title: [Genetic diagnosis and analysis for two cases of ring chromosome 22].
abstract: OBJECTIVE
  To confirm the genetic diagnosis of two patients with ring chromosome 22 syndrome and investigate the mechanism underlying the formation of r(22) and potential genetic causes for the clinical phenotypes.
  
  
  METHODS
  Cytogenetic and molecular analyses using standard G-banding, fluorescence in situ hybridization and single nucleotide polymorphism array (SNP array) were performed.
  
  
  RESULTS
  For case 1, the karyotype was 46,XY,r(22)(p11q13). SNP array has identified a 7.0 Mb heterozygous deletion at 22q13.2q13.33. For case 2, the karyotype was 46,XY,r(22)(p11q13)[84]/45,XY,-22[6]; SNP array has detected a heterozygous microdeletion of 1.6 Mb at 22q13.33.
  
  
  CONCLUSIONS
  With combined application of genetic testing, 2 cases of r(22) syndrome were diagnosed, which has improved the understanding of the genotype-phenotype correlation of r(22).
authors.affiliation: State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan 410078, China. Email: wulingqian@sklmg.edu.cn.
authors.forename: Ying
authors.initials: Y
authors.lastname: Peng
authors.forename: Guizhi
authors.initials: G
authors.lastname: Tang
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.forename: Yanghui
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yan
authors.initials: Y
authors.lastname: Xia
authors.forename: Ruiyu
authors.initials: R
authors.lastname: Ma
authors.forename: Ruolan
authors.initials: R
authors.lastname: Guo
authors.forename: Lingqian
authors.initials: L
authors.lastname: Wu
mesh_terms: D002675:Child, Preschool; D002871:Chromosome Banding; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics; D005820:Genetic Testing; D006801:Humans; D008297:Male; D009419:Nerve Tissue Proteins / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D020641:Polymorphism, Single Nucleotide; D012303:Ring Chromosomes
chemical_list: D009419:Nerve Tissue Proteins; C492357:SHANK3 protein, human