Which genetic condition causes foul-smelling urine and may result in neurological abnormalities?

• A. Albinism
• B. Phenylketonuria
• C. Sickle cell disease
• D. Tay-Sachs disease

Answer: (B)

Phenylketonuria (PKU) is a genetic condition characterized by the inability to metabolize phenylalanine, an amino acid found in many protein-containing foods. This inability is due to a deficiency in the enzyme phenylalