Molecular studies of trisomy 18.
We have determined the parental origin of 50 cases of trisomy 18. In 48 cases the additional chromosome was maternal in origin, and in 2 cases it was paternal in origin. Seven cases, including both those with an additional paternal chromosome, appeared to be the result of postzygotic error. In contrast to the situation in nondisjunction involving chromosomes 21 and X, there was no evidence for nullochiasmate nondisjunction.
Wessex Regional Genetics Laboratory, Salisbury District Hospital, United Kingdom.
J M
JM
Fisher
J F
JF
Harvey
R H
RH
Lindenbaum
P A
PA
Boyd
P A
PA
Jacobs
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002887:Chromosomes, Human, Pair 18; D005220:Fathers; D005260:Female; D006801:Humans; D008297:Male; D008423:Maternal Age; D008875:Middle Aged; D009030:Mosaicism; D009630:Nondisjunction, Genetic; D010375:Pedigree; D011995:Recombination, Genetic; D014314:Trisomy