Analysis of DNA polymorphisms suggests that most de novo dup(21q) chromosomes in patients with Down syndrome are isochromosomes and not translocations

S E Antonarakis; P A Adelsberger; M B Petersen; F Binkert; A A Schinzel

Analysis of DNA polymorphisms suggests that most de novo dup(21q) chromosomes in patients with Down syndrome are isochromosomes and not translocations

Am J Hum Genet. 1990 Dec;47(6):968-72.

Authors

S E Antonarakis¹, P A Adelsberger, M B Petersen, F Binkert, A A Schinzel

Affiliation

¹ Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD.

PMID: 1978562
PMCID: PMC1683910

Abstract

Down syndrome is rarely due to a de novo duplication of chromosome 21 [dup(21q)]. To investigate the origin of the dup(21q) and the nature of this chromosome, we used DNA polymorphisms in 10 families with Down syndrome due to de novo dup(21q). The origin of the extra chromosome 21q was maternal in six cases and paternal in four cases. Furthermore, the majority (eight of 10) of dup(21q) chromosomes were isochromosomes i(21q) (four were paternal in origin, and four were maternal in origin); however, in two of 10 families the dup(21q) chromosome appeared to be the result of a Robertsonian translocation t(21q;21q) (maternal in origin in both cases).

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S.

MeSH terms

Chromosome Aberrations*
Chromosomes, Human, Pair 21*
Down Syndrome / genetics*
Fathers
Female
Humans
Male
Polymorphism, Restriction Fragment Length*
Translocation, Genetic*