Hartnup disease

Hartnup disease is a rare autosomal recessive disorder in which a transport protein necessary for the absorption of neutral amino acids is defective. So, Hartnup disease is associated with impaired absorption of neutral amino acids such as tryptophan, which is responsible for synthesizing vitamin B3. This results in vitamin B3 deficiency, presenting symptoms of pellagra ( diarrhea, dermatitis, dementia), cerebellar ataxia, and seizures.