The objectives of this study are to assess the tolerability, safety and pharmacokinetic parameters of Genz-682452 in healthy adult males, in two parts.

Part 1 (GZFD00111TDU12766): double-blind, randomized, placebo-controlled, sequential ascending single dose study;

Part 2 (GZFD00211FED12767): open-label, randomized, 2-sequence, 2-period, 2-treatment crossover study with a minimum wash-out period; to obtain preliminary information on the pharmacokinetics, tolerability and safety of Genz-682452 after single oral doses in fed and fasted conditions.

Subjects are not allowed to participate in more than 1 part of the study.

Inclusion Criteria:

• Body weight between 50.0 and 100.0 kg, inclusive, body mass index between 18.0 and 32.0 kg/m^2, inclusive.
• Certified as healthy by a comprehensive clinical assessment (detailed medical history and complete physical examination).

Exclusion Criteria:

• Any history or presence of clinically relevant cardiovascular, pulmonary, gastrointestinal, hepatic, renal, metabolic, hematological, neurological, osteomuscular, articular, psychiatric, systemic, ocular, or infectious disease, or signs of acute illness.
• Frequent headaches and/or migraine, recurrent nausea and/or vomiting.
• Blood donation, greater than 100 mL, within 2 months before inclusion.
• Presence or history of drug hypersensitivity, or allergic disease diagnosed and treated by a physician.
• History or presence of drug or alcohol abuse.
• Unable to stop smoking cigarettes during the study.
• Excessive consumption of beverages containing xanthine bases.