Inclusion Criteria:  ADCY5 mutation carriers Age > 15 years old and 3 months Informed consent from the patient or/ and a legal representative when appropriate Affiliated with a social security system or beneficiary of such a regime or by waiver from CPP ( french ethic committee) for patients outside the European union ( EU) daily caffeine consumer  Exclusion Criteria:  Hypersensitivity to caffeine or to xanthine derivatives Heart condition contraindicating coffee intake Liver failure Impaired comprehension interfering with an informed consent Positive pregnancy test for women of childbearing potential Patient treated by Enoxacin, Ciprofloxacin, Norfloxacin (Noroxin), Cimetidine, Phenytoin β-adrenergic drugs (β2 mimetics) at inclusion.