Pellagra is caused by -
Ans. is 'a' i.e., Hartnup's diseaseHartnup's disease* It is a defect of neutral aminoacid transporter which is specific for tryptophan. This transporter is responsible for tryptophan absorption along intestine as well as tryptophan reabsorption across renal tubules.* When tryptophan is not absorbed, tryptophan can not be converted into niacin (Niacin is endogenously synthesised from tryptophan). Hence it presents as pellagra.* As the transporter is also related to tryptophan reabsorption along renal tubules, tryptophan will be lost in the urine. Hence it presents as aminoaciduria.
Vitamins and Minerals
Hartnup's disease
Cystinuria
Cystinosis
Type I Tyrosinemia
Hartnup's disease