New Data Shows Devastating Impact of AADC Deficiency on Caregivers

SOUTH PLAINFIELD, N.J. – PTC Therapeutics, Inc. (NASDAQ: PTCT) today announced data from the first study on the impact of caring for a child with the ultra-rare genetic disorder, aromatic L-Amino acid decarboxylase deficiency (AADC-d). Results show that caregivers spend almost every waking moment caring for a child with AADC-d, requiring most to leave their jobs or reduce their working hours.1 The data presented at the Virtual ISPOR North America 2021 Conference detail new insights into the extent of the burden of AADC-d and the great need and value of effective treatments.

“As with so many rare diseases, there is a tremendous impact endured by a family caring for a child with AADC deficiency,” said Kylie O’Keefe, Senior Vice President, Global Commercial and Corporate Strategy, PTC Therapeutics, Inc. “These insights demonstrate the high unmet need for therapies and the associated benefits a treatment could provide to caregivers and their families.”

AADC-d is a fatal, ultra-rare, genetic disorder that causes severe disability and suffering, and the need for 24-hour care [2-5]. The study found that primary caregivers spent on average 15 hours a day (mean of 105 hours per week) on practical and emotional care and carrying out administrative tasks like planning and attending appointments [1].

The study showed that 75% of caregivers left their jobs or greatly reduced their working hours, and 55% needed additional help (paid or unpaid) to supplement the care they were providing to their children [1]. Unpaid support usually came from a partner who provided, on average, 37 hours of help a week (8-93 hours per week) [1]. Families who required paid support received, on average, 27 additional hours of help (10-35 hours per week) from a registered nurse or training nursing assistant [1].

Data from a PTC health utility study was also presented orally. The study, which was based on an online survey of 1,000 respondents from the French general public, showed that the utility values increased as the health of a child with AADC deficiency improved [6]. These data highlight the value of treating AADC-d and the pain and distress of its symptoms [6]. This work builds on PTC’s previous AADC health utility data presented at ISPOR Europe 2020.

About aromatic L-amino acid decarboxylase (AADC) deficiency
AADC deficiency is a fatal, ultra-rare genetic disorder that causes severe disability and suffering from the first months of life, affecting every aspect of life – physical, mental, and behavioral. The suffering of children with AADC deficiency is exacerbated by episodes of distressing seizure-like oculogyric crises, which can happen daily and last for hours, causing the eyes to roll up in the head, frequent vomiting, behavioural problems, difficulty sleeping, and life-threatening complications such as respiratory infections and gastrointestinal problems.

There are no effective treatments for AADC deficiency, and the lives of affected children are highly medicalized, sometimes involving many different medications to help manage symptoms, ongoing physical, occupational and speech therapy, and interventions, including surgery, to manage potentially life-threatening complications (infections, severe feeding and breathing problems and scoliosis).

While several diagnostic tests for AADC deficiency are available, the condition remains largely undiagnosed or misdiagnosed for other conditions with similar symptoms, such as cerebral palsy and some forms of epilepsy.

About PTC Therapeutics, Inc.
PTC Therapeutics is a science-driven, global biopharmaceutical company focused on the discovery, development and commercialization of clinically differentiated medicines that provide benefits to patients with rare disorders. PTC’s mission is to provide access to best-in-class treatments for patients with an unmet medical need, using its ability to globally commercialize products as the foundation to drive investment in a robust and diversified pipeline of transformative medicines. The Company’s strategy is to leverage its strong scientific expertise and global commercial infrastructure to maximize value for its patients and other stakeholders. To learn more about PTC, please visit us at and follow it on Facebook, on Twitter at @PTCBio, and on LinkedIn.


[1] Buesch K, Williams K, et al. Caring for an Individual with Aromatic L-amino Acid Decarboxylase (AADC) Deficiency: Analysis of Reported Time for Practical and Emotional Care and Paid/Unpaid Help. Poster presented at Virtual ISPOR North America 2021 Conference.
[2] Wassenberg T, 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.
[3]  Hwu WL et al. Natural History of Aromatic L-Amino Acid Decarboxylase Deficiency in Taiwan. JIMD Rep. 2018; 40:1-6.
[4]  Himmelreich N, et al. Aromatic amino acid decarboxylase deficiency: Molecular and metabolic basis and therapeutic outlook. Mol Genet Metab. 2019;127(1):12-22.
[5] Chien YH, et al. 3-O-methyldopa levels in newborns: Result of newborn screening for aromatic l-amino-acid decarboxylase deficiency. Mol Genet Metab. August 2016;118(4):259-263.
[6] Smith AB, Hanbury A, et al. A Discrete Choice Experiment to Derive Health State Utilities for Aromatic L-amino Acid Decarboxylase (AADC) Deficiency in France. Poster presented at Virtual ISPOR North America 2021 Conference


Kylie O’Keefe
+1 (908) 300-0691
[email protected]

Jane Baj
+1 (908) 912-9167
[email protected]