© 1994 Oxford University Press
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Early embryonic failure associated with uniparental disomy for human chromosome 21
The Action Research Laboratory for the Molecular Biology of Fetal Development, Royal Postgraduate Medical School, Institute of Obstetrics and Gynaecology, Queen Charlotte's and Chelsea Hospital Goldhawk Road, London W6 OXG, UK
*To whom correspondence should be addressed
Received April 19, 1994; Accepted May 19, 1994
As many as 16% of all recognized pregnancies may be anembryonlc, with failure of the embryo at a very early stage of development leaving only the extraembryonic components of the conceptus to proliferate. Studies In the mouse have shown that the maternal and paternal contributions to the genome of the zygote are not functionally equivalent, due to parental genomlc imprinting. Unlparental disomy can reveal Imprinting effects, as In this phenomenon both members of a chromosome pair are inherited from the same parent. We have carried out a systematic search for uniparental disomy In tissues from 23 cases of early embryonic failure, using variable number tandem repeat (VNTR) analysis and PCR amplification of polymorphic short sequence repeats. Two cases of maternal unlparental heterodisomy for chromosome 21 were identified. One case occurred in conjunction with trlsomy for chromosomes 7 and 9, but In the other case maternal uniparental heterodisomy for chromosome 21 was the only chromosomal abnormality found. We therefore postulate that there may be developmentally important genes on human chromosome 21 which are Imprinted such that both parental copies are essential for normal embryogenesls.
+These authors made an equal contribution to this work and are listed alphabetically.