RESUMO Introdução: A doença de Huntington (DH), causada por uma repetição CAG expandida no HTT, não possui tratamento e biomarcadores são necessários para futuros ensaios clínicos. Objetivo: Nosso objetivo foi verificar se os níveis de carnitina livre e aminoácidos de cadeia ramificada se comportam como potenciais biomarcadores na DH. Métodos: Portadores sintomáticos e assintomáticos e controles foram recrutados. Idade, sexo, índice de massa corporal (IMC), idade de início, duração da doença, escores UHDRS e trato CAG expandido foram obtidos; valina, leucina, isoleucina e carnitina livre foram medidas. Foram realizadas análises basal e longitudinal. Resultados: Setenta e quatro portadores sintomáticos, 20 portadores assintomáticos e 22 não portadores foram incluídos. No início do estudo, os níveis de valina estavam reduzidos em portadores de DH sintomáticos e assintomáticos quando comparados aos não portadores. Não foram observadas diferenças nos níveis de carnitina livre ou isoleucina + leucina entre os grupos. O IMC dos indivíduos sintomáticos foi menor que o dos não portadores. Níveis de valina correlacionaram-se com o IMC. Avaliação de acompanhamento foi realizada em 43 indivíduos sintomáticos. A pontuação do escore motor total da UHDRS aumentou 4,8 pontos/ano em média. Não foram observadas reduções significativas no IMC ou na valina, enquanto os níveis de carnitina livre e isoleucina+leucina aumentaram. Conclusões: Embora os níveis de valina tenham sido menores nos portadores de DH e estivessem relacionados às perdas de IMC observadas em indivíduos pré-sintomáticos, nenhum desses metabólitos parece ser biomarcador para a DH.

ABSTRACT Background: Huntington’s disease (HD), caused by an expanded CAG repeat at HTT, has no treatment, and biomarkers are needed for future clinical trials. Objective: The objective of this study was to verify if free carnitine and branched chain amino acids levels behave as potential biomarkers in HD. Methods: Symptomatic and asymptomatic HD carriers and controls were recruited. Age, sex, body mass index (BMI), age of onset, disease duration, UHDRS scores, and expanded CAG tract were obtained; valine, leucine, isoleucine, and free carnitine were measured. Baseline and longitudinal analysis were performed. Results: Seventy-four symptomatic carriers, 20 asymptomatic carriers, and 22 non-carriers were included. At baseline, valine levels were reduced in symptomatic and asymptomatic HD carriers when compared to non-carriers. No difference in free carnitine or isoleucine+leucine levels were observed between groups. BMI of symptomatic individuals was lower than those of non-carriers. Valine levels correlated with BMI. Follow-up evaluation was performed in 43 symptomatic individuals. UHDRS total motor score increased 4.8 points/year on average. No significant reductions in BMI or valine were observed, whereas free carnitine and isoleucine+leucine levels increased. Conclusions: Although valine levels were lower in HD carriers and were related to BMI losses observed in pre-symptomatic individuals, none of these metabolites seem to be biomarkers for HD.

RESUMO As paraparesias espásticas hereditárias (PEH) são um grupo de doenças genéticas caracterizado por espasticidade dos membros inferiores com ou sem características neurológicas adicionais. A disfunção da deglutição é pouco estudada nas PEH e sua presença pode levar a complicações respiratórias e nutricionais significativas. Objetivo: O objetivo deste estudo foi avaliar a frequência e a caracterização clínica da disfagia em diferentes tipos de PEH. Métodos: Foi realizado um estudo transversal em dois centros. Os pacientes com PEH confirmados geneticamente foram avaliados pelo Northwestern Dysphagia Patient Check Sheet e pela Escala Funcional de Ingestão Oral. Além disso, a autopercepção da disfagia foi avaliada pelo Eat Assessment Tool-10 e pelo Swallowing Disturbance Questionnaire. Resultados: Trinta e seis pacientes com paraplegia espástica tipo 4 (SPG4), cinco com SPG11, quatro com SPG5, quatro com xantomatose cerebrotendinosa (CTX), três com SPG7 e dois com SPG3A foram avaliados. Disfagia orofaríngea leve a moderada estava presente em 3/5 (60%) dos pacientes com SPG11 e 2/4 (50%) dos pacientes com CTX. Um único SPG4 (2%) e um único SPG7 (33%) apresentaram disfagia orofaríngea leve. Todos os outros pacientes avaliados apresentaram deglutição normal ou funcional. Conclusão: Disfagia orofaríngea clinicamente significativa estava presente apenas nas formas complicadas de PEH. A SPG11 e CTX apresentaram maiores riscos de disfagia, sugerindo que a avaliação da deglutição deve fazer parte do manejo dos pacientes com essas condições.

ABSTRACT Hereditary spastic paraplegias (HSP) are a group of genetic diseases characterized by lower limb spasticity with or without additional neurological features. Swallowing dysfunction is poorly studied in HSP and its presence can lead to significant respiratory and nutritional complications. Objectives: The aim of this study was to evaluate the frequency and clinical characteristics of dysphagia in different types of HSP. Methods: A two-center cross-sectional prevalence study was performed. Genetically confirmed HSP patients were evaluated using the Northwestern Dysphagia Patient Check Sheet and the Functional Oral Intake Scale. In addition, self-perception of dysphagia was assessed by the Eat Assessment Tool-10 and the Swallowing Disturbance Questionnaire. Results: Thirty-six patients with spastic paraplegia type 4 (SPG4), five with SPG11, four with SPG5, four with cerebrotendinous xanthomatosis (CTX), three with SPG7, and two with SPG3A were evaluated. Mild to moderate oropharyngeal dysphagia was present in 3/5 (60%) of SPG11 and 2/4 (50%) of CTX patients. A single SPG4 (2%) and a single SPG7 (33%) patient had mild oropharyngeal dysphagia. All other evaluated patients presented with normal or functional swallowing. Conclusions: Clinically significant oropharyngeal dysphagia was only present in complicated forms of HSP Patients with SPG11 and CTX had the highest risks for dysphagia, suggesting that surveillance of swallowing function should be part of the management of patients with these disorders.

Abstract Huntington’s disease (HD) is due to dominant expansions of the CAG repeat of the HTT gene. Meiotic instability of the (CAG)n might impact the disorder frequency. We report on HD minimal prevalence in Rio Grande do Sul (RS) state, Brazil, and on intergenerational instability of the (CAG)n in HD families. Symptomatic and at-risk subjects from 179 HD families were ascertained between 2013 and 2016. Clinical, molecular and family history data were obtained. Expanded (CAG)n length differences between parent and child (delta-expanded-(CAG)n) were calculated. Effect of parental age on the (CAG)n instability upon transmission was inferred by correlating delta-expanded-(CAG)n between siblings to their age differences. HD minimal prevalence in RS state was estimated as 1.85:100,000 inhabitants. Alleles with (CAG)27-35 were found on 21/384 non-disease associated chromosomes (5.5%); among 253 expanded alleles, four (1.6%) were within reduced penetrance range with (CAG)36-39. In 32 direct transmissions, mean instability was larger among paternal than maternal transmissions. In direct transmissions and in 51 sibling pairs, parental age at the time of child birth were not correlated with delta-expanded-(CAG)n. Briefly, HD prevalence in RS state was lower than those reported for European populations. Expanded (CAG)n transmissions were unstable and not associated to parental age.