The given below clinical features occurs due to deficiency of:

Ans. (A)) Tryptophan(Ref: Harpers Illustrated Biochemistry 31st Ed; Page No- 562)The image provided is characteristic of Casals necklace, seen in pellagra and indicates a deficiency of Tryptophan.Pellagra can occur due to:Vitamin B3 (Niacin): Niacin is derived from tryptophan and needs vitamin B2 and B6 for its synthesis.Hartnups disease (Tryptophan malabsorption)#In Hartnups disease, defective membrane transport tryptophan across PCT and enterocytes leads to malabsorption of tryptophan. This causes a deficiency of tryptophan.Carcinoid syndrome: Over production of serotonin leads to diversion of tryptophan from NAD+ pathway.Vitamin B6 deficiency: Defective Kynureninase that leads to defective synthesis of Niacin.Vitamin Deficiency DisordersFat soluble vitaminFat soluble vitaminFunctionsDeficiency syndromesVitamin A* Maintenance of specialized epithelia* Maintenance of resistance to infection* A component of visual pigment * Blindness* Night Blindness* Vulnerability to infection, particularly measles* Squamous epithelia* XerophthalmiaVitamin D* Helps in intestinal absorption of calcium and phosphorous and mineralization of bones* Osteomalacia in adults* Rickets in childrenVitamin E* It is the Major antioxidant; scavenges free radicals* Retinopathy* Myopathy* Age related macular degeneration* Peripheral neuropathy* Spinocerebellar degeneration* Testicular atrophyVitamin K* Cofactor in hepatic carboxylation of procoagulants - factors II, VII, IX and X and protein C and protein S* Bleeding diathesisWater soluble vitaminsWater soluble vitaminFunctionsDeficiency syndromesVitamin B1(thiamine)* Acts as pyrophosphate, is coenzyme indecarboxylation reactions* Korsakoff syndrome* Wernicke syndrome (Most important note it)* Dry and wet beriberiVitamin B2(riboflavin)* Cofactors for many enzymes in intermediary metabolism* Converted to coenzymes flavin mononucleotide and flavin adenine dinucleotide* Seborrheic dermatitis* Dermatitis* Stomatitis* Cheilosis* Moeller's glossitis* Ariboflavinosis* Corneal vascularizationVitamin B6(pyridoxine)* Coenzymes in many intermediary reactions* Dermatitis* Glossitis* Cheilosis* Peripheral neuropathyVitamin B12* Maintenance of myelination of spinal cord tracts* Required for normal folate metabolism and DNA synthesis.* Combined system disease (megaloblastic pernicious anemia and degeneration of posterolateral spinal cord tracts)Vitamin C* Hydroxylation of collagen* Serves in many oxidation reduction reactions* ScurvyFolate* Essential for transfer and use of 1-carbon units in DNA synthesis* Neural tube defects* Megaloblastic anemiaPantothenic acid* Incorporated in coenzyme A* No experimental syndrome recognizedBiotin* Cofactor in carboxylation reactions* No clearly defined clinical syndrome