Quick Facts

Phenylketonuria is "the inherited inability to metabolize phenylalanine that causes brain and nerve damage if untreated." It is a very common disease in the United States and other heavily populated areas such as the United Kingdom. It was discovered in 1934 by a Norwegian scientists named Dr. Asbjorn. Also, it affects newborns but can easily made less severe by keeping a low Phenylalanine diet during pregnancy. (quoted information was taken from

Side Effects

Phenylketonuria has many side effects, though it does not shorten the life expectancy of anyone with this disease. Some are quite harmless while others can be life changing. For example, the mild effects of PKU are behavioral problems, a musty odor to the skin, light hair and skin, low birth weight, and an abnormally small head (this condition is known as microcephaly). Though, PKU can also cause poor mental health, seizures, delayed development, eczema, heart defects, and increased risk of miscarriage. If you or someone you know is experiencing more than one of these symptoms, they may want to consider consulting a doctor.

Diagnostic Tests

PKU can be quite common in highly populated and polluted areas. It occurs in 10,000-15,000 newborns every year. Doctors figure out if a child has this disease by doing diagnostic tests. For example, if a pregnant woman has a family history of PKU they will perform screening tests on the child while it is still in the womb. If they detect the disease, when the baby is born, they will take blood tests after 24 hours of its birth. If you do not have a family history of PKU, your child will still have screening tests done on them. In fact, America is working towards have these tests performed on every baby born in hospitals.


Phenylketonuria is a single gene mutation. Which means that it is the result of a single gene, in this case it is found on Chromosome 12, that has been mutated. Also, Phenylketonuria is a recessive trait which means that there is a lesser chance of an offspring inheriting PKU.

Below are a few links to visit if you need more information, would like to get help with a low Phenylalanine diet, or would like to see PKU related events.