Oligonucleotide microarray analysis of genomic imbalance in children with mental retardation

J. M. Friedman, Ágnes Baross, Allen D. Delaney, Adrian Ally, Laura Arbour, Jennifer Asano, Dione K. Bailey, Sarah Barber, Patricia Birch, Mabel Brown-John, Manqiu Cao, Susanna Chan, David L. Charest, Noushin Farnoud, Nicole Fernandes, Stephane Flibotte, Anne Go, William T. Gibson, Robert A. Holt, Steven J M JonesGiulia C. Kennedy, Martin Krzywinski, Sylvie Langlois, Haiyan I. Li, Barbara C. McGillivray, Tarun Nayar, Trevor J. Pugh, Evica Rajcan-Separovic, Jacqueline E. Schein, Angelique Schnerch, Asim Siddiqui, Margot I. Van Allen, Gary Wilson, Siu Li Yong, Farah Zahir, Patrice Eydoux, Marco A. Marra

Research output: Contribution to journalArticle

223 Citations (Scopus)


The cause of mental retardation in one-third to one-half of all affected individuals is unknown. Microscopically detectable chromosomal abnormalities are the most frequently recognized cause, but gain or loss of chromosomal segments that are too small to be seen by conventional cytogenetic analysis has been found to be another important cause. Array-based methods offer a practical means of performing a high-resolution survey of the entire genome for submicroscopic copy-number variants. We studied 100 children with idiopathic mental retardation and normal results of standard chromosomal analysis, by use of whole-genome sampling analysis with Affymetrix GeneChip Human Mapping 100K arrays. We found de novo deletions as small as 178 kb in eight cases, de novo duplications as small as 1.1 Mb in two cases, and unsuspected mosaic trisomy 9 in another case. This technology can detect at least twice as many potentially pathogenic de novo copy-number variants as conventional cytogenetic analysis can in people with mental retardation.

Original languageEnglish
Pages (from-to)500-513
Number of pages14
JournalAmerican Journal of Human Genetics
Issue number3
Publication statusPublished - Sep 2006
Externally publishedYes


ASJC Scopus subject areas

  • Genetics
  • Genetics(clinical)

Cite this

Friedman, J. M., Baross, Á., Delaney, A. D., Ally, A., Arbour, L., Asano, J., Bailey, D. K., Barber, S., Birch, P., Brown-John, M., Cao, M., Chan, S., Charest, D. L., Farnoud, N., Fernandes, N., Flibotte, S., Go, A., Gibson, W. T., Holt, R. A., ... Marra, M. A. (2006). Oligonucleotide microarray analysis of genomic imbalance in children with mental retardation. American Journal of Human Genetics, 79(3), 500-513. https://doi.org/10.1086/507471