iNTD - International Working Group on Neurotransmitter Related DisordersPatient Registry

About iNTD

Major aims of the study:

  1. To describe the natural history and outcome of the six neurotransmitter disorders, five BH4 deficiencies and two cerebral folate deficiencies
    1. Long-term organ-specific complications
    2. Survival rate
    3. Genotype/phenotype correlation
    4. Differences in the disease course relating to the genetic background / ethnic origin/ gender effects
  2. To describe and evaluate the efficacy and safety of current treatment strategies
  3. To compare the diagnosis, treatment and management of affected individuals in different European countries.
  4. To identify the major impact of a rare inherited disease for patients and their families regarding the quality of life, school education, professional career and social life


Patients with any of the following diseases could be included:

  • Neurotransmitter disorders
    • Aromatic amino acid decarboxylase (AADC) deficiency
    • Tyrosine hydroxylase (TH) deficiency
    • Dopamine beta-hydroxylase (DH) deficiency
    • Monoamine oxidase A (MAOA) deficiency
    • Dopamine transporter (DAT) deficiency
    • Vesicular monoamine transporter 2 (VMAT) deficiency
  • BH4 Deficiencies
    • Autosomal recessive GTP cyclohydrolase deficiency
    • Autosomal dominant GTP cyclohydrolase deficiency (Segawa disease)
    • 6-Pyruvoyl-tetrahydropterin synthase (PTPS) deficiency
    • Dihydropteridine reductase (DHPR) deficiency
    • Sepiapterin reductase (SR) deficiency
  • Cerebral folate deficiencies
    • Folate receptor alpha (FOLR1) deficiency
    • Dihydrofolate reductase (DHFR) deficiency
  • Serine deficiency disorders
    • 3-phosphoglycerate dehydrogenase (3-PGDH) deficiency
    • 3-phosphoserine phosphatase (3-PSP) deficiency
    • Phosphoserine aminotransferase deficiency
  • Disorders of glycine metabolism
    • Glycine encephalopathy, also known as Non-ketotic hyperglycinaemia
  • GABA related disorders
    • GABA-transaminase-deficiency
    • Succinate-semialdehyde-dehydroxylase deficiency
  • Co-chaperon deficiencies
    • DNAJC12 deficiency
  • Patients with suspicious CSF results (suggesting neurotransmitter related disorder) without known diagnosis



  1. Baseline visit (B): once at the beginning
  2. Regular visits (R1, 2, 3): at least once yearly
  3. Fatal disease course visit (F): once in case of fatal disease course



  • Check inclusion/exclusion criteria
  • Written informed consent



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