PKU and Genetics

Since I have PKU will my child also have it?

Most Likely Outcome: Although you have PKU, in most cases (49 times out of 50), your partner will not have PKU and will not be a carrier, so your baby will not inherit the disorder, as shown in this figure.

Your child will most likely not have PKU, but will be a carrier. A person who is a carrier of PKU does not have the disorder or show any symptoms of it, but carries a gene for the disorder. About 1 in 50 people is a carrier of the PKU gene.

Rare Outcome: If you have PKU, and your partner is a carrier of PKU (rare possibility — 1 chance out of 50), your child will then have a 50% chance of having PKU, as shown in the figure below.

In the very rare case where both you and your partner have PKU, all of your children will have PKU, as shown below.

You and your partner can get genetic counseling to find out the risk of passing PKU on to your children.  Contact your metabolic clinicians or get a referral to a genetic counselor.