We herein report a case of aceruloplasminemia in a 27-year-old man who had a 10-year history of diabetes mellitus. The patient developed a convulsion, most likely as a result of hypoglycemia. Unexpectedly, this episode left him in a prolonged state of unconsciousness, which necessitated neurological testing and imaging. Brain MRI showed bilateral hypo-intensities in the basal ganglia and thalamus. Molecular analysis revealed a novel splicing mutation in the ceruloplasmin (CP) gene that would result in the skipping of exon 3 during transcription. This case suggests that diabetes associated with aceruloplasminemia can become manifest in the teens.