Association between attention-deficit/hyperactivity symptoms and sleep in preschoolers.

INTRODUCTION: Sleep problems are frequent in children with attention-deficit/hyperactivity disorder (ADHD). Some authors have tried to characterize paediatric sleep habits in Portugal, but none has focused on preschool-age children nor attempted to establish their association with ADHD. We aimed to assess the prevalence of ADHD symptoms in preschool-age children and to study their association with sleep habits. MATERIAL AND METHODS: We conducted a cross-sectional study. We distributed questionnaires to a random sample of caregivers of children enrolled in early childhood education centres in Porto. We collected data on sociodemographic characteristics, television watching and outdoor activities. We assessed ADHD symptoms and sleep habits with the Portuguese versions of the Conners' Parents Rating Scale, Revised and the Children's Sleep Habits Questionnaire (CSHQ-PT), respectively. RESULTS: The study included 381 preschoolers (50.90% male). We found high scores for ADHD symptoms in 13.10%, with a higher prevalence in girls (14.40% vs. 11.85%; P = 0.276). In the CSHQ-PT, 45.70% of participants had a mean total score greater than 48, which is the cut-off point applied in the screening of sleep disturbances in the Portuguese population. There was a significant association between high scores for ADHD symptoms and a lower maternal education level (P < 0.001), a shorter sleep duration (P = 0.049), and higher scores on parasomnias (P = 0.019) and sleep disordered breathing (P = 0.002) in CSHQ-PT subscales. CONCLUSIONS: ADHD and sleep disorders are common in preschoolers, in Porto, and this study suggests some clinical correlations between them. Since these interactions are complex and far from being elucidated, further studies are paramount to provide guidance for prevention and managing strategies in younger children at risk for ADHD.

[Congenital adrenal hyperplasia due to 21-hydroxylase deficiency: genotype-phenotype correlation]. / Hiperplasia Congénita da Suprarrenal por Deficiência de 21-Hidroxílase: Correlação Genótipo-Fenótipo.

INTRODUCTION: Congenital adrenal hyperplasia due to 21-hydroxylase deficiency is one of the most frequent inborn conditions. It is caused by distinct mutations in the CYP21A2 gene and in the majority of cases the disease's severity correlates with CYP21A2 allelic variation Our aim was to describe the mutational spectrum of CYP21A2 and evaluate genotype-phenotype correlation in a cohort of portuguese patients with 21-hydroxylase deficiency. MATERIAL AND METHODS: Retrospective study of 22 patients with clinical diagnosis of 21-hydroxylase deficiency. Molecular analysis of CYP21A2 was performed and genotype-phenotype correlation was then established. RESULTS: Genotyping was performed in 22 unrelated patients: 5 with classic salt-wasting (average age of diagnosis 10,2 days; minimum 1, maximum 20 days), 7 with classic simple virilizing (average age of diagnosis 3,5 years; minimum 0 days, maximum 7 years) and 10 with nonclassical form (average age of diagnosis 5,7 years; minimum 4 years, maximum 8 years). The most frequent genetic defects in the classic forms were I2 splice (24%) and I172N (24%), followed by Q318X (16%) and gene deletions (16%) and in the nonclassical form, the V281L (80%). The overall concordance between genotype and phenotype was 81,8%. Genotype accurately predicted phenotype in 83,3%, 100% and 90% of patients with classic salt-wasting, classic simple virilizing and nonclassical mutations, respectively. DISCUSSION: The frequency of genetic defects in our patients was comparable to similar studies. In most cases there was a good correlation between genotype and phenotype. CONCLUSIONS: Molecular analysis of CYP21A2 provides useful information in terms of prediction of disease severity, genetic and prenatal counseling.

Introdução: A hiperplasia congénita da suprarrenal por deficiência de 21-hidroxílase constitui uma das doenças hereditárias mais comuns. Resulta de diferentes mutações no gene CYP21A2 e, na maioria dos casos, a gravidade da doença correlaciona-se com a variação alélica do CYP21A2. O objetivo deste estudo foi descrever o espectro mutacional do CYP21A2 e avaliar a correlação genótipo-fenótipo numa coorte de doentes portugueses com deficiência de 21-hidroxílase. Material e Métodos: Estudo retrospetivo de 22 doentes com diagnóstico clínico de deficiência de 21-hidroxílase. Foi feita análise molecular do CYP21A2 e estabelecida a correlação genótipo-fenótipo. Resultados: Foi realizada genotipagem em 22 doentes não relacionados: 5 com a forma clássica perdedora de sal (idade média ao diagnóstico de 10,2 dias; mínimo 1, máximo 20 dias), 7 com a forma clássica virilizante simples (idade média ao diagnóstico de 3,5 anos; mínimo 0 dias, máximo 7 anos) e 10 com a forma não clássica (idade média ao diagnóstico de 5,7 anos; mínimo 4 anos, máximo 8 anos). Os defeitos genéticos mais frequentes nas formas clássicas foram o I2 splice (24%) e I172N (24%), seguindo-se o Q318X (16%) e deleções de genes (16%) e, na forma não clássica, o V281L (80%). Verificou-se uma concordância genótipo-fenótipo global de 81,8%. O genótipo permitiu prever adequadamente o fenótipo em 83,3%, 100% e 90% dos doentes com mutações compatíveis com a forma clássica perdedora de sal, clássica virilizante simples e não clássica, respectivamente. Discussão: A frequência de defeitos genéticos observados nos nossos doentes é comparável a estudos semelhantes. Observou-se, na maioria dos casos, uma boa correlação genótipo-fenótipo. Conclusões: A análise molecular do CYP21A2 fornece informação importante relativamente à gravidade da doença e no aconselhamento genético e pré-natal.