SUMMARY OBJECTIVE: The objectives of this study were to translate and cross-culturally adapt the telehealth usability questionnaire into Brazilian Portuguese and to evaluate its psychometric properties. METHODS: This was a methodological validation study carried out in two phases. In phase 1, the telehealth usability questionnaire was cross-culturally adapted with 10 participants comprising the expert committee members, including 5 healthcare professionals with theoretical and practical knowledge of telehealth, 1 methodologist, and 4 translators. This phase was performed at Universidade Federal de Juiz de Fora Physiotherapy Clinic School. In phase 2, the psychometric properties of telehealth usability questionnaire Brazil were analyzed. This phase included in-person assessments at Márcio Cunha Hospital, Minas Gerais. The recruitment period for both phases was from April 2020 to February 2021. Content validity, reliability, internal consistency, and criterion validity were analyzed. The criterion validity was evaluated using correlation with a validated instrument: the system usability scale. RESULTS: The telehealth usability questionnaire was adequately translated and cross-culturally adapted. The telehealth usability questionnaire Brazil presented an excellent content validity index of 0.96 with percentages of understanding higher than 90%. The telehealth usability questionnaire Brazil demonstrated great internal consistency (α=0.94 and ω=0.94), excellent intra-rater reliability (intraclass correlation coefficient=0.85, 95%CI 0.75–0.91), no difference between the test and retest [T (0.425), p>0.673], and no proportional bias (p=0.205). There was a moderate correlation between telehealth usability questionnaire Brazil and the system usability scale (r=0.52, p<0.0001). CONCLUSION: The telehealth usability questionnaire was adequately translated and cross-culturally adapted into Brazilian Portuguese and showed adequate psychometric properties for use in telehealth clinical practice and research in Brazilian-Portuguese-speaking individuals. OBJECTIVE crossculturally cross culturally METHODS members methodologist translators School 2 analyzed inperson person Hospital Gerais 202 2021 instrument RESULTS 096 0 96 0.9 90 90% α=0.94 α094 α 94 (α=0.9 ω=0.94, ω094 ω ω=0.94 , ω=0.94) intrarater intra rater intraclass coefficient085 coefficient 85 coefficient=0.85 95CI CI 95 0.75–0.91, 075091 0.75–0.91 75 91 0.75–0.91) T 0.425, 0425 0.425 425 (0.425) p>0.673, p0673 p p>0.673 673 p>0.673] p=0.205. p0205 p=0.205 . 205 (p=0.205) r=0.52, r052 r 52 (r=0.52 p<0.0001. p00001 p<0.0001 0001 p<0.0001) CONCLUSION BrazilianPortuguesespeaking speaking individuals 20 09 9 0. α=0.9 α09 (α=0. ω09 ω=0.9 coefficient08 8 coefficient=0.8 07509 0.75–0.9 7 042 0.42 42 (0.425 p067 p>0.67 67 p020 p=0.20 (p=0.205 r=0.52 r05 (r=0.5 p0000 p<0.000 000 α=0. α0 (α=0 ω0 ω=0. coefficient0 coefficient=0. 0750 0.75–0. 04 0.4 (0.42 p06 p>0.6 6 p02 p=0.2 (p=0.20 r=0.5 r0 (r=0. p000 p<0.00 00 α=0 (α= ω=0 coefficient=0 075 0.75–0 (0.4 p0 p>0. p=0. (p=0.2 r=0. (r=0 p00 p<0.0 α= (α ω= coefficient= 07 0.75– (0. p>0 p=0 (p=0. r=0 (r= p<0. 0.75 (0 p> p= (p=0 r= (r p<0 0.7 ( (p= p< (p

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.

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.