Biotinidase deficiency (BTD) is a rare autosomal recessive disease associated with a mutation in the BTD gene. Clinically it manifests as a neurocutaneous syndrome, sometimes associated with respiratory and immunological disorders. Timely identification of this inborn error of metabolism (IEM) remains a major challenge due to its variable clinical presentation. Early diagnosis can improve the patient's prognosis and decrease morbidity and mortality. We describe the case of a patient with BTD with partial enzyme deficiency, with severe clinical manifestations.