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Abstract Background Sexual dimorphism in DNA methylation levels is a recurrent epigenetic feature in different human cell types and has been implicated in predisposition to disease, such as psychiatric and autoimmune disorders. To elucidate the genetic origins of sex-specific DNA methylation, we examined DNA methylation levels in fibroblast cell lines and blood cells from individuals with different combinations of sex chromosome complements and sex phenotypes focusing on a single autosomal region––the differentially methylated region (DMR) in the promoter of the zona pellucida binding protein 2 (ZPBP2) as a reporter. Results Our data show that the presence of the sex determining region Y (SRY) was associated with lower methylation levels, whereas higher X chromosome dosage in the absence of SRY led to an increase in DNA methylation levels at the ZPBP2 DMR. We mapped the X-linked modifier of DNA methylation to the long arm of chromosome X (Xq13-q21) and tested the impact of mutations in the ATRX and RLIM genes, located in this region, on methylation levels. Neither ATRX nor RLIM mutations influenced ZPBP2 methylation in female carriers. Conclusions We conclude that sex-specific methylation differences at the autosomal locus result from interaction between a Y-linked factor SRY and at least one X-linked factor that acts in a dose-dependent manner.

OBJECTIVE: Literature review of new genes related to osteogenesis imperfecta (OI) and update of its classification. SOURCES: Literature review in the PubMed and OMIM databases, followed by selection of relevant references. SUMMARY OF THE FINDINGS: In 1979, Sillence et al. developed a classification of OI subtypes based on clinical features and disease severity: OI type I, mild, common, with blue sclera; OI type II, perinatal lethal form; OI type III, severe and progressively deforming, with normal sclera; and OI type IV, moderate severity with normal sclera. Approximately 90% of individuals with OI are heterozygous for mutations in the COL1A1 and COL1A2 genes, with dominant pattern of inheritance or sporadic mutations. After 2006, mutations were identified in the CRTAP, FKBP10, LEPRE1, PLOD2, PPIB, SERPINF1, SERPINH1, SP7, WNT1, BMP1, and TMEM38B genes, associated with recessive OI and mutation in the IFITM5 gene associated with dominant OI. Mutations in PLS3 were recently identified in families with osteoporosis and fractures, with X-linked inheritance pattern. In addition to the genetic complexity of the molecular basis of OI, extensive phenotypic variability resulting from individual loci has also been documented. CONCLUSIONS: Considering the discovery of new genes and limited genotype-phenotype correlation, the use of next-generation sequencing tools has become useful in molecular studies of OI cases. The recommendation of the Nosology Group of the International Society of Skeletal Dysplasias is to maintain the classification of Sillence as the prototypical form, universally accepted to classify the degree of severity in OI, while maintaining it free from direct molecular reference.

