Q: What does inversion of the chromosome mean?
A: There are two different forms of inversion:
- Paracentric inversion is inversion of a segment of a chromosome restricted to one arm.
- Pericentric inversion is an inversion of a segment of a chromosome involving part of both arms and the centromere (the center).
An inversion often results in no loss of genetic material, the cells seldom harbor any biological abnormalities, and the person is phenotypically -- outwardly and for all intents and purposes -- normal. If one of the parents has the same inversion pattern and this parent is normal, then it can be assumed that the baby is normal, too. If neither of the parents has this finding, then the inversion is 'de novo' (new) and it's not known what the effect of the inversion will be on the baby.