Is Mosaic trisomy 9 inherited ?
Is mosaic trisomy 9  inherited? Mosaic trisomy 9 is usually not inherited. It often occurs sporadically as a random event during the formation of the reproductive cells (egg and sperm) or as the fertilized egg divides. In rare cases, mosaic trisomy 9 may be inherited from a parent with a chromosomal rearrangement called a "pericentric inversion." This occurs when a segment of chromosome 9 has broken off in two places, swiveled round 180 degrees and reinserted itself into the chromosome. In these cases, the parent has a "balanced" rearrangement, meaning the piece of chromosome is in a different order but no genetic material is gained or lost. Carriers of a balanced rearrangement typically to not have any symptoms or health problems. However, they may be at an increased risk of having children with an abnormal number or chromosomes.