MING CHEN2018-09-102018-09-102004http://www.scopus.com/inward/record.url?eid=2-s2.0-3042541737&partnerID=MN8TOARShttp://scholars.lib.ntu.edu.tw/handle/123456789/311959Objective: A fetus having partial trisomy of the distal part of chromosome 21q due to a de novo translocation is reported here. Method: A 29-year-old woman received amniocentesis at 18 weeks of gestation because of abnormal ultrasound findings including bilateral choroid plexus cysts, atrioventricular septal defects, rocker-bottom feet, and possible hydrocephalus. Results: Cytogenetic analysis revealed 46,XY, add(1)(p36.3), in which an additional material of unknown origin was attached to one of the terminal short arms of chromosome 1. Parental blood studies showed normal karyotypes in both parents. Spectral karyotyping was then performed and the origin of the additional material locating at chromosome 1p was found to be from chromosome 21. Conventional fluorescence in situ hybridization analysis was also used and confirmed the spectral karyotyping findings by use of a chromosome 21 specific painting probe, a locus specific probe localized within bands 21q22.13-q22.2 and a 21q subtelomeric probe. A hidden Down syndrome caused by a de novo translocation in this fetus was therefore diagnosed and the karyotype was designated as 46,XY, der(1)t(1;21)(p36.3;q22.1).ish der(1)(WCP21+, LSI 21+, 1pTEL-, 21q TEL+) de novo. Clinical features of the 1p36 deletion syndrome are also reviewed and may contribute to some features of this fetus. Termination of pregnancy was performed at 20 weeks of gestation. Conclusion: To our knowledge, our case appears to be the first to have partial monosomy 1p and partial trisomy 21q caused by de novo translocation being diagnosed prenatally. Copyright ? 2004 S. Karger AG, Basel.Choroid plexus cyst; Derivative chromosome; Down syndrome; Fluorescence in situ hybridization; Spectral karyotyping; Trisomy 21[SDGs]SDG3amniocentesis; case report; choroid plexus tumor; chromosome 1; chromosome 1p; chromosome 21; chromosome deletion; cytogenetics; Down syndrome; fetus; fetus outcome; fluorescence in situ hybridization; gene location; gene translocation; human; hydrocephalus; molecular probe; priority journal; review; spectral karyotyping; Adult; Chromosome Deletion; Chromosomes, Human, Pair 21; Down Syndrome; Female; Fetal Diseases; Humans; In Situ Hybridization, Fluorescence; Pregnancy; Prenatal Diagnosis; Spectral KaryotypingPrenatal diagnosis of a fetus affected with down syndrome and deletion 1p36 syndrome by fluorescence in situ hybridization and spectral karyotypingjournal article10.1159/000077965