Management Guidelines
Evaluations Following Initial Diagnosis
To establish the extent of disease and needs in an individual diagnosed with GTP cyclohydrolase 1-deficient dopa-responsive dystonia (GTPCH1-deficient DRD), the evaluations summarized (if not performed as part of the evaluation that led to the diagnosis) are recommended.
Table 3.
Recommended Evaluations Following Initial Diagnosis in Individuals with GTPCH1-Deficient DRD
Organ System | Evaluation | Comment
Neurologic
| Baseline neurologic exam | Important to assess severity of symptoms prior to starting levodopa administration
Other
| Consultation w/clinical geneticist /or genetic counselor |
Treatment of Manifestations
Table 4.
Treatment of Manifestations in Individuals with GTPCH1-Deficient DRD
Manifestation | Treatment | Considerations/Other
Dystonia/
Parkinsonism
| Levodopa/DCI | • Initial suggested dose1,2,3 (a levodopa trial):• Children 6 yrs: 1-10 mg/kg levodopa/DCI daily, administered in multiple doses3
Children ≥6 years: 25-50 mg levodopa/DCI 1-3x/day
Adults: 50 mg levodopa/DCI 1-3x/day
Changing the dose slowly by small increments is recommended.
Motor benefit can be recognized immediately or w/in a few days of starting levodopa therapy; full benefit occurs w/in several days to a few months.
Maximum benefit (complete or near-complete responsiveness of symptoms) is generally achieved by 300-400 mg/day of levodopa/DCI.
Transient dyskinesias
assoc w/initiation
of treatment
Source: GeneReviews — "GTP Cyclohydrolase 1-Deficient Dopa-Responsive Dystonia"
