What change will be seen in vertebral column in ochronosis-

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.# Benedict's test is strongly positive in urine and so is the ferric chloride (FeClyl test. Benedict's reagent gives a greenish brown precipitate with brownish black supematent. Feh ling's reagent (FeClj gives blue green colour.