A 40-year-old woman presents with progressive palmoplantar pigmentation. X-ray spine shows calcification of IV disc. On adding benedicts reagent to urine, it gives greenish brown precipitate and blue-black supernatant fluid. What is the diagnosis?
Ans. B. AlkaptonuriaAlkaptonuriaAutosomal Recessive disorder is due to a deficiency of Homogentisic Acid Oxidase1st inborn error detectedBelongs to Garrod's Tetrad Biochemical DefectHomogentisate Oxidase deficiency leads to accumulation of Homogentisic Acid (Homogentisate) which polymerises to form Alkaptone bodies.Clinical PresentationNormal Life till 3rd or 4th decade.Urine Darkens on standing is the only manifestation in children.In adults Ochronosis-Alkaptone Bodies in Intervertebral Disc, cartilage of nose, pinna, etc.Laboratory DiagnosisAlkalanisation increase darkening of urine.Benedicts test positive in urine because homogentisic acid is reducing agent.Ferric Chloride test positiveSilver Nitrate Test positive.No Mental RetardationTreatmentNew Drug is Nitisinone which inhibit para Hydroxyl Phenyl Pyruvate hydroxylase which prevent the accumulation of homogentisic acid.Symptomatic Treatment.
Phenyl ketonuria
Alkaptonuria
Tyrosinemia type 2
Argininosuccinic aciduria
Proteins and Amino Acids