How id pku inherited?

Recessive gene trait. We each have pairs of any specific gene & these reside on the chromosome passed from the respective parent.When a defective gene comes from one parent, but not the other, the normal gene can keep up with the bodies needs. (no PKU) If both parents pass the bad gene, no work is done & PKU develops.If one defective gene produced the problem it would be called a "dominant" gene or inheritance.
PKU. Phenylketonuria (pku) is inherited, which means it is passed down through families. Both parents must pass on the defective gene in order for a baby to have the condition. This is called an autosomal recessive trait.
Recessive. This means that the abnormal gene has to come from both parents who each have a single gene that makes them a genetic "carrier". This is more likely to occur when the parents are related as e.G 1st cousins. Although legal it is a risky union. We all have a chance of being a carier like this for many diseases. The disease will only occur if spouse has the same gene.