Carriers of the faulty gene that causes TSD are healthy, and would
only know of their carrier status if they had been tested or have had
a child with TSD. Carriers have about half the normal level of HexA,
but this is sufficient for completely normal brain and nerve function.
TSD can be avoided if couples are aware of their carrier status prior
to pregnancy.
It is only when two carriers have a child that has inherited both faulty
genes that no HexA is produced and TSD occurs. If both parents carry the
faulty gene, each pregnancy has a 1 in 4 (25%) risk of producing a TSD
affected child. A couple with healthy children may still be carriers,
and therefore should be tested to ensure further children are not affected
by TSD.
What if my partner is not Ashkenazi Jewish
You and your partner should still consider being tested. The risk in
this situation of having a child with TSD is about 1:30 000.
