<prompt> What change will be seen in vertebral column in ochronosis-Calcification of discBamboo spineIncreased disc spaceNone  <response>: Ans. is a i.e., Calcification of discAlkaptonuria It is due to deficiency of homogentisate oxidase. As a result homogentisic acid homogentisate is excreted execessively in urine, There are three important characteristic features in alkaptonuria-Urine becomes dark after being exposed to air. It is due spontaneous oxidation of homogentisate into benzoquinone acetate, which polvmerse to form black-brown pigment alkapton which imparts a characteristic black-brown colour to urine.Alkapton deposition occurs in sclera, ear, nose, cheeks and intervertebral disc space. A condition called ochronosis. There may be calcification of intervertebral discs.Onchronosis arthritis affecting shoulder, hips, knee. Benedicts test is strongly positive in urine and so is the ferric chloride FeClyl test. Benedicts reagent gives a greenish brown precipitate with brownish black supematent. Feh lings reagent FeClj gives blue green colour. 