RESUMO
BACKGROUND AND AIMS: X-linked Charcot-Marie-Tooth disease type 6 (CMTX6) is an extremely rare condition associated with mutations in the PDK3 gene. To date, only three families from different countries have been reported (Australia, South Korea, and Germany). In this study, we sought to provide a comprehensive clinical and electrophysiological characterization of two Brazilian families. METHODS: We conducted comprehensive clinical assessments, extensive electrophysiological evaluations, and performed whole-exome sequencing in the probands to investigate the genetic basis of the disease. RESULTS: Males in the family carrying the Arg162His mutation displayed early-onset motor and/or sensory axonal neuropathy, absence of tendon jerks, pes cavus, and frequently reported pain. Females in the same family exhibited a milder phenotype of the disease with later onset and some remained asymptomatic into their 50s. In the unrelated family with a single affected male, the clinical presentation was characterized by severe progressive sensorimotor polyneuropathy accompanied by neuropathic pain. INTERPRETATION: We report two Brazilian families with CMTX6 including one harboring a previously unpublished variant in the PDK3 gene, which co-segregates with the disease as expected in a X-linked disease. Notably, the clinical presentations across the five families with available descriptions, including our study, share striking similarities. Furthermore, the proximity of the three reported mutations suggests potential functional similarities and common underlying mechanisms. This study contributes to the growing knowledge of CMTX6 and underscores the importance of international collaborations in studying rare genetic disorders.
Assuntos
Doença de Charcot-Marie-Tooth , Piruvato Desidrogenase Quinase de Transferência de Acetil , Feminino , Humanos , Masculino , Brasil , Doença de Charcot-Marie-Tooth/genética , Mutação/genética , Linhagem , Fenótipo , Piruvato Desidrogenase Quinase de Transferência de Acetil/genéticaRESUMO
Hereditary motor and sensory neuropathy, also known as Charcot-Marie-Tooth disease (CMT), traditionally refers to a group of genetic disorders in which neuropathy is the main or sole feature. Its prevalence varies according to different populations studied, with an estimate between 1:2,500 to 1:10,000. Since the identification of PMP22 gene duplication on chromosome 17 by Vance et al., in 1989, more than 100 genes have been related to this group of disorders, and we have seen advances in the care of patients, with identification of associated conditions and better supportive treatments, including clinical and surgical interventions. Also, with discoveries in the field of genetics, including RNA interference and gene editing techniques, new treatment perspectives begin to emerge. In the present work, we report the most import landmarks regarding CMT research in Brazil and provide a comprehensive review on topics such as frequency of different genes associated with CMT in our population, prevalence of pain, impact on pregnancy, respiratory features, and development of new therapies.
A neuropatia sensitivo-motora hereditária, também conhecida como doença de Charcot-Marie-Tooth (CMT), tradicionalmente se refere a um grupo de doenças genéticas em que a neuropatia é a principal ou única manifestação. Sua prevalência varia de acordo com as diferentes populações estudadas, com estimativa entre 1:2.500 a 1:10.000. Desde a identificação da duplicação do gene PMP22 no cromossomo 17, por Vance et al., em 1989, mais de 100 genes foram relacionados a esse grupo de doenças e temos visto avanços no atendimento aos pacientes, com identificação de condições associadas e melhores tratamentos de suporte, incluindo intervenções clínicas e cirúrgicas. Além disso, com as descobertas no campo da genética, incluindo técnicas de interferência de RNA e de edição genética, novas perspectivas de tratamento começaram a surgir. No presente trabalho, relatamos os marcos mais importantes sobre a pesquisa de CMT no Brasil e fornecemos uma revisão abrangente sobre tópicos como frequência de diferentes genes associados à CMT em nossa população, prevalência de dor, impacto na gravidez, alterações respiratórias e desenvolvimento de novas terapias.
Assuntos
Doença de Charcot-Marie-Tooth , Neuropatia Hereditária Motora e Sensorial , Humanos , Doença de Charcot-Marie-Tooth/genética , Doença de Charcot-Marie-Tooth/terapia , BrasilRESUMO
Abstract Hereditary motor and sensory neuropathy, also known as Charcot-Marie-Tooth disease (CMT), traditionally refers to a group of genetic disorders in which neuropathy is the main or sole feature. Its prevalence varies according to different populations studied, with an estimate between 1:2,500 to 1:10,000. Since the identification of PMP22 gene duplication on chromosome 17 by Vance et al., in 1989, more than 100 genes have been related to this group of disorders, and we have seen advances in the care of patients, with identification of associated conditions and better supportive treatments, including clinical and surgical interventions. Also, with discoveries in the field of genetics, including RNA interference and gene editing techniques, new treatment perspectives begin to emerge. In the present work, we report the most import landmarks regarding CMT research in Brazil and provide a comprehensive review on topics such as frequency of different genes associated with CMT in our population, prevalence of pain, impact on pregnancy, respiratory features, and development of new therapies.
Resumo A neuropatia sensitivo-motora hereditária, também conhecida como doença de Charcot-Marie-Tooth (CMT), tradicionalmente se refere a um grupo de doenças genéticas em que a neuropatia é a principal ou única manifestação. Sua prevalência varia de acordo com as diferentes populações estudadas, com estimativa entre 1:2.500 a 1:10.000. Desde a identificação da duplicação do gene PMP22 no cromossomo 17, por Vance et al., em 1989, mais de 100 genes foram relacionados a esse grupo de doenças e temos visto avanços no atendimento aos pacientes, com identificação de condições associadas e melhores tratamentos de suporte, incluindo intervenções clínicas e cirúrgicas. Além disso, com as descobertas no campo da genética, incluindo técnicas de interferência de RNA e de edição genética, novas perspectivas de tratamento começaram a surgir. No presente trabalho, relatamos os marcos mais importantes sobre a pesquisa de CMT no Brasil e fornecemos uma revisão abrangente sobre tópicos como frequência de diferentes genes associados à CMT em nossa população, prevalência de dor, impacto na gravidez, alterações respiratórias e desenvolvimento de novas terapias.