Objective: Literature review of new genes related to osteogenesis imperfecta (OI) and update of its classification. Sources: Literature review in the PubMed and OMIM databases, followed by selection of relevant references. Summary of the findings: In 1979, Sillence et al. developed a classification of OI subtypes based on clinical features and disease severity: OI type I, mild, common, with blue sclera; OI type II, perinatal lethal form; OI type III, severe and progressively deforming, with normal sclera; and OI type IV, moderate severity with normal sclera. Approximately 90% of individuals with OI are heterozygous for mutations in the COL1A1 and COL1A2 genes, with dominant pattern of inheritance or sporadic mutations. After 2006, mutations were identified in the CRTAP, FKBP10, LEPRE1, PLOD2, PPIB, SERPINF1, SERPINH1, SP7, WNT1, BMP1, and TMEM38B genes, associated with recessive OI and mutation in the IFITM5 gene associated with dominant OI. Mutations in PLS3 were recently identified in families with osteoporosis and fractures, with X-linked inheritance pattern. In addition to the genetic complexity of the molecular basis of OI, extensive phenotypic variability resulting from individual loci has also been documented. Conclusions: Considering the discovery of new genes and limited genotype-phenotype correlation, the use of next-generation sequencing tools has become useful in molecular studies of OI cases. The recommendation of the Nosology Group of the International Society of Skeletal Dysplasias is to maintain the classification of Sillence as the prototypical form, universally accepted to classify the degree of severity in OI, while maintaining it free from direct molecular reference. Resumo: Objetivo: Revisão da literatura sobre novos genes relacionados à osteogênese imperfeita (OI) e atualização da sua classificação. Fonte dos dados: Revisão nas bases de dados do PUBMED e OMIM com seleção de referências relevantes. Síntese dos dados: Sillence et al., em 1979, desenvolveram uma classificação dos subtipos de OI baseada em características clínicas e gravidade da doença: OI tipo I, forma leve, comum, com escleras azuladas; OI tipo II, forma perinatal letal; OI tipo III, forma grave e progressivamente deformante com esclera normal; e OI tipo IV, forma de gravidade moderada com esclera normal. Cerca de 90% dos indivíduos com OI são heterozigotos para mutações em COL1A1 e COL1A2, com padrão de herança dominante ou esporádico. A partir de 2006 foram identificadas mutações nos genes CRTAP, FKBP10, LEPRE1, PLOD2, PPIB, SERPINF1, SERPINH1, SP7, WNT1, BMP1 e TMEM38B associadas à OI recessiva e mutação em IFITM5 associada à OI dominante. Mutações em PLS3 foram identificadas recentemente em famílias com osteoporose e fraturas, com padrão de herança ligado ao X. Além da complexidade genética das bases moleculares das OI, extensa variabilidade fenotípica resultante de loci individuais também tem sido documentada. Conclusões: Face à descoberta de novos genes e à correlação genótipo-fenótipo limitada, o uso de ferramentas de sequenciamento de nova geração torna-se útil no estudo molecular de casos de OI. A recomendação do Grupo de Nosologia da Sociedade Internacional de Displasias Esqueléticas é manter a classificação de Sillence como a forma prototípica e universalmente aceita para classificar o grau de gravidade na OI, e libertá-la de referência molecular direta. Keywords: Osteogenesis imperfecta, Osteochondrodysplasias, Collagen type 1, Palavras-chave: Osteogênese imperfeita, Osteocondrodisplasias, Colágeno tipo 1

Objective: Literature review of new genes related to osteogenesis imperfecta (OI) and update of its classification. Sources: Literature review in the PubMed and OMIM databases, followed by selection of relevant references. Summary of the findings: In 1979, Sillence et al. developed a classification of OI subtypes based on clinical features and disease severity: OI type I, mild, common, with blue sclera; OI type II, perinatal lethal form; OI type III, severe and progressively deforming, with normal sclera; and OI type IV, moderate severity with normal sclera. Approximately 90% of individuals with OI are heterozygous for mutations in the COL1A1 and COL1A2 genes, with dominant pattern of inheritance or sporadic mutations. After 2006, mutations were identified in the CRTAP, FKBP10, LEPRE1, PLOD2, PPIB, SERPINF1, SERPINH1, SP7, WNT1, BMP1, and TMEM38B genes, associated with recessive OI and mutation in the IFITM5 gene associated with dominant OI. Mutations in PLS3 were recently identified in families with osteoporosis and fractures, with X‐linked inheritance pattern. In addition to the genetic complexity of the molecular basis of OI, extensive phenotypic variability resulting from individual loci has also been documented. Conclusions: Considering the discovery of new genes and limited genotype‐phenotype correlation, the use of next‐generation sequencing tools has become useful in molecular studies of OI cases. The recommendation of the Nosology Group of the International Society of Skeletal Dysplasias is to maintain the classification of Sillence as the prototypical form, universally accepted to classify the degree of severity in OI, while maintaining it free from direct molecular reference.

ABSTRACT Introduction: The high performance liquid chromatography is a technique used for quantification of amino acids in plasma. The definition of reference intervals in the population is very important for the diagnosis and monitoring of individuals with amino acid disorders. Objectives: The objectives of this study were to validate a method for amino acids quantification and define reference intervals in Brazilian children. Results: Good chromatographic separation was achieved using C18 solid-core column. The method showed satisfactory linearity, limits of detection and quantification, precision and accuracy. The reference ranges for aspartate, glutamate, asparagine, histidine, serine, glutamine, arginine, tyrosine, alanine, tryptophan, methionine, valine, phenylalanine, isoleucine and leucine were defined in a group of 60 healthy individuals aged 2 to 14 years. Conclusion: The presented technique can be applied in clinical practice. Each laboratory should preferably establish its own reference intervals. If that is not possible, it is recommended the use of the reference intervals described in this study for the diagnosis and monitoring of Brazilian children in this age group.

Introduction: Although the diurnal fluctuation of motor dysfunction, reversible with small doses of dopamine, is a cornerstone for the phenotype of the autosomal dominant Segawa syndrome, the non-motor symptoms of this neurotransmitter deficiency have still received limited attention. Objective: This study aims to evaluate non-motor symptoms of this dopa-responsive dystonia through an intrafamilial comparative cross-sectional study. Methods: Seventeen individuals with a c.IVS5 + 3insT (c.626 + 3insT) variation in the GTP cyclohydrolase-1 gene (GCH1, HGNC: 4193) and 34 intrafamilial controls were studied using the Beck Depression Inventory-II, the Wiener Matrizen Test 2, the Epworth Sleepiness Scale, the Pittsburgh Sleep Quality Index, the MINI/MINI PLUS Questionnaires, the World Health Organization Quality of Life – BREF Instrument and a drug use assessment questionnaire. Results: No significant difference was found between the groups in the prevalence of sleep disorders and in cognitive function. Nevertheless, generalized anxiety disorder (p = 0.050) and attention-deficit/hyperactivity disorder in childhood (p = 0.011) were observed only in individuals without the molecular variation. The group with the GCH1 variation presented a worse perception about how safe they feel in their daily lives (p = 0.034), less satisfaction with themselves (p = 0.049) and with their relationships (p = 0.029), and a higher prevalence of past major depressive episodes before use of L-Dopa (p = 0.046). Conclusion: Low dopamine could have been protective against generalized anxiety disorder and attention-deficit/hyperactivity disorder in childhood in Segawa group individuals. The prevalence of depression was higher in individuals with the molecular variant prior to the L-Dopa treatment. Considering it, the penetrance estimates for the variant carriers increased from 58.8% to up to 88% in this large studied family. Additionally, neuropsychiatric tests of all individuals with a molecular diagnosis in an affected family are a valuable instrument for its clinical management.

A doença de Gaucher (DG) é um erro inato do metabolismo do grupo das doenças lisossômicas de depósito, sendo a mais freqüente do referido grupo. É de herança autossômica recessiva, portanto com risco de 25% a cada gestação de casal heterozigoto. A doença é resultante da deficiência da beta-glicosidase ácida ou beta-glicocerebrosidase, que leva ao acúmulo de glicolipídios nos macrófagos principalmente em baço, fígado, medula óssea e pulmão. As manifestações clínicas ou fenotípicas da DG vão depender do grau de deficiência da enzima, existindo três tipos: Tipo I, forma não neuropática, afeta crianças e adultos com hepatoesplenomegalia, anemia, trombocitopenia, leucopenia e lesões ósseas; Tipo II, forma neuropática aguda, afeta crianças com 4-5 meses com quadro neurológico grave, hepatoesplenomegalia e comprometimento pulmonar e o Tipo III, forma neuropática crônica, afeta crianças e adolescentes com quadro neurológico menos grave que o Tipo II e ainda pode comprometer fígado, baço e ossos. Um grupo de catorze médicos com experiência no tratamento da DG com reposição enzimática realizaram extensa revisão da literatura, confrontaram com os dados evolutivos dos pacientes brasileiros e chegaram a um consenso quanto aos critérios para iniciar o tratamento, a dose da enzima e freqüência das infusões, do acompanhamento ambulatorial, laboratorial e radiológico. O Grupo Brasileiro de Estudos em Doença de Gaucher e outras Doenças de Depósito Lisossômico (GBDDL) tem o objetivo de estabelecer diretrizes para o diagnostico, tratamento e acompanhamento de pacientes com doença de Gaucher no Brasil. Esta iniciativa pioneira visa uniformizar a conduta no país com relação ao tratamento de DG com reposição enzimática, tratamento de alto custo porém de grande eficácia.