Medknow Publications on behalf of Indian Society of Human Genetics
Abstract
Background: Human chimerism is rare and usually uncovered through
investigations of ambiguous genitalia or blood grouping or prenatal
diagnosis. Most of the publications on placental chimerism are mainly
case reports. There is no systematic search with sensitive techniques
for placental chimerism in human. Aim: This study was aimed to asses
placental chimerism through two sensitive molecular techniques i.e.,
interphase fluorescent in situ hybridization and quantitative
fluorescent PCR. Material and methods: Placental chimerism was
analyzed using X & Y dual color fluorescent in-situ hybridization
onto 154 placentae from natural conceptions, obtained at termination of
pregnancy between 7 to 16 weeks of gestation. Results: Three cases of
placental sex chromosome chimerism were observed (1.95%). Exclusion of
maternal contamination and diagnosis was confirmed later by
quantitative fluorescent PCR. Conclusion: This finding indicates that
placental chimerism in early human pregnancy is not rare