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Recognize the signs and symptoms associated with AADC Deficiency

Symptom presentation in patients with Aromatic L-amino Acid Decarboxylase (AADC) Deficiency (%)1

In a clinical study of 78 patients who were diagnosed with AADC Deficiency, the following symptoms were documented1:


  • Most commonly reported symptom
Hyptonia reported in AADC Deficiency patients

Developmental delay1,2,4

  • Impairments in head control, sitting, crawling, or standing
  • Speech delays
Developmental delay reported in AADC Deficiency patients
Developmental delay

Movement disorders

Oculogyric crisis1-3,5,6

  • Episodes of sustained upward or lateral deviation of the eyes, rhythmic orofacial movements, backward and lateral flexions of the neck, tongue protrusion, and jaw spasms
  • Can last a few seconds or persist for several hours, and occur several times a day or week
  • May not be present in all cases
  • Often misdiagnosed as a seizure, epilepsy, cerebral palsy, or mitochondrial disease


  • Dystonia (53%) n=41
  • Hypokinesia (32%) n=25
Oculogyric crisis reported in AADC Deficiency patients
Oculogyric crisis

View this video of an oculogyric crisis.

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Video is used with permission: Suthar R, Sankhyan N, Singhi P. Teaching video neuroimages: Oculogyric crises in a 10-year-old girl. Neurology. 2019;92(1):e82. doi: 10.1212/WNL.0000000000006698.
Neurology is published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.

Autonomic symptoms1-3,5

  • Hyperhidrosis (65%) n=51
  • Hypersalivation (41%) n=32
  • Ptosis (39%) n=30
  • Nasal congestion (31%) n=24

Secondary symptoms may also be present2

  • Epileptic seizures
  • Sleep disturbances
  • Behavioral problems such as irritability or excessive crying
  • Autistic features
  • Gastrointestinal problems
    • Diarrhea
    • Constipation
    • Gastroesophageal reflux
  • Feeding difficulties 

References: 1. Brun L, Ngu LH, Keng WT, et al. Clinical and biochemical features of aromatic L-amino acid decarboxylase deficiency. Neurology. 2010;75(1):64-71. 2. Wassenberg T, Molero-Luis M, Jeltsch K, et al. Consensus guideline for the diagnosis and treatment of aromatic l-amino acid decarboxylase (AADC) deficiency. Orphanet J Rare Dis. 2017;12(1):12. doi: 10.1186/s13023-016-0522-z. 3. Hwu WL, Lee NC, Chien YH, et al. AADC deficiency: occurring in humans, modeled in rodents. Adv Pharmacol. 2013;68:273-284. 4. Hwu WL, Chien YH, Lee NC, et al. Natural history of aromatic L-amino acid decarboxylase deficiency in Taiwan. JIMD Rep. 2018;40:1-6. doi: 10.1007/8904_2017_54. 5. Pons R, Ford B, Chiriboga CA, et al. Aromatic L-amino acid decarboxylase deficiency: clinical features, treatment, and prognosis. Neurology. 2004;62(7):1058-1065. 6. Lee WT. Disorders of monoamine metabolism: inherited disorders frequently misdiagnosed as epilepsy. Epilepsy & Seizure. 2010;3(1):147-153. Accessed January 17, 2019.