Medicine and Health Sciences Commons^™

The Clinical Impact Of Copy Number Variants In Inherited Bone Marrow Failure Syndromes, Nicolas Waespe, Santhosh Dhanraj, Manju Wahala, Elena Tsangaris, Tom Enbar, Bozana Zlateska, Hongbing Li, Robert J Klaassen, Conrad V Fernandez, Geoff D E Cuvelier, John K Wu, Yves D Pastore, Mariana Silva, Jeffrey H Lipton, Joseé Brossard, Bruno Michon, Sharon Abish, Macgregor Steele, Roona Sinha, Mark J Belletrutti, Vicky R Breakey, Lawrence Jardine, Lisa Goodyear, Liat Kofler, Michaela Cada, Lillian Sung, Mary Shago, Stephen W Scherer, Yigal Dror

Paediatrics Publications

Inherited bone marrow failure syndromes (IBMFSs) comprise a genetically heterogeneous group of diseases with hematopoietic failure and a wide array of physical malformations. Copy number variants (CNVs) were reported in some IBMFSs. It is unclear what impact CNVs play in patients evaluated for a suspected diagnosis of IBMFS. Clinical and genetic data of 323 patients from the Canadian Inherited Marrow Failure Registry from 2001 to 2014, who had a documented genetic work-up, were analyzed. Cases with pathogenic CNVs (at least 1 kilobasepairs) were compared to cases with other mutations. Genotype-phenotype correlations were performed to assess the impact of CNVs. Pathogenic …

Identification Of Epigenetic Signature Associated With Alpha Thalassemia/Mental Retardation X-Linked Syndrome, Laila C Schenkel, Kristin D Kernohan, Arran Mcbride, Ditta Reina, Amanda Hodge, Peter J Ainsworth, David I Rodenhiser, Guillaume Pare, Nathalie G Bérubé, Cindy Skinner, Kym M Boycott, Charles Schwartz, Bekim Sadikovic

Paediatrics Publications

BACKGROUND: Alpha thalassemia/mental retardation X-linked syndrome (ATR-X) is caused by a mutation at the chromatin regulator gene

RESULTS: We performed genome-wide DNA methylation assessment of the peripheral blood samples from 18 patients with ATR-X and compared it to 210 controls. We demonstrated the evidence of a unique and highly specific DNA methylation "epi-signature" in the peripheral blood of ATRX patients, which was corroborated by targeted bisulfite sequencing experiments. Although genomically represented, differentially methylated regions showed evidence of preferential clustering in pericentromeric and telometric chromosomal regions, areas where ATRX has multiple functions related to maintenance of heterochromatin and genomic integrity.

CONCLUSION: …

Molecular Characterization Of Nrxn1 Deletions From 19,263 Clinical Microarray Cases Identifies Exons Important For Neurodevelopmental Disease Expression, Chelsea Lowther, Marsha Speevak, Christine M Armour, Elaine S Goh, Gail E Graham, Chumei Li, Susan Zeesman, Malgorzata J M Nowaczyk, Lee-Anne Schultz, Antonella Morra, Rob Nicolson, Peter Bikangaga, Dawa Samdup, Mostafa Zaazou, Kerry Boyd, Jack H Jung, Victoria Siu, Manjulata Rajguru, Sharan Goobie, Mark A Tarnopolsky, Chitra Prasad, Paul T Dick, Asmaa S Hussain, Margreet Walinga, Renske G Reijenga, Matthew Gazzellone, Anath C Lionel, Christian R Marshall, Stephen W Scherer, Dimitri J Stavropoulos, Elizabeth Mccready, Anne S Bassett

Paediatrics Publications

PURPOSE: The purpose of the current study was to assess the penetrance of NRXN1 deletions.

METHODS: We compared the prevalence and genomic extent of NRXN1 deletions identified among 19,263 clinically referred cases to that of 15,264 controls. The burden of additional clinically relevant copy-number variations (CNVs) was used as a proxy to estimate the relative penetrance of NRXN1 deletions.

RESULTS: We identified 41 (0.21%) previously unreported exonic NRXN1 deletions ascertained for developmental delay/intellectual disability that were significantly greater than in controls (odds ratio (OR) = 8.14; 95% confidence interval (CI): 2.91-22.72; P < 0.0001). Ten (22.7%) of these had a second clinically relevant CNV. Subjects with a deletion near the 3' end of NRXN1 were significantly more likely to have a second rare CNV than subjects with a 5' NRXN1 deletion (OR = 7.47; 95% CI: 2.36-23.61; P = 0.0006). The prevalence of intronic NRXN1 deletions was not statistically different between cases and controls (P = 0.618). The majority (63.2%) of intronic NRXN1 deletion cases had a second rare CNV at a prevalence twice as high as that for exonic NRXN1 deletion cases (P = 0.0035).

CONCLUSIONS: The results support the importance of exons …