Identification of disease genes by whole genome CGH arrays.
Small, submicroscopic, genomic deletions and duplications (1 kb to 10 Mb) constitute up to 15% of all mutations underlying human monogenic diseases. Novel genomic technologies such as microarray-based comparative genomic hybridization (array CGH) allow the mapping of genomic copy number alterations at this submicroscopic level, thereby directly linking disease phenotypes to gene dosage alterations. At present, the entire human genome can be scanned for deletions and duplications at over 30,000 loci simultaneously by array CGH ( approximately 100 kb resolution), thus entailing an attractive gene discovery approach for monogenic conditions, in particular those that are associated with reproductive lethality. Here, we review the present and future potential of microarray-based mapping of genes underlying monogenic diseases and discuss our own experience with the identification of the gene for CHARGE syndrome. We expect that, ultimately, genomic copy number scanning of all 250,000 exons in the human genome will enable immediate disease gene discovery in cases exhibiting single exon duplications and/or deletions.
Vissers
Lisenka E L M
LE
Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, PO Box 9101 6500 HB Nijmegen, The Netherlands.
Veltman
Joris A
JA
van Kessel
Ad Geurts
AG
Brunner
Han G
HG
D018628:Gene Dosage; D020869:Gene Expression Profiling / Q000379:methods; D030342:Genetic Diseases, Inborn / Q000235:genetics*; D015894:Genome, Human; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping / Q000379:methods; D046228:Microarray Analysis / Q000379:methods*