Which of the following is the incorrect pair

Options

A. `{:(" Disease Symptom"),("Phenylketonuria Urine turns black on exposure to air"):}`
B. `{:(" Disease Symptom"),("Down's syndrome Physical and mental retardation"):}`
C. `{:(" Disease Symptom"),("Klinefelter's syndrome Sterile males"):}`
D. `{:(" Disease Symptom"),("Turner's syndrome Sterile females"):}`

Answer

A

Explanation

Phenyketonuria is an inherited error of metabolism caused by the deficiency if enzyme phenylalanine hydrozylase. This enzyme is required for the conversion of pheylalanine into tyrosine. Thus, deficiency of this enzyme leads of over production of phenylalanine and its conversion to phenyl pyruvic acid and other derivatives, whicg accumulate in cerebrospinal fluid leading to severe mental retardation, and also get excreted in urine due to poor absorption by kidney. The disease is inherited as an autosomal recessive trait. Alkaptonuria is the disease in which urine turns black on exposure to air.