Obsessive-Compulsive Symptoms as aManifestation of Homocystinuria

Homocystinuria is a rare autosomal recessive metabolic disorder due to a defect in the cystathionineβ-synthase (CBS) that leads tohigh homocysteine plasma levels. Psychiatric symptoms secondary to homocystinuria have been described in the literature;however, there is a lack of information about obsessive-compulsive symptoms correlated to this disorder. We describe the caseof a 39 years old man, diagnosed with homocystinuria in childhood, with no previous psychiatric history that presentedobsessive-compulsive disorder (OCD) like symptoms, as a manifestation of homocystinuria. This case underlines theimportance for a psychiatrist to explore medical nonpsychiatric history, especially when presentation is abrupt, atypical, or intreatment-resistant cases.