title: A large-scale survey of genetic copy number variations among Han Chinese residing in Taiwan.
abstract: BACKGROUND
  Copy number variations (CNVs) have recently been recognized as important structural variations in the human genome. CNVs can affect gene expression and thus may contribute to phenotypic differences. The copy number inferring tool (CNIT) is an effective hidden Markov model-based algorithm for estimating allele-specific copy number and predicting chromosomal alterations from single nucleotide polymorphism microarrays. The CNIT algorithm, which was constructed using data from 270 HapMap multi-ethnic individuals, was applied to identify CNVs from 300 unrelated Han Chinese individuals in Taiwan.
  
  
  RESULTS
  Using stringent selection criteria, 230 regions with variable copy numbers were identified in the Han Chinese population; 133 (57.83%) had been reported previously, 64 displayed greater than 1% CNV allele frequency. The average size of the CNV regions was 322 kb (ranging from 1.48 kb to 5.68 Mb) and covered a total of 2.47% of the human genome. A total of 196 of the CNV regions were simple deletions and 27 were simple amplifications. There were 449 genes and 5 microRNAs within these CNV regions; some of these genes are known to be associated with diseases.
  
  
  CONCLUSIONS
  The identified CNVs are characteristic of the Han Chinese population and should be considered when genetic studies are conducted. The CNV distribution in the human genome is still poorly characterized, and there is much diversity among different ethnic populations.
authors.affiliation: Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan. eviliori.tw@yahoo.com.tw
authors.forename: Chien-Hsing
authors.initials: CH
authors.lastname: Lin
authors.forename: Ling-Hui
authors.initials: LH
authors.lastname: Li
authors.forename: Sheng-Feng
authors.initials: SF
authors.lastname: Ho
authors.forename: Tzu-Po
authors.initials: TP
authors.lastname: Chuang
authors.forename: Jer-Yuarn
authors.initials: JY
authors.lastname: Wu
authors.forename: Yuan-Tsong
authors.initials: YT
authors.lastname: Chen
authors.forename: Cathy S J
authors.initials: CS
authors.lastname: Fann
mesh_terms: D000465:Algorithms; D000483:Alleles; D044466:Asian People / Q000235:genetics*; D018628:Gene Dosage; D005787:Gene Frequency; D005828:Genetics, Population; D015894:Genome, Human; D006801:Humans; D008390:Markov Chains; D035683:MicroRNAs / Q000235:genetics; D008957:Models, Genetic; D020411:Oligonucleotide Array Sequence Analysis; D020641:Polymorphism, Single Nucleotide; D012984:Software; D013624:Taiwan
chemical_list: D035683:MicroRNAs