title: [Analysis of gross deletions of COL1A1/2 genes in Chinese families affected with osteogenesis imperfecta].
abstract: OBJECTIVE
  To identify deletion of large fragment in COL1A1/2 genes among patients with osteogenesis imperfecta (OI).
  
  
  METHODS
  Genomic DNA was extracted from peripheral blood samples by a standard SDS-proteinase K-phenol/chloroform method. Multiplex ligation-dependent probe amplification (MLPA) was performed to detect gross deletions of the COL1A1/2 genes among 46 patients affected with OI, in whom no mutation was detected in the sequences of the COL1A1/2 genes.
  
  
  RESULTS
  Heterozygous deletions of the entire COL1A1 gene and exon 20 of the COL1A2 gene were detected in probands A and B, respectively, and no gross deletion was found in the remaining 44 samples. The MLPA result of proband A was confirmed by fluorescence quantitative PCR (Q-PCR) in his family. A further conjunction point analysis through gap-PCR and DNA sequencing revealed deletion of exons 17 to 23 in the COL1A2 gene, and a 637 bp-insertion from chromosome 5 in the proband B.
  
  
  CONCLUSIONS
  Two gross deletions have been found in the genes coding for collagen type I in the Chinese OI population, and the deletion of exons 17 to 23 in the COL1A2 gene is a novel mutation. This work not only has expanded the mutation spectrum of the COL1A1/2 gene, but also provided a support for prenatal genetic diagnosis for the families.
authors.affiliation: Department of Medical Genetics and National Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing 100005, China; The People's Hospital of Wuqing, Tianjin 301700, China. Email: xiulizhao@ibms.pumc.edu.cn.
authors.forename: Han
authors.initials: H
authors.lastname: Wang
authors.forename: Xiuli
authors.initials: X
authors.lastname: Zhao
authors.forename: Xiuzhi
authors.initials: X
authors.lastname: Ren
authors.forename: Jifang
authors.initials: J
authors.lastname: Xiao
authors.forename: Xue
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D024042:Collagen Type I / Q000235:genetics*; D000090602:Collagen Type I, alpha 1 Chain; D005260:Female; D017353:Gene Deletion; D006801:Humans; D008297:Male; D008875:Middle Aged; D060885:Multiplex Polymerase Chain Reaction; D010013:Osteogenesis Imperfecta / Q000235:genetics*
chemical_list: C000601279:COL1A2 protein, human; D024042:Collagen Type I; D000090602:Collagen Type I, alpha 1 Chain