title: Breakpoints and deleted genes identification of ring chromosome 18 in a Chinese girl by whole-genome low-coverage sequencing: a case report study.
abstract: BACKGROUND
  Ring chromosome 18 [r(18)] is formed by 18p- and 18q- partial deletion and generates a ring chromosome. Loss of critical genes on each arm of chromosome 18 may contribute to the specific phenotype, and the clinical spectrum varieties may heavily depend on the extent of the genomic deletion. The aim of this study is to identify the detailed breakpoints location and the deleted genes result from the r18.
  
  
  METHODS
  Here we describe a detailed diagnosis of a seven-year-old Chinese girl with a ring chromosome 18 mutation by a high-throughput whole-genome low-coverage sequencing approach without karyotyping and other cytogenetic analysis. This method revealed two fragment heterozygous deletions of 18p and 18q, and further localized the detailed breakpoint sites and fusion, as well as the deleted genes.
  
  
  CONCLUSIONS
  To our knowledge, this is the first report of a ring chromosome 18 patient in China analyzed by whole-genome low-coverage sequencing approach. Detailed breakpoints location and deleted genes identification help to estimate the risk of the disease in the future. The data and analysis here demonstrated the feasibility of next-generation sequencing technologies for chromosome structure variation including ring chromosome in an efficient and cost effective way.
authors.affiliation: Wuhan Medical Care Center for Women and Children, Wuhan, 430015, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Yao
authors.affiliation: BGI-Shenzhen, Shenzhen, 518083, China.
authors.forename: Chuanchun
authors.initials: C
authors.lastname: Yang
authors.affiliation: Wuhan Medical Care Center for Women and Children, Wuhan, 430015, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Huang
authors.affiliation: Wuhan Medical Care Center for Women and Children, Wuhan, 430015, China.
authors.forename: Luhong
authors.initials: L
authors.lastname: Yang
authors.affiliation: BGI-Wuhan, Wuhan, 430075, China.|BGI-Shenzhen, Shenzhen, 518083, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.affiliation: BGI-Wuhan, Wuhan, 430075, China.|BGI-Shenzhen, Shenzhen, 518083, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Yin
authors.affiliation: Wuhan Medical Care Center for Women and Children, Wuhan, 430015, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Qin
authors.affiliation: BGI-Wuhan, Wuhan, 430075, China.|BGI-Shenzhen, Shenzhen, 518083, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Mu
authors.affiliation: BGI-Wuhan, Wuhan, 430075, China.|BGI-Shenzhen, Shenzhen, 518083, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Liu
authors.affiliation: Wuhan Medical Care Center for Women and Children, Wuhan, 430015, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Tian
authors.affiliation: Wuhan Medical Care Center for Women and Children, Wuhan, 430015, China.
authors.forename: Zhisheng
authors.initials: Z
authors.lastname: Liu
authors.affiliation: BGI-Wuhan, Wuhan, 430075, China. @genomics.cn.|BGI-Shenzhen, Shenzhen, 518083, China. @genomics.cn.|Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China. @genomics.cn.
authors.forename: Yun
authors.initials: Y
authors.lastname: Yang
mesh_terms: D002648:Child; D002681:China; D002887:Chromosomes, Human, Pair 18; D020732:Cytogenetic Analysis; D005260:Female; D017353:Gene Deletion; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D059785:Karyotype; D008279:Magnetic Resonance Imaging; D010641:Phenotype; D010902:Pituitary Gland / Q000000981:diagnostic imaging; D012303:Ring Chromosomes; D017422:Sequence Analysis, DNA
keywords: Detailed breakpoints; Detailed diagnosis; Ring chromosome; Whole-genome low-coverage sequencing