mosaicism

noun

Etymology: Etymology tree Ancient Greek Μοῦσᾰ (Moûsă) Proto-Indo-European *-yósder. Ancient Greek -ῐος (-ĭos)? Ancient Greek -ῐον (-ĭon) Ancient Greek -εῖον (-eîon) Ancient Greek Μουσεῖον (Mouseîon) Ancient Greek μουσεῖον (mouseîon)der. Late Latin mūsīvum Medieval Latin musaicumbor. Italian mosaicoder. Middle French mosaïqueder. English mosaic Proto-Indo-European *-id- Proto-Indo-European *-yéti Proto-Indo-European *-idyéti Proto-Hellenic *-íďďō Ancient Greek -ῐ́ζω (-ĭ́zō) Proto-Indo-European *-mos Proto-Indo-European *-mós Ancient Greek -μός (-mós) Ancient Greek -ισμός (-ismós)der. English -ism English mosaicism From mosaic + -ism.

1. The condition in which more than one genetically distinct population of cells coexist within one individual.

   “Some but not all of the cells that made up the fetus […] had an extra chromosome on the twentieth pair. A mosaicism, it was called.”