You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is The given below clinical features occurs due to deficiency of: and explain in detail?
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