Figure 1
Brain window of low-dose head CT showing bilateral calcification in CN (white arrows). Figure adapted from a previous article [6].
Video 1
Illustration of parkinsonian syndrome, response to levodopa and early motor complications in a patient with RAB39B X-linked Parkinson Disease.
Part 1: Parkinsonian syndrome before treatment.
This video highlights features of the parkinsonian syndrome, before starting treatment with levodopa. (A) Hypokinetic decrement occurs when the patient performs the finger-to-nose test. (B) The patient’s gait is characterized by rigidity, slowing of gait, reduced arm swing and shorter step length.
Part 2: Response to treatment.
This video illustrates the clinical improvement following treatment with levodopa. (A) Steps lengths and walking speed are increased. (B) Bradykinesia and hypokinetic decrement are less pronounced when compared to video 1.
Part 3: Early-motor complications.
This video demonstrates early-motor complications that appeared less than one year after levodopa initiation, including dyskinesias affecting (A) the trunk, the lower limbs, (B) and the gait. (C) Motor fluctuations are also illustrated with a freezing phenomenon.
Table 1
Summary of data regarding response to levodopa in patients with RAB39B X-linked Parkinsonism.
| REF. | MUTATION | SEX | AGE AT SYMPTOM’S ONSET | RESPONSE TO L-DOPA1 | LDIC² | DELAY TO LDIC | DBS |
|---|---|---|---|---|---|---|---|
| [19, 20] | Point mutation c.503C>A [p.Thr168Lys] | 13M and 1F | 10–20’s | None (3/3) | Yes | NR | NR |
| [8] | All gene deletion 45kb | M | Late childhood | NA | NA | NA | NR |
| [8] | All gene deletion 45kb | M | 38y | Yes | No | NA | NR |
| [8] | All gene deletion 45kb | M | 44y | Yes | Yes | NR | NR |
| [21] | Nonsense mutation c.557G.Ain exon 2 [p.Trp186stop] | M | 39y | Good | Yes (MF, dyskinesia, and limb dystonia) | 8 years | Not performed |
| [22] | Missense mutation (c.574G > A; p.G192R) | 5M | 29y–31y–48y–50y–53y | Yes (4/4) | Yes (3/4 – dyskinesia) | NR | NR |
| [22] | Missense mutation (c.574G > A; p.G192R) | 2F | 55y–57y | Yes (2/2) | Yes (1/2 dyskinesia) | NR | NR |
| [23] | Frameshift mutation c. 536dupA (p.E179fsX48) | M | 10y | Partial | NR | NA | NR |
| [23] | Frameshift mutation c. 536dupA (p.E179fsX48) | M | 12y | None | NR | NA | NR |
| [24] | Frameshift variant c.137dupT | M | 11y | Good | No | NA | NR |
| [24] | Frameshift variant c.137dupT | M | 60y | Good | Yes (dyskinesia) | NR | NR |
| [24] | Deletion variant c.371delA | M | 44y | Good | No | NA | NR |
| [25] | Hemizygous single base pair deletion c.432delA | M | 29y | Partial | NR | NA | NR |
[i] 1 Number of patients bracketed. 2 Levodopa induced complications with number of patients and type of complication bracketed. F: Female; LDIC: Levodopa induced complications; M: Male; MF: Motor Fluctuations; NA: Not applicable; NR: Not reported.