OBJECTIVES

AADC-d is an extremely rare autosomal recessive neuro-metabolic disease characterized by a complex syndrome of motor, behavioral, and autonomic symptoms. The aim of this study, part of a global study assessing the burden of AADC-d, was to describe symptoms and developmental motor milestones in French patients.

METHODS

A case study questionnaire based on literature data and clinician input was developed. The dimensions covered by this questionnaire were the following: patient characteristics, disease course, healthcare resources required for follow-up and treatment of patients by degree of severity. French physicians experienced in the management of AADC-d patients and practicing in 12 expert centers were invited to participate in the study. Each physician was asked to complete a questionnaire for each AADC-d patient he/she was treating or had treated based on the information available in medical records and his/her knowledge of his/her patient(s).

RESULTS

Six physicians were interviewed. Seven patient cases were reported: 5 severe (no motor function) and 2 with “milder” symptoms (able to walk without assistance). Five patients were still alive (average age of 10-years) and 2 patients had died (mean death age of 7-years). Symptoms appeared in the first months of life for all patients. Patients were diagnosed as early as 4 months of age, and 75% were diagnosed before 1 year old. All patients have developed typical symptoms of AADC-d: oculogyric crisis, delayed motor and speech development and insomnia. Over 75% of patients had developed dyskinesia, delayed cognitive development, excessive drooling or feeding problems. Severe patients had a higher number of symptoms, some of them being specific (e.g. hypotonia, hypertonia, hypokinesia/bradykinesia, excessive crying, excessive sweating, diarrhea).

CONCLUSIONS

This study shows the burden of AADC-d through the wide variety of symptoms in both mild and severe patients. These data will be used to support an HTA submission in France.