MedicineNet.com
About Us | Privacy Policy | Site Map
February 9, 2010
MedicineNet home Picture Slideshows Diseases and conditions Symptoms and signs Procedures and tests Medications Picture Image Collection MedTerms medical dictionary Pet Health
Font Size
A
A
A


Phenylketonuria (PKU)

What is phenylketonuria?

Phenylketonuria (commonly known as PKU) is an inherited disorder that increases the levels of a substance called phenylalanine in the blood. Phenylalanine is a building block of proteins (an amino acid) that is obtained through the diet. It is found in all proteins and in some artificial sweeteners. If PKU is not treated, phenylalanine can build up to harmful levels in the body, causing intellectual disability and other serious health problems.

What are the symptoms of PKU?

The signs and symptoms of PKU vary from mild to severe.

The most severe form of this disorder is known as classic PKU.

  • Infants with classic PKU appear normal until they are a few months old.

  • Without treatment with a special low-phenylalanine diet, these children develop permanent intellectual disability.

  • Seizures, delayed development, behavioral problems, and psychiatric disorders are also common.

  • Untreated individuals may have a musty or mouse-like odor as a side effect of excess phenylalanine in the body.

  • Children with classic PKU tend to have lighter skin and hair than unaffected family members and are also likely to have skin disorders such as eczema.

Less severe forms of this condition, sometimes called variant PKU and non-PKU hyperphenylalaninemia, have a smaller risk of brain damage. People with very mild cases may not require treatment with a low-phenylalanine diet.

Babies born to mothers with PKU and uncontrolled phenylalanine levels (women who no longer follow a low-phenylalanine diet) have a significant risk of intellectual disability because they are exposed to very high levels of phenylalanine before birth.

  • These infants may also have a low birth weight and grow more slowly than other children.

  • Other characteristic medical problems include heart defects or other heart problems, an abnormally small head size (microcephaly), and behavioral problems.

  • Women with PKU and uncontrolled phenylalanine levels also have an increased risk of pregnancy loss.


Next: How common is phenylketonuria? »

Printer-Friendly Format  |  Email to a Friend


Suggested Reading by Our Doctors
MedicineNet Doctors
  • Eczema - Get information about eczema causes, skin symptoms, diagnosis and treatment. Types include dyshidrotic, atopic dermatitis, nummular, varicose and seborrheic eczema.
  • Miscarriage - Read about the possible causes for a miscarriage such as chromosomal abnormalities, diseases such as lupus, diabetes, thyroid disorders, and others.
  • Seizure (Epilepsy) - Learn about epilepsy, or seizure disorder. Causes include head injury, trauma, prenatal injury, poisoning, medications, stroke, heart attacks, alcoholism, infection, and more. Symptoms, diagnosis, and treatment information is included in the information.

Latest Medical News


Women's Health

Find out what women really need.


Are you Depressed? Take the Quiz

Your Guide to Symptoms & Signs: Pinpoint Your Pain



Phenylketonuria

What are genetic professionals and what do they do?

Genetics professionals are health care professionals with specialized degrees and experience in medical genetics and counseling. Genetics professionals include geneticists, genetic counselors and genetics nurses.

What is genetic counseling and evaluation?

Genetic professionals work as members of health care teams providing information and support to individuals or families who have genetic disorders or may be at risk for inherited conditions. Genetic professionals:

  • Assess the risk of a genetic disorder by researching a family's history and evaluating medical records.
  • Weigh the medical, social and ethical decisions surrounding genetic testing.
  • Provide support and information to help a person make a decision about testing.
  • Interpret the results of genetic tests and medical data.
  • Provide counseling or refer individual...

Read the Genetic Counseling article »










Health categories:

Slideshows | Diseases & Conditions | Symptoms & Signs | Procedures & Tests | Medications | Image Collection | Medical Dictionary | Pet Health

Popular health centers:

Allergies | Arthritis | Blood Pressure | Cancer | Chronic Pain | Cold & Flu | Diabetes | Digestion | Eyesight | Health & Living | Healthy Kids

Hearing & Ear | Heart | Infectious Disease | Men's Health | Mental Health | News & Views | Pregnancy | Sexual Health | Skin | Women's Health | More...

MedicineNet.com:

About Us | Newsletters | RSS Feeds | Privacy Policy | Site Map | WebMD® | Medscape® | eMedicine® | eMedicineHealth® | RxList®

This website is certified by Health On the Net Foundation. Click to verify. This site complies to the HONcode standard for trustworthy health information:
verify here.

©1996-2010 MedicineNet, Inc. All rights reserved. Notices and Legal Disclaimer.
MedicineNet does not provide medical advice, diagnosis or treatment. See additional information.