Etiological investigation of genetic cause in autism spectrum disorder / Investigação etiológica de causa genética na perturbação do espetro do autismo

AIMS: The aims of this study were to characterize the etiological investigation of genetic cause in the autism spectrum disorder and to determine the factors related to its identification. METHODS: A retrospective descriptive study, with an analytical component, included children and adolescents with autism spectrum disorder followed in consultation at a level 2 hospital, between November 2017 and October 2019. The following variables were analyzed: age, sex, age at the first consultation, family history, objective examination, cognitive assessment, etiological investigation of genetic cause and etiological diagnosis of genetic cause. Statistical analysis was performed using the SPSS®v23 program (significance level 0.05). RESULTS: We identified 153 children with autism spectrum disorder, of which 48 underwent a genetic cause investigation: 45 performed microarray analysis (15.6% pathogenic); 42 carried out a molecular study of the Fragile X syndrome (one altered); two performed sequencing of the methyl CpG binding protein 2 (MECP2) gene (one altered). The diagnosis of genetic cause was made in 18.8% of the sample. The identification of the etiology of a genetic cause was related to global development delay/ intellectual disability (p = 0.04) and the presence of relevant family history (p = 0.005). CONCLUSIONS: The diagnostic yield of the genetic study was higher in patients with a global development delay /intellectual disability and in patients with relevant family history.

OBJETIVOS: Os objetivos deste estudo foram caracterizar a investigação etiológica de causa genética na perturbação do espetro do autismo e determinar os fatores que se relacionam com a sua identificação. MÉTODOS: Um estudo retrospetivo descritivo, com componente analítica, incluiu crianças e adolescentes com perturbação do espetro de autismo seguidos em consulta num hospital nível 2 entre novembro de 2017 e outubro de 2019. As seguintes variáveis foram analisadas: idade, sexo, idade na primeira consulta, antecedentes familiares, exame objetivo, avaliação cognitiva, investigação etiológica de causa genética e diagnóstico etiológico de causa genética. A análise estatística foi realizada utilizando o programa SPSS®v23 (nível de significância 0,05). RESULTADOS: Identificámos 153 crianças com perturbação do espetro de autismo, das quais 48 realizaram investigação etiológica de causa genética: 45 realizaram microarray (alterações patogénicas 15,6%); 42 realizaram estudo molecular da síndrome X-Frágil (um alterado); dois realizaram sequenciação do gene MECP2 (um alterado). O diagnóstico de causa genética foi feito em 18,8% da amostra. A identificação de etiologia de causa genética relacionou-se com défice intelectual/atraso global do desenvolvimento psicomotor (p=0,04) e com a presença de antecedentes familiares relevantes (p=0,005). CONCLUSÕES: A rentabilidade diagnóstica do estudo genético foi superior em doentes com atraso global do desenvolvimento psicomotor/défice intelectual associado e com antecedentes familiares relevantes.

PREPUBERTAL GYNECOMASTIA: A RARE MANIFESTATION OF MYOTONIC DYSTROPHY TYPE 1.

OBJECTIVE: To present a case of bilateral gynecomastia in a prepubertal boy with autism spectrum disorder, diagnosed with myotonic dystrophy type 1. CASE DESCRIPTION: A 12-year-old boy with autism spectrum disorder presented at a follow-up visit with bilateral breast growth. There was a family history of gynecomastia, cataracts at a young age, puberty delay, and myotonic dystrophy type 1. The physical examination showed that he had bilateral gynecomastia with external genitalia Tanner stage 1. Neurologic examination was regular, without demonstrable myotonia. The analytical study revealed increased estradiol levels and estradiol/testosterone ratio. After excluding endocrine diseases, the molecular study of the dystrophia myotonica protein kinase gene confirmed the diagnosis of myotonic dystrophy type 1. COMMENTS: A diagnosis of prepubertal gynecomastia should include an investigation for possible underlying diseases. This case report highlights the importance of considering the diagnosis of myotonic dystrophy type 1 in the presence of endocrine and neurodevelopmental manifestations.

Prepubertal gynecomastia: a rare manifestation of myotonic dystrophy type 1 / Ginecomastia pré-púbere: uma manifestação rara da distrofia miotônica tipo 1

ABSTRACT Objective: To present a case of bilateral gynecomastia in a prepubertal boy with autism spectrum disorder, diagnosed with myotonic dystrophy type 1. Case description: A 12-year-old boy with autism spectrum disorder presented at a follow-up visit with bilateral breast growth. There was a family history of gynecomastia, cataracts at a young age, puberty delay, and myotonic dystrophy type 1. The physical examination showed that he had bilateral gynecomastia with external genitalia Tanner stage 1. Neurologic examination was regular, without demonstrable myotonia. The analytical study revealed increased estradiol levels and estradiol/testosterone ratio. After excluding endocrine diseases, the molecular study of the dystrophia myotonica protein kinase gene confirmed the diagnosis of myotonic dystrophy type 1. Comments: A diagnosis of prepubertal gynecomastia should include an investigation for possible underlying diseases. This case report highlights the importance of considering the diagnosis of myotonic dystrophy type 1 in the presence of endocrine and neurodevelopmental manifestations.

RESUMO Objetivo: Apresentar o caso de um adolescente pré-púbere com ginecomastia bilateral e transtorno do espectro autista, diagnosticado com distrofia miotônica tipo 1. Descrição do caso: Adolescente do sexo masculino de 12 anos, com transtorno do espectro autista, observado em consulta de seguimento por crescimento mamário bilateral. O paciente tinha antecedentes familiares de ginecomastia, catarata em idade jovem, atraso pubertário e distrofia miotônica tipo 1. À observação física, apresentava ginecomastia bilateral estádio 1 de Tanner. O exame neurológico era normal, sem miotonia aparente. O estudo analítico mostrou níveis elevados de estradiol e da relação estradiol/testosterona. Após exclusão de causas endócrinas, o estudo molecular do gene DMPK confirmou o diagnóstico de distrofia miotônica tipo 1. Comentários: Perante um quadro de ginecomastia pré-púbere, deve-se excluir doenças subjacentes. Este caso reforça a importância de considerar o diagnóstico de distrofia miotônica tipo 1 na presença de manifestações endócrinas e do neurodesenvolvimento.