Mosaic vs. nonmosaic trisomy 9: Report of a liveborn infant evaluated by fluorescence in situ hybridization and review of the literature

• Published in: American journal of medical genetics Vol. 62; no. 4; pp. 330 - 335
• Main Authors: Cantú, Eduardo S., Eicher, Dorothea Jenkins, Shashidhar Pai, G., Donahue, Christopher J., Harley, Russell A.
• Format: Journal Article
• Language: English
• Published: New York Wiley Subscription Services, Inc., A Wiley Company 24-04-1996; Wiley-Liss
• Subjects: Abnormalities, Multiple - genetics; Adult; Autopsy; Biological and medical sciences; Chromosome aberrations; Chromosomes, Human, Pair 9; congenital defects; Fatal Outcome; Female; FISH; Humans; In Situ Hybridization; Infant, Newborn; Male; Medical genetics; Medical sciences; Mosaicism; Trisomy; trisomy 9; Chromosomal aberration; Human; Molecular hybridization; Trisomy; In situ; Bibliographic survey; Fluorescence; Aneuploidy; Chromosome C9; Case study; Phenotype; Newborn; Cytogenetics; Mosaicism
• ISSN: 0148-7299; 1096-8628
• DOI: 10.1002/(SICI)1096-8628(19960424)62:4<330::AID-AJMG1>3.0.CO;2-V

We report on a newborn infant with multiple congenital anomalies and apparent nonmosaic trisomy 9 in the blood (by conventional cytogenetic studies) who died shortly after birth. Clinical observations at birth and autopsy are compared with phenotypes of mosaic and nonmosaic trisomy 9 cases reported previously. Unlike the initial cytogenetic analysis, fluorescence in situ hybridization (FISH) studies of metaphase and interphase blood cells and skin fibroblasts detected the presence of euploid and trisomy 9 cells. These results suggest that earlier reports of trisomy 9, which relied on conventional chromosome analysis of a few metaphase cells and/or only one tissue type, may not have excluded mosaicism, and that trisomy 9 may be viable only in the mosaic state. © 1996 Wiley‐Liss, Inc.