Origin and outcome of pregnancies affected by androgenetic/biparental chimerism.
BACKGROUND
Androgenetic diploid cells confined to the placenta have recently been reported in several cases of normally developed fetuses in association with placental mesenchymal dysplasia (PMD).


RESULTS
We investigated two singleton, mildly growth-restricted, female pregnancies ascertained on the basis of PMD. One case had liver hemangiomas and both infants had multiple skin hemangiomas. Post-natal development was normal. Molecular marker analysis confirmed the diagnosis of androgenetic and normal mixed cell populations in the placenta. Both cases derived from a single maternal genome (M1) and two distinct paternal genomes (P1 and P2). In one case, the androgenetic cell population contained both paternal genomes (P1P2), with one shared in common with the biparental (M1P1) population. In the second case, the androgenetic lineage showed complete homozygosity (P2P2) for a paternal genome not common to the biparental cell population.


CONCLUSIONS
These new PMD cases help to define the range of possible clinical presentations of androgenetic/biparental mosaicism or chimerism. Placentas with androgenetic/biparental chimeric cell populations may derive from a single tri-pronuclear (3PN) zygote in which one or more parental genomes are not equally apportioned to the daughter cells in the first cell division.
Robinson
Wendy P
WP
Department of Medical Genetics, University of British Columbia, British Columbia, Canada. wprobins@interchange.ubc.ca
Lauzon
Julie L
JL
Innes
A Micheil
AM
Lim
Ken
K
Arsovska
Snezana
S
McFadden
Deborah E
DE
D000483:Alleles; D000728:Androgens / Q000378:metabolism*; D019070:Cell Lineage; D046528:Chimerism; D005260:Female; D005317:Fetal Growth Retardation; D016678:Genome; D006801:Humans; D008297:Male; D009030:Mosaicism; D011247:Pregnancy; D011248:Pregnancy Complications; D011256:Pregnancy Outcome; D013997:Time Factors; D016216:Ultrasonography, Prenatal
D000728:Androgens