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Familial paroxysmal dystonic choreoathetosis revisited
D T Schloesser1, T N Ward, P D Williamson
1Department of Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA.
Summary
Familial paroxysmal dystonic choreoathetosis (PDC) shows variable expression. Exertional cramping may be an incomplete form of PDC, more common in men, while typical PDC presents in women.
Area of Science:
- Neurogenetics
- Movement Disorders
Background:
- Familial paroxysmal dystonic choreoathetosis (PDC) is a rare inherited movement disorder.
- Understanding its genetic basis and phenotypic variability is crucial for diagnosis and management.
Observation:
- A case of familial PDC was documented using video/EEG monitoring.
- The proband's father exhibited exertional cramping, suggesting it as a potential "forme fruste" of PDC.
- Affected family members included women with typical PDC and men with isolated exertional cramping.
Findings:
- Two women experienced prolonged exertion-induced PDC spells, distinct from the intermediate form.
- Exertional cramping in male family members may represent variable gene expression.
- Exercise-induced PDC, in both intermediate and typical forms, appears to manifest more frequently in women.
Implications:
- This case supports the hypothesis of exertional cramping as an incomplete manifestation of the PDC gene.
- The findings suggest sex-based predilection in the expression of exercise-induced PDC.
- Further research into the genetics of PDC and its variable expressivity is warranted.
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