Identification of a case of maternal uniparental disomy of chromosome 10 associated with confined placental mosaicism

Abstract

We report a case of maternal uniparental disomy of chromosome 10 discovered after chorionic villus sampling (CVS). Direct preparations revealed mosaic trisomy 10, while cultured CVS cells, as well as amniotic fluid cells, showed only a normal 46,XY complement. DNA analysis using microsatellite markers showed both chromosomes 10 to have been inherited from the mother. The pregnancy was complicated by polyhydramnios. A phenotypically normal male infant of appropriate size was delivered by Caesarean section at 41 weeks' gestation. Since only the direct preparations showed trisomy 10, this case illustrates the importance of CVS direct preparations in the detection of pregnancies at risk of uniparental disomy (UPD). Although the increased frequency of confined placental mosaicism (CPM) diagnosed when direct preparations are performed has been viewed negatively, identification of both CPM and UPD may have biological and clinical significance for a pregnancy. Even though only a single case of maternal disomy 10 is reported here, the apparently normal phenotype provides evidence that there are no major imprinted loci on chromosome 10 that affect in utero growth and development. However, other potential effects such as mental retardation will require long-term follow-up of this as well as additional cases.

Systematic search for uniparental disomy in early fetal losses: The results and a review of the literature

“…In fact one case of upd(10)mat, previously reported from our laboratory, did not show trisomy 10 in cultured cells, only in the direct preparation. If the direct preparations had not been performed, this case would have been missed as CPM and as a possible UPD [Jones et al, 1995]. Direct preparations were not performed on any of the 18 spontaneous abortions presented here.…”

Fetal trisomy 10 mosaicism: ultrasound, cytogenetic and morphologic findings in early pregnancy

“…This finding might be attributed to the low number of trisomic cells in lymphocytes (2 out of 50 cells). In addition to the variable degree and distribution of trisomic cells within the fetus, uniparental disomy (UPD) of the other cells with the 'normal' karyotype might account for further phenotypic variation (Jones et al, 1995).…”

Trisomy 10 mosaicism and maternal uniparental disomy 10 in a liveborn infant with severe congenital malformations

“…Maternal uniparental disomy (10) (m(UPD)10) has been reported twice: uniparental heterodisomy by Jones et al [1995], and uniparental isodisomy by Schlegel et al [2002].…”