The information on this website is not intended for diagnosis or treatment. Please consult your physician for health concerns.

+90 850 321 50 00

Phenylketonuria (PKU)

An inherited amino-acid metabolic disorder controlled by dietary therapy.

Written by: Saygı Hospital Health Guide Editorial Board
Last updated:

This content has been compiled by the Saygı Hospital Health Guide Editorial Board and is periodically reviewed by a specialist physician.

References (5)

This content is for informational purposes only and does not constitute medical advice. You can book an appointment at our Çocuk Sağlığı ve Hastalıkları department. Book Appointment →

What is Phenylketonuria (PKU)?

Phenylketonuria (PKU) is an autosomal recessive inherited metabolic disorder in which deficiency of phenylalanine hydroxylase (PAH) prevents the conversion of phenylalanine to tyrosine, leading to toxic accumulation of phenylalanine in the blood and brain.

Untreated PKU results in severe intellectual disability, behavioural disorders, seizures and hypopigmentation (fair hair, light skin). When diagnosed by newborn metabolic screening and a lifelong phenylalanine-restricted diet is started, normal development can be achieved.

Maternal PKU is a condition in which high maternal phenylalanine levels cause microcephaly, congenital heart disease and intellectual disability in the fetus; metabolic control before pregnancy is essential in women with PKU.

Symptoms

Intellectual developmental delay in untreated PKU
Seizures and hyperactivity
Mousy urine odour (phenylacetic acid)
Hypopigmentation: fair hair, blue eyes, light skin
Eczema-like skin rash
No symptoms before screening (in early diagnosis)

Risk Factors

Autosomal recessive inheritance: both parents are carriers
Consanguineous marriage
Family history of PKU
More common in some ethnic groups (Irish, Turkish)
Not having undergone newborn screening
Maternal PKU (the fetus is at risk if dietary control is not maintained in pregnancy)

When to See a Doctor?

If you experience any of the following symptoms, seek medical attention promptly:

  • Refer immediately to a metabolic specialist if the screening test is abnormal
  • When mousy odour or developmental delay is noticed
  • For routine metabolic follow-up of a child with PKU
  • If a woman with PKU is pregnant or planning pregnancy

Treatment Methods

01
Phenylalanine-restricted diet: natural protein is restricted and a special formula is used
02
Target blood phenylalanine: <360 µmol/L (varies by age)
03
BH4 (sapropterin) therapy: increases phenylalanine tolerance in BH4-responsive PKU
04
Pegvaliase: enzyme substitution in adult PKU (injection)
05
Neurological and neuropsychological developmental follow-up
06
Multidisciplinary team of dietician, neurologist and metabolic specialist

Which Department to Visit?

You can visit our Çocuk Sağlığı ve Hastalıkları department for these complaints. Our specialist physicians will create the most suitable treatment plan for you.

Learn About Çocuk Sağlığı ve Hastalıkları Department

Let us help you

You can make an appointment with our specialists or contact us for your concerns.

Book AppointmentContact Us

Related Health Topics

Other articles from the same department you may want to explore.

Newborn Care

Çocuk Sağlığı ve Hastalıkları

The newborn period is a critical phase that requires attentive care of the umbilical stump, temperature regulation, feeding, monitoring of jaundice and screening tests.

Vaccination Schedule

Çocuk Sağlığı ve Hastalıkları

The Turkish Ministry of Health national vaccination schedule arranges the immunization program from birth to adulthood. Timely and complete vaccination is critical in protecting community immunity.

Jaundice in Infants

Çocuk Sağlığı ve Hastalıkları

Neonatal jaundice (jaundice in newborns) presents as yellowing of the skin and eyes. The vast majority of cases are physiological and are easily treated with phototherapy.

Diarrhoea in Infants

Çocuk Sağlığı ve Hastalıkları

Acute diarrhoea is defined as 3 or more loose stools per day. In infants it is most often caused by viral gastroenteritis (rotavirus, norovirus); dehydration may lead to serious complications.

Fever Management in Children

Çocuk Sağlığı ve Hastalıkları

Fever in children (38°C and above) is the body's defense mechanism against viral or bacterial infection. Most fevers resolve spontaneously in 3-5 days; however, some conditions require urgent medical evaluation.

Cough in Children

Çocuk Sağlığı ve Hastalıkları

Cough is the most common symptom in children and is mostly due to viral upper respiratory infections. Cough lasting more than 3 weeks or with characteristic sounds requires detailed evaluation.

Bronchiolitis

Çocuk Sağlığı ve Hastalıkları

Supportive care with hydration, nasal suctioning, and oxygen if hypoxic is the mainstay; routine bronchodilators, corticosteroids, and antibiotics are not recommended per AAP/NICE guidelines.

Croup (Laryngotracheobronchitis)

Çocuk Sağlığı ve Hastalıkları

Croup is a viral inflammation of the larynx and trachea presenting with a barking cough, hoarseness, and inspiratory stridor. It mostly affects children aged 6 months to 3 years.

Health Disclaimer: The information on this page is prepared for general informational purposes only. It does not replace medical diagnosis and treatment. Please consult your physician for your complaints. Saygı Hospital does not accept responsibility for actions taken based on the information on this page.