Charcot-Marie-Tooth disease: Genetic profile of patients from a large Brazilian neuromuscular reference center.

This study aimed to describe the clinical, genetic, and epidemiological features of Charcot-Marie-Tooth disease (CMT) in Brazilian patients from a tertiary center, and to compare our data with previously published findings. This retrospective observational study conducted between February 2015 and July 2020 evaluated 503 patients (94 families and 192 unrelated individuals), diagnosed with CMT. Clinical and neurophysiological data were obtained from electronic medical records and blood samples were used for genetic analyses. Multiplex ligation-dependent probe amplification was used to assess duplications/deletions in PMP22. Sanger sequencing of GJB1 was performed in cases of suspected demyelinating CMT. Targeted gene panel sequencing was used for the remaining negative demyelinating cases and all axonal CMT cases. The first decade of life was the most common period of disease onset. In all, 353 patients had demyelinating CMT, 39 had intermediate CMT, and 111 had axonal CMT. Pathogenic or likely pathogenic variants were identified in 197 index cases. The most common causative genes among probands were PMP22 (duplication) (n = 116, 58.88%), GJB1 (n = 23, 11.67%), MFN2 (n = 12, 6.09%), GDAP1 (n = 7, 3.55%), MPZ (n = 6, 3.05%), PMP22 (point mutation) (n = 6, 3.05%), NEFL (n = 3, 1.52%), SBF2 (n = 3, 1.52%), and SH3TC2 (n = 3, 1.52%). Other identified variants were ≤1% of index cases. This study provides further data on the frequency of CMT subtypes in a Brazilian clinical-based population and highlights the importance of rarer and previously undiagnosed variants in clinical practice.

Resposta clínica de crianças e adolescentes com osteogênese imperfeita à terapia com infusão cíclica intravenosa de pamidronato dissódico / Clinical outcomes of cyclical intravenous infusion therapy with disodium pamidronate for children and adolescents with osteogenesis imperfecta

Introdução. A osteogênese imperfeita é doença congênita rara, de origem genética, decorrente de distúrbios na síntese do colágeno tipo 1, caracterizada por graus variados de fragilidade e deformidade óssea. Objetivo. Avaliar o impacto da terapia com pamidronato sobre o número de fraturas, a dor óssea, a motricidade funcional e a prática de atividades físicas em pacientes pediátricos com osteogênese imperfeita. Método. Estudo retrospectivo dos prontuários de sessenta pacientes com osteogênese imperfeita, acompanhados no Hospital Universitário de Brasília. Foram tabelados e analisados os dados referentes ao número de pacientes com fraturas, dores ósseas, prática regular de atividades físicas e à motricidade funcional antes e depois do início da terapia com pamidronato. Resultados. Das 60 crianças avaliadas (30 do sexo feminino) com osteogênese imperfeita, 14 foram do tipo I,33 do tipo III e 13 do tipo IV. A média de idade foi 8,8 ± 4,5 anos e média de idade ao diagnóstico, 3,1 ± 4,1 anos.Desses, 55 ingressaram no protocolo para recebimento do pamidronato. Depois do início da terapia, o número de doentes que tiveram fraturas reduziu-se de 55 para 17; o número de casos com dores ósseas constantes decresceu de 39 para 8; o de pacientes com prática regular de atividade física subiu de 12 para 38 e todos tiveram melhora damotricidade funcional. Todas essas diferenças foram estatisticamente ignificativas. Conclusão. O uso de pamidronato está relacionado à diminuição estatisticamente significativa de fraturas e de dores ósseas, à melhora da motricidade funcional e à regularidade de bons desempenhos físicos em indivíduos com osteogênese imperfeita, com repercussão positiva em sua integração social.

Introduction. Osteogenesis imperfecta is a rare congenital disease, of genetic inheritance, secondary to disturbanceson type 1 collagen synthesis, and characterized by a wide spectrum of bone fragilities and deformities. Objective. To evaluate the impact of pamidronate therapy on the number of fractures, bone pain complaints, functional motor mobility and on the practice of physical activities among pediatric patients with osteogenesis imperfecta. Method. Retrospective study of the records from the sixty patients with osteogenesis imperfecta followed at Hospital Universitário de Brasília. The data relating to the number of patients presenting fractures, bone pain andwith customary physical activities and to their functional mobility before and after pamidronate therapy were set and analyzed. Results. From the 60 children (30 females) with osteogenesis imperfecta, 14 were type I, 33 type III and 13 type IV. Mean age was 8.8 ± 4.5 years and mean age at diagnosis was 3.1 ± 4.1 years. Fifty-five patients were admitted to the pamidronate protocol. After the therapy has started, the number of patients presenting fractures decreased from55 to 17, presenting constant bone pain went from 39 to 8, with customary physical activities increased from 12 to 38 and all of them presented optimized functional motor mobility. All these differences were statistically significant. Conclusion. The use of pamidronate is related to a statistically significant decrease in fractures and bone pains and improvement on functional mobility and on regular practice of physical activity among patients with osteogenesis imperfecta, leading to a positive repercussion on their social integration.