Project description:This study includes the whole-genome screening of unbalanced chromosomal rearrangements (copy-number variants; CNV) in children with ID/DD, ASD and MCA. We identified a broad range of pathogenic/likely pathogenic CNVs as well as variants of unclear significance and likely benign variants. Our results confirm the benefit of array-CGH in the current clinical genetic diagnostics through the identification of genetic cause of ID/DD in the high proportion of affected children.
Project description:This study includes the whole-genome screening of unbalanced chromosomal rearrangements (copy-number variants; CNV) in children with ID/DD, ASD and MCA. We identified a broad range of pathogenic/likely pathogenic CNVs as well as variants of unclear significance and likely benign variants. Our results confirm the benefit of array-CGH in the current clinical genetic diagnostics through the identification of genetic cause of ID/DD in the high proportion of affected children.
Project description:This study includes the whole-genome screening of unbalanced chromosomal rearrangements (copy-number variants; CNV) in children with ID/DD, ASD and MCA. We identified a broad range of pathogenic/likely pathogenic CNVs as well as variants of unclear significance and likely benign variants. Our results confirm the benefit of array-CGH in the current clinical genetic diagnostics through the identification of genetic cause of ID/DD in the high proportion of affected children.
Project description:This study includes the whole-genome screening of unbalanced chromosomal rearrangements (copy-number variants; CNV) in children with ID/DD, ASD and MCA. We identified a broad range of pathogenic/likely pathogenic CNVs as well as variants of unclear significance and likely benign variants. Our results confirm the benefit of array-CGH in the current clinical genetic diagnostics through the identification of genetic cause of ID/DD in the high proportion of affected children.
Project description:This study includes the whole-genome screening of unbalanced chromosomal rearrangements (copy-number variants; CNV) in children with ID/DD, ASD and MCA. We identified a broad range of pathogenic/likely pathogenic CNVs as well as variants of unclear significance and likely benign variants. Our results confirm the benefit of array-CGH in the current clinical genetic diagnostics through the identification of genetic cause of ID/DD in the high proportion of affected children.
Project description:This study includes the whole-genome screening of unbalanced chromosomal rearrangements (copy-number variants; CNV) in children with ID/DD, ASD and MCA. We identified a broad range of pathogenic/likely pathogenic CNVs as well as variants of unclear significance and likely benign variants. Our results confirm the benefit of array-CGH in the current clinical genetic diagnostics through the identification of genetic cause of ID/DD in the high proportion of affected children.
Project description:This study includes the whole-genome screening of unbalanced chromosomal rearrangements (copy-number variants; CNV) in children with ID/DD, ASD and MCA. We identified a broad range of pathogenic/likely pathogenic CNVs as well as variants of unclear significance and likely benign variants. Our results confirm the benefit of array-CGH in the current clinical genetic diagnostics through the identification of genetic cause of ID/DD in the high proportion of affected children.
Project description:Products of conception that were diagnosed either euploid or aneuploid during routine cytogenetic analysis were analysed by a novel CGH+SNP array for the evaluation of its usefulness in clinical diagnostics.
Project description:Gene amplifications and deletions frequently contribute to tumorigenesis. Characterization of these DNA copy-number changes is important for both the basic understanding of cancer and its diagnosis. Comparative genomic hybridization (CGH) was developed to survey DNA copy-number variations across a whole genome. With CGH, differentially labelled test and reference genomic DNAs are co-hybridized to normal metaphase chromosomes, and fluorescence ratios along the length of chromosomes provide a cytogenetic representation of DNA copy-number variation. CGH, however, has a limited ( approximately 20 Mb) mapping resolution, and higher-resolution techniques, such as fluorescence in situ hybridization (FISH), are prohibitively labour-intensive on a genomic scale. Array-based CGH, in which fluorescence ratios at arrayed DNA elements provide a locus-by-locus measure of DNA copy-number variation, represents another means of achieving increased mapping resolution. Published array CGH methods have relied on large genomic clone (for example BAC) array targets and have covered only a small fraction of the human genome. cDNAs representing over 30,000 radiation-hybrid (RH)-mapped human genes provide an alternative and readily available genomic resource for mapping DNA copy-number changes. Although cDNA microarrays have been used extensively to characterize variation in human gene expression, human genomic DNA is a far more complex mixture than the mRNA representation of human cells. Therefore, analysis of DNA copy-number variation using cDNA microarrays would require a sensitivity of detection an order of magnitude greater than has been routinely reported. We describe here a cDNA microarray-based CGH method, and its application to DNA copy-number variation analysis in breast cancer cell lines and tumours. This study is described more fully in Pollack JR et al.(1999) Nat Genet 23:41-6 Keywords: other
Project description:Insertions occur when a segment of one chromosome is translocated and inserted into a new region of the same chromosome or a non-homologous chromosome. We report 69 cases with unbalanced insertions identified using array CGH and FISH, representing 1.25% of 5,683 cases referred to our laboratory for array CGH and found to have copy-number abnormalities. Although the majority of insertions were non-recurrent, several recurrent unbalanced insertions were detected, including three der(Y)ins(Y;18)(q?11.2;p11.32p11.32)pat inherited from parents carrying an unbalanced insertion. The clinical significance of these recurrent rearrangements is unclear, although the small size, limited gene content, and inheritance pattern of each suggests the phenotypic consequences may be benign. Moreover, cryptic, submicroscopic duplications were observed at or near the insertion sites in two patients, further confounding the clinical interpretation of these insertions. Using FISH, linear amplification and array CGH we identified a 126-kb duplicated region from 19p13.3 inserted into MECP2 at Xq28 in a patient with symptoms of Rett syndrome. Our results demonstrate that although the interpretation of most non-recurrent insertions is unclear without high-resolution insertion site characterization, the potential for an otherwise benign duplication to result in a clinically relevant outcome through the disruption of a gene necessitates the use of FISH to determine whether copy-number gains detected by array CGH represent tandem duplications or unbalanced insertions. Further follow-up testing using techniques such as linear amplification coupled with array CGH or sequencing should be used to determine gene involvement at the insertion site after FISH has identified the presence of an insertion.