Phenylalanine hydroxylase deficiency is an inherited disorder caused by the build up of phenylalanine in the blood. Phenylalanine is a basic building block of proteins (an amino acid) that is present in food. Affected people carry genetic variants of the PAH gene, which gives instructions to make the phenylalanine hydrolase enzyme involved in the break down of phenylalanine. People with PAH variants produce an enzyme with reduced activity, leading to build up of phenylalanine and the characteristic symptoms of intellectual disability and other health problems. This condition is also known as phenylketonuria or PKU.
Take this test to find out whether you are a genetic carrier for PAH variants and are at risk of passing it to your children. This is intended to be a carrier screening test for couples who are considering to start a family.
Phenylalanine hydroxylase deficiency is caused by genetic variation in the PAH gene, which gives instructions to make the phenylalanine hydrolase enzyme involved in the break down of phenylalanine. People with PAH variants produce an enzyme with reduced activity, leading to build up of phenylalanine. Cells in the brain are most affected as it leads to the destruction of the fatty covering (myelin) of nerve cells. More than 900 variants are known each affecting enzyme activity to different degrees, accounting for the variable severity in symptoms.
Phenylalanine hydroxylase deficiency is inherited in an autosomal recessive pattern, which means two defective copies of the PAH gene must be inherited in order for symptoms to appear.
This test looks at twenty three genetic variants of the AH gene that occur those of Irish, Turkish, East Asian and European descent.
Understanding your carrier status for these variants will help you understand the risk of passing it to your children.
While it provides a risk analysis for these conditions, it may be necessary to use gene and genome sequencing tests, as additional genetic variants are linked to PKU.
Based on underlying genetic cause and disease severity phenylalanine hydroxylase deficiency can be distinguished into two types: classic PKU and variant PKU. Classic PKU is the most severe form and often present with the following symptoms
- Intellectual disability
- Behavioural problems
- Decreased hair and skin pigmentation
How It Works
Step 1: Sign up for a free Genebase account.
Step 2: Upload your DNA markers to Genebase.
Step 3: Login to your account to access your results when they are ready.