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Recognize the signs and symptoms of AADC deficiency

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

Hypotonia1

  • Most commonly reported symptom
Hyptonia reported in AADC deficiency patients
Hypotonia
n=74

Developmental delay1

  • In AADC deficiency, developmental delay may include impairments in head control, crawling, or standing, and speech delays2,3
Developmental delay reported in AADC deficiency patients
Developmental delay
n=49

Movement disorders

Oculogyric crisis1

  • Episodes of sustained upward or lateral deviation of the eyes, rhythmic orofacial movements, backward and lateral flexions of the neck, tongue protrusion, and jaw spasms4
  • Can last a few seconds or persist for several hours, and occur several times a day or week5
  • May not be present in all cases1
  • Often misdiagnosed as a seizure, epilepsy, cerebral palsy, or mitochondrial disease5,6
Oculogyric crisis
n=67

Caregivers and parents of children with AADC deficiency may have not heard of the term “oculogyric crisis” before. When describing these episodes, they may talk about observing their child suddenly4:

  • Rolling their eyes back
  • Hyperextending their head, neck, or back
  • Thrusting their tongue
  • Contracting muscles and/or twisting involuntarily

They may even describe the episodes as seizures since they may not be familiar with oculogyric crises.5,6

WATCH: Take a closer look at an oculogyric crisis episode

Other movement disorders and associated symptoms include1:

  • Dystonia (53%) n=41
  • Hypertonia (44%) n=35
  • Hypokinesia (32%) n=25

Autonomic symptoms include1:

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

“If all of these symptoms are observed, the diagnosis can be made. But, if you have no experience or knowledge about it, you may have difficulty making a diagnosis.”

Takanori Yamagata, MD
Department of Pediatrics, Jichi Medical University, Shimotsuke, Tochigi, Japan

Learn more about the symptoms that should prompt an investigation of AADC deficiency

Download the Symptom Guide
Learn about common misdiagnoses and the signs to differentiate

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 W-L, Chien Y-H, Lee N-C, 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. 4. Hwu W-L, 
Lee N-C, Chien Y-H, et al. AADC deficiency: occurring in humans, modeled in rodents. Adv Pharmacol. 2013;68:273-284. 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 W-T. Disorders of monoamine metabolism: inherited disorders frequently misdiagnosed as epilepsy. Epilepsy Seizure. 2010;3(1):147-153. doi: 10.3805/eands.3.147.