Perfil clínico-epidemiológico e genético de pessoas com atrofia muscular espinhal no estado de Sergipe, Brasil

Abstract

INTRODUCTION: Spinal Muscular Atrophy (SMA) is a group of neuromuscular disorders characterized by degeneration and progressive loss of function of motor neurons. SMA 5q represents the most frequent cause of infant death due to a monogenic condition and, being a genetic disease, its diagnosis is based on laboratory tests of a molecular genetic nature. OBJECTIVE: It is to evaluate the clinical-epidemiological and genetic profile of people with SMA treated at the Medical Genetics outpatient clinics of the Federal University of Sergipe (UFS), Brazil. MATERIALS AND METHODS: This is an epidemiological, observational and quantitative study. The information was obtained from a structured questionnaire developed by the researchers. RESULTS: 15 patients affected by SMA were included. There was a predominance of female people (73%), self-declared mixed race (53%), residents of Aracaju (47%) and with a family income of less than two minimum wages (73%). The majority of participants did not perform paid work (93%). In relation to the clinical phenotype of SMA, two type I cases (13%), eight type II cases (53%) and five type III cases (33%) were observed among the participants. It was also observed that in 85% of the participants there was a homozygous deletion of SMN1. Of the total, two individuals with SMA showed heterozygosity of SMN1. In the sample, 13 participants have access to drug treatment for SMA, which represents 87% of the sample, with 11 using nusinersen and two using risdiplam. DISCUSSION: The correlation between the number of copies of the SMN2 gene and the phenotype resembled the pattern described in the literature. Despite this, although there is a strong correlation, the relationship with the number of copies of SMN2 is not deterministic and does not occur in all cases. According to INAME (2022), SMA type I is the most prevalent in the country, however in the studied sample there was a predominance of individuals with SMA type II (53%), compared to the other types: I (13%) and III (33%). It is evident in the literature that there is an apparent delay between the onset of SMA symptoms and the diagnostic confirmation of the disease. CONCLUSION: A multidisciplinary approach is crucial in the management of patients with SMA. To date, there is no cure, but there are therapeutic options that can modify the natural evolution of the disease. The results are variable, but it is known that starting treatment early is related to a better prognosis.