Trisomy 1 mosaicism only detected on a direct chromosome preparation in a neonate

Abstract
A patient is described with trisomy 1 mosaicism which was discovered on 24‐h culture of a neonatal blood sample, but was not detectable on subsequent 48‐ and 72‐h cultures. This result complements other recent reports and has important implications for the detection of mosaicism in neonates.