title: Origin of 46,XY/46,XY,r(19) mosaicism.
abstract: We report on a case of 46,XY/46,XY,r(19) mosaicism. The patient shows minimal clinical abnormality and the terminal deletions prerequisite for the ring formation are not microscopically discernible. The origin of the mosaicism is discussed. Firstly, the mosaicism may represent chimerism with a prezygotic origin of the ring chromosome; secondly, the ring chromosome could have arisen postzygotically; and thirdly, the ring could have been of a prezygotic origin with the apparently normal cells actually containing reopened rings. The consequences of these hypothesis on genetic counselling are discussed.
authors.affiliation: Department of Pathology, Mercy Hospital and Medical Center, Chicago, IL.
authors.forename: J F
authors.initials: JF
authors.lastname: Yung
authors.forename: D B
authors.initials: DB
authors.lastname: Sobel
authors.forename: J J
authors.initials: JJ
authors.lastname: Hoo
mesh_terms: D002888:Chromosomes, Human, Pair 19; D006801:Humans; D007231:Infant, Newborn; D007621:Karyotyping; D008297:Male; D009030:Mosaicism / Q000235:genetics*