phenylketonuria
Meaning of phenylketonuria: Phenylketonuria is an inherited disorder that impairs breakdown of the amino acid phenylalanine, which then accumulates and can impair development if untreated.
Definition of phenylketonuria
Phenylketonuria is an inherited metabolic disorder caused by a deficiency of the enzyme responsible for breaking down phenylalanine, an amino acid obtained from dietary protein. Without this enzyme working properly, phenylalanine builds up in the blood and body tissues to levels well beyond what the body normally tolerates.
Untreated, elevated phenylalanine can damage the developing brain and nervous system, leading to intellectual disability, behavioral and movement problems, seizures, and delayed development. Because these effects can be prevented, phenylketonuria is included in routine newborn screening in many places, allowing the condition to be identified through a blood test soon after birth, before symptoms appear.
Management centers on a diet that limits phenylalanine intake, allowing the body to avoid the levels of buildup that would otherwise cause harm. The condition is commonly abbreviated PKU and is inherited in a pattern requiring an altered gene from each parent.
Also known as
Used in a sentence
Newborn screening results prompted further testing to confirm or rule out phenylketonuria.
Good to know
Phenylketonuria is identified through routine newborn screening rather than through symptoms, since the condition typically causes no noticeable signs in the earliest period of life, before dietary management begins.
Word origin
Where “phenylketonuria” comes from
Formed from phenylketone, a chemical byproduct produced when phenylalanine cannot be broken down normally, and -uria, from Greek ouron, meaning urine, referring to the presence of these compounds in the urine.