transthyretin (TTR) is synthesized in the liver. More commonly, FAP presents in clinical conditions of varying forms and intensities that mix familial amyloidotic polyneuropathy and familial amyloidotic cardiomyopathy. The diagnosis is clinical and based on the presence of the genetic mutation in TTR. In the case in question, the changes were compatible with FAP, whose variant val142Ile is predominantly associated with cardiomyopathy, renal dysfunction and polyneuropathy.
FINAL COMMENTS
The diagnosis of FAP at a pre-clinical stage has an important epidemiological value, aiming at mapping the mutation in the community. In addition, the early initiation of treatment is related to the symptomatic improvement of the patient, minimizing the evolution of the disease. The dissemination of information and accessibility to genetic tests has led to an increase in the incidence of FAP, which becomes a possible etiology in the face of polyneuropathies without a specific cause.