A 25 year old male presented with pigmentation of nose and pinna. After voiding, his urine becomes dark. His spine is most likely to show-

Ans. is 'd' i.e., Calcification of disc Clinical features of the patient suggests the diagnosis of AlkaptonuriaClinical problems arise from degenerative changes in articular cartilage with the development of ochronotic arthritis and from calcification of intervertebral discsOther clinical features areScleral pigmentation (Foci of grey brown pigments)Generalized darkening of concha, anthelix and finally helixPigmentation of heart valves, larynx, and tympanic membranes develops.Urine turns black on exposure