What is the chance of having another child with mosaic down syndrome?
Is testing available? After having a child with any genetic condition or health problem, some families are interested in exploring the chance of having another child with the same condition. The chance typically given for having another child with DS is about I%, or a I in 100 chance. In families in whom a child with DS (without Mosaicism) was born, it is expected that almost all of the cases were due to an extra chromosome 21 in the sperm or egg. This suggests that for the portion of cases of Mosaic DS where the first change occurred in the sperm or egg, the recurrence estimate of about 1% should also apply. It is not clear if this is the best estimate for families in whom Mosaic DS occurred after conception. Although about 1% is currently the best estimate, their chance may be lower than this. During future pregnancies, some families may wish to learn in advance if the developing baby will have a type of DS. There are several testing options for families in this situation. Some of th
