PKU is a recessive genetic condition requiring two copies of the gene, with a spectrum of severity including hyperphenylalaninemia.

“so it's a recessive condition meaning it takes two to tango both your parents are care for that condition um within this there is a spectrum um so we have individuals that are what we call hyper fenal Alan anemic so they don't technically have PKU they're not symptomatic they wouldn't have problems with intellectual disabilities but it's a spectrum of severity”