Phenylketonuria is best described as what type of disorder?

Phenylketonuria (PKU) is classified as a genetic disorder because it results from a deficiency in an enzyme (phenylalanine hydroxylase) that is necessary for the metabolism of the amino acid phenylalanine. This enzyme deficiency is caused by mutations in the PAH gene, which is inherited in an autosomal recessive manner. As a result, individuals with PKU cannot effectively convert phenylalanine into tyrosine, leading to toxic levels of phenylalanine that can cause serious neurological damage if not managed through dietary restrictions. The genetic basis of PKU is key to understanding how it presents and is treated, highlighting its classification as a disorder resulting specifically from inherited genetic mutations.