RESUMO
Interpretation of variants of uncertain significance, especially chromosomal rearrangements in non-coding regions of the human genome, remains one of the biggest challenges in modern molecular diagnosis. To improve our understanding and interpretation of such variants, we used high-resolution three-dimensional chromosomal structural data and transcriptional regulatory information to predict position effects and their association with pathogenic phenotypes in 17 subjects with apparently balanced chromosomal abnormalities. We found that the rearrangements predict disruption of long-range chromatin interactions between several enhancers and genes whose annotated clinical features are strongly associated with the subjects' phenotypes. We confirm gene-expression changes for a couple of candidate genes to exemplify the utility of our analysis of position effect. These results highlight the important interplay between chromosomal structure and disease and demonstrate the need to utilize chromatin conformational data for the prediction of position effects in the clinical interpretation of non-coding chromosomal rearrangements.
Assuntos
Efeitos da Posição Cromossômica/genética , Mapeamento Cromossômico , Cromossomos Humanos/genética , Rearranjo Gênico/genética , Predisposição Genética para Doença/genética , Genoma Humano/genética , Pontos de Quebra do Cromossomo , Regulação da Expressão Gênica/genética , Variação Genética/genética , Humanos , Hibridização in Situ Fluorescente , Cariótipo , Fenótipo , Translocação Genética/genéticaRESUMO
The COMT gene is thought to contribute to the cognitive/psychiatric phenotypes in 22q11.2 deletion syndrome. We measured these manifestations against the Val/Met alleles of the COMT gene, in 40 nonpsychotic 22q11DS children. The Val allele was associated with poor IQ, processing speed, executive function and a higher frequency of anxiety disorders, underscoring the importance of the COMT gene in the childhood psychopathology in 22q11DS.
Assuntos
Ansiedade/genética , Catecol O-Metiltransferase/genética , Transtornos Cognitivos/genética , Síndrome de DiGeorge/genética , Predisposição Genética para Doença , Adolescente , Criança , Função Executiva/fisiologia , Feminino , Genótipo , Humanos , Masculino , Metionina/genética , Testes Neuropsicológicos , Polimorfismo de Nucleotídeo Único , Escalas de Graduação Psiquiátrica , Valina/genéticaRESUMO
Recurrent deletions of 2q32q33 have recently been reported as a new microdeletion syndrome. Clinical features of this syndrome include severe mental retardation, growth retardation, dysmorphic features, thin and sparse hair, feeding difficulties and cleft or high palate. The commonly deleted region contains at least seven genes. Haploinsufficiency of one of these genes, SATB2, a DNA-binding protein that regulates gene expression, has been implicated as causative in the cleft or high palate of individuals with 2q32q33 microdeletion syndrome. In this study we describe three individuals with smaller microdeletions of this region, within 2q33.1. The deletions ranged in size from 173.1 kb to 185.2 kb and spanned part of SATB2. Review of clinical records showed similar clinical features among these individuals, including severe developmental delay and tooth abnormalities. Two of the individuals had behavioral problems. Only one of the subjects presented here had a cleft palate, suggesting reduced penetrance for this feature. Our results suggest that deletion of SATB2 is responsible for several of the clinical features associated with 2q32q33 microdeletion syndrome.
