title: Prenatal diagnosis and genetic counseling in a fetus associated with risk of Angelman syndrome with a small supernumerary marker chromosome derived from chromosome 22.
abstract: BACKGROUND
  Angelman syndrome (AS) is a neurodevelopmental disorder. AS patients concomitant with sSMC are rather rare events. It will provide more useful and proper information for genetic counseling to identify the sSMC origin.
  
  
  METHODS
  A 27-year-old woman was referred for genetic counseling and prenatal diagnosis at 26 weeks of gestation due to her elder daughter, diagnosed as Angelman syndrome (AS) with an interstitial deletion in one of the chromosomes 15, carrying a small supernumerary marker chromosome (sSMC). The G-banding results of the woman and her current fetus both were 47,XX,+mar. In this paper, fluorescence in situ hybridization (FISH) results showed that there was no deletion of chromosome 15 in the woman and fetus. We demonstrated that the proband's sSMC was maternally inherited and was an inv dup(22)(q11.1) , and that the deletion in 15q11.2-q13.1 was de novo.
  
  
  CONCLUSIONS
  Taking into account above results and normal phenotypes of the proband's mother, in this case we suggest that the sSMC don't increase the recurrence risk of AS. After prenatal diagnosis, the woman chose to continue the pregnancy, and finally gave birth to a normal female infant.
authors.affiliation: Institute of Laboratory Medicine, Jinling Hospital, Nanjing University School of Medicine, 305 East Zhongshan Road, Nanjing, Jiangsu 210002 China.
authors.forename: Yu-An
authors.initials: YA
authors.lastname: Hu
authors.affiliation: Institute of Laboratory Medicine, Jinling Hospital, Nanjing University School of Medicine, 305 East Zhongshan Road, Nanjing, Jiangsu 210002 China.
authors.forename: Yingxia
authors.initials: Y
authors.lastname: Cui
authors.affiliation: Institute of Laboratory Medicine, Jinling Hospital, Nanjing University School of Medicine, 305 East Zhongshan Road, Nanjing, Jiangsu 210002 China.
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Fan
authors.affiliation: Institute of Laboratory Medicine, Jinling Hospital, Nanjing University School of Medicine, 305 East Zhongshan Road, Nanjing, Jiangsu 210002 China.
authors.forename: Qiuyue
authors.initials: Q
authors.lastname: Wu
authors.affiliation: Institute of Laboratory Medicine, Jinling Hospital, Nanjing University School of Medicine, 305 East Zhongshan Road, Nanjing, Jiangsu 210002 China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Li
authors.affiliation: Institute of Laboratory Medicine, Jinling Hospital, Nanjing University School of Medicine, 305 East Zhongshan Road, Nanjing, Jiangsu 210002 China.
authors.forename: Weiping
authors.initials: W
authors.lastname: Wang
keywords: Angelman syndrome; Genetic counseling; Prenatal diagnosis; Small supernumerary marker chromosomes (sSMC)