title: [Analysis of genetics mechanism for the phenotypic diversity in a patient carrying a rare ring chromosome 9].
abstract: OBJECTIVE
  To explore the genetics mechanism for the phenotypic variability in a patient carrying a rare ring chromosome 9.
  
  
  METHODS
  The karyotype of the patient was analyzed with cytogenetics method. Presence of sex chromosome was confirmed with fluorescence in situ hybridization. The SRY gene was subjected to PCR amplification and direct sequencing. Potential deletion and duplication were detected with array-based comparative genomic hybridization (array-CGH).
  
  
  RESULTS
  The karyotype of the patient has comprised 6 types of cell lines containing a ring chromosome 9. The SRY gene sequence was normal. By array-CGH, the patient has carried a hemizygous deletion at 9p24.3-p23 (174 201-9 721 761) encompassing 30 genes from Online Mendelian Inheritance in Man.
  
  
  CONCLUSIONS
  The phenotypic variability of the 9p deletion syndrome in conjunct with ring chromosome 9 may be attributable to multiple factors including loss of chromosomal material, insufficient dosage of genes, instability of ring chromosome, and pattern of inheritance.
authors.affiliation: Department of Fetal Medicine, Maternal and Child Health Hospital of Sichuan Province, Chengdu, Sichuan 610045, China. qinshengfang@126.com.
authors.forename: Shengfang
authors.initials: S
authors.lastname: Qin
authors.forename: Xueyan
authors.initials: X
authors.lastname: Wang
authors.forename: Yunxing
authors.initials: Y
authors.lastname: Li
authors.forename: Ping
authors.initials: P
authors.lastname: Wei
authors.forename: Chun
authors.initials: C
authors.lastname: Chen
authors.forename: Lan
authors.initials: L
authors.lastname: Zeng
mesh_terms: D002899:Chromosomes, Human, Pair 9 / Q000235:genetics; D005260:Female; D006801:Humans; D007223:Infant; D059785:Karyotype; D008297:Male; D012303:Ring Chromosomes; D025064:Sex Chromosome Disorders / Q000235:genetics*