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Interdisciplinary CompetenceMolecular Diagnostics
Know how in the analysis of genetic material.
For the benefit of patients.

IllnessPhenylketonuria, differential diagnosis


Short information

Comprehensive differential diagnostic panel for Phenylketonuria containing 1 core gene and altogether 6 guideline-curated genes according to the clinical signs

Number of genes
6 Accredited laboratory test
Examined sequence length
1,4 kb (Core-/Core-canditate-Genes)
8,1 kb (Extended panel: incl. additional genes)
Analysis Duration
on request
  • EDTA-anticoagulated blood (3-5 ml)
Diagnostic indications



Gene panel

Selected genes

NameExon Length (bp)OMIM-GReferenz-Seq.Heredity
GCH1753NM_000161.3AD, AR

Informations about the disease

Clinical Comment

In phenylketonuria (PKU), the concentration of phenylalanine in the blood is greatly increased. Absorbed through food, high phenylalanine concentrations lead to intellectual deficits and other health problems, with symptoms varying from mild to severe (classic PKU). In classic PKU, newborn develop normally for the first few months. If left untreated, permanent intellectual disability develops, often with seizures, developmental delays, behavioral problems and psychiatric problems. PKU children tend to have lighter skin and hair than unaffected family members and are prone to eczema. Less severe forms have a lower risk of brain damage. Babies born to mothers with PKU/uncontrolled phenylalanine levels have significant risks for intellectual disability along with low birth weight and growth retardation; heart defects, microcephaly and behavioral abnormalities occur as well. PKU and hyperphenylalaninemia are inherited in autosomal recessive manner. With typical laboratory-chemical findings, definite molecular genetic diagnoses are achieved in all patients, provided that targeted deletion/duplication analysis is also applied to show 1-3% of mutations as indels. Clinical diagnosis can be virtually ruled out by a negative molecular genetic result.

Reference: https://www.ncbi.nlm.nih.gov/books/NBK1504/


  • Alias: Folling disease (PAH)
  • Alias: Folling's disease (PAH)
  • Alias: PAH deficiency (PAH)
  • Alias: PKU
  • Alias: Phenylalanine hydroxylase deficiency (PAH)
  • Alias: Phenylalanine hydroxylase deficiency disease (PAH)
  • Allelic: Bronchiectasis with or without elevated sweat chloride 1, modifier of (CFTR)
  • Allelic: Congenital bilateral absence of vas deferens (CFTR)
  • Allelic: Dystonia, DOPA-responsive, with/-out hyperphenylalaninemia (GCH1)
  • Allelic: Hyperphenylalaninemia, non-PKU mild (PAH)
  • Allelic: Hypertrypsinemia, neonatal (CFTR)
  • Allelic: Pancreatitis, hereditary (CFTR)
  • Allelic: Sweat chloride elevation without CF (CFTR)
  • Cystic fibrosis (CFTR)
  • Hyperphenylalaninemia, BH4-deficient, A (PTS)
  • Hyperphenylalaninemia, BH4-deficient, B (GCH1)
  • Hyperphenylalaninemia, BH4-deficient, C (QDPR)
  • Hyperphenylalaninemia, BH4-deficient, D (PCBD1)
  • Phenylketonuria (PAH)
Heredity, heredity patterns etc.
  • AD
  • AR
  • Multiple OMIM-Ps
ICD10 Code

Bioinformatics and clinical interpretation

No text defined