Chromosome analysis of a chorionic villus sample during the early weeks of Meg’s pregnancy reveals mosaic trisomy of chromosome 15. Later, amniotic fluid is examined and the cells shed from the fetus into the fluid all are euploid.
a. What might have happened to give rise to this discrepancy? Give 2 different explanations.
b. Which of your explanations above seems more likely, and why?
c. Meg’s baby is born and diagnosed with Prader-Willis Syndrome. Is this possibly related to the prenatal tests above? If so, what phenomenon and which parent’s chromosome(s) caused the Prader-Willi Syndrome?