IVF (In Vitro Fertilization) and CdLS

We have twins, which were conceived via the IVF process. Only one twin is affected with CdLS. As part of the IVF process my wife produced numerous eggs, which were processed and made embryos. Two were placed into her (hence the twin boys), while we froze approximately 5-7 embryos for future use. Is there any research or history that shows any correlation with IVF and CdLS? We are trying to determine, whether or not we should keep the frozen embryos, in the instance that the medication or hormones during the IVF process may have contributed, or if the issue with CdLS is genetic and would be in the chromosome and would most likely still apply even if we went through a fresh cycle of IVF.

We haven’t seen an increase in CdLS in assisted reproductive procedures although numbers are small at this time. Our belief is that the changes (mutations) in the CdLS gene generally occur in a single egg or sperm or very soon after they come together in over 99% of families, provided neither parent has any features of CdLS themselves. In a very small percent of families that mutation may have happened in a precursor cell that went in to form a group of eggs or sperm. This is called germ line mosaicism, and that is the cause in families where neither parent is affected, and testing in their blood for the gene change seen in their children is normal, but go on to have other children with CdLS. The risk of recurrence for this rare subset of families can be as high as 50%. Your frozen embryos are most likely unaffected but can be tested for either by preimplantation genetic diagnosis or by an early CVS or amniocentesis after successful implantation provided a known mutation was identified in your child. Prenatal diagnosis can only be done in CdLS if a detectable mutation has been found in the affected child.

IK – TK 3/25/11