Carrier screening uses DNA analysis (or enzyme analysis in the case of Tay Sachs) to look for mutations on the DNA chain, especially those which are associated with Canavan disease in the Ashkenazi population.
Carrier screening can be done through a doctor’s office or a hospital-based medical genetics program. The results generally take about 2 weeks.
Screening is most useful when done before starting a family. A carrier couple has a number of options for building a healthy family, which can be explained by a genetic counselor. They include pregnancy with prenatal screening, in-vitro fertilization, use of donor egg or sperm, and adoption. You may wish to view our video A Genetic Counselor on Options
In the case of a couple where one member has Jewish ancestry and the other does not, and the Jewish member is found to be a carrier, full gene sequencing of the relevant gene in the non-Jewish member should be considered.
A pregnant couple can also be screened for Canavan disease, with the fetus tested after the parents’ status is determined. The only options for a couple who are already pregnant with a child affected by Canavan disease are to terminate the pregnancy or give birth to the affected child.
Couples who have already given birth to a child affected by Canavan disease have the same options as any other carrier couple for continuing to build a family. It is vital that a family with a Canavan child work with a genetic counselor if they want to have more children.
Anyone who finds out they are a carrier of Canavan disease, whether by a screening test or by having an affected child, should inform any blood relatives of childbearing age, who should themselves consider screening.