What are the symptoms of phenylketonuria?
Dec 26, 2024
Source: Cainiu Health
Dr. Zhou Xiaofeng
Introduction
In general, phenylketonuria (PKU) is an inherited metabolic disorder. Its main symptoms include growth and developmental delays, a distinctive body odor, skin pigmentation and eczema, intellectual disability, and neurological damage. If there is a family history of this condition, it is recommended to undergo genetic counseling and testing to understand the risk of carrying the disease-causing gene.
Generally, phenylketonuria (PKU) is an inherited metabolic disorder, with main symptoms including growth and developmental delays, a distinctive body odor, skin pigmentation and eczema, intellectual disability, and nervous system damage. A detailed analysis is as follows:
1. Growth and Developmental Delays
Due to impaired phenylalanine metabolism, the body may poorly utilize nutrients, thus affecting growth and development. This can manifest as slow height growth, insufficient weight gain, delayed primary tooth development, sparse dentition, and delayed skeletal development.
2. Distinctive Body Odor
Metabolites such as phenylpyruvic acid accumulate in the body and are excreted through sweat and urine, producing a distinct odor. The sweat, urine, and exhaled breath of patients may contain high levels of phenylpyruvic acid, potentially giving off a peculiar musty or mousy smell.
3. Skin Pigmentation and Eczema
Accumulation of phenylalanine in the body may lead to increased skin pigmentation, causing the skin to appear darker. Eczema might be related to inflammatory skin reactions caused by metabolic abnormalities, potentially resulting in eczema-like rashes or even dermatographism.
4. Intellectual Disability
When phenylalanine cannot be metabolized normally, brain development may be affected. Patients may experience delayed intellectual development, with IQ scores commonly below those of healthy peers.
5. Nervous System Damage
High concentrations of phenylalanine and its metabolites may exert toxic effects on the nervous system. Patients may experience recurrent seizures, which can progress to epilepsy in severe cases. They may also exhibit psychological and behavioral abnormalities such as restlessness, depression, hyperactivity, and social withdrawal, as well as symptoms like increased or decreased muscle tone.
If there is a family history of this condition, it is recommended to undergo genetic counseling and testing to understand the risk of carrying the disease-causing gene and to develop a reproductive plan under the guidance of a physician.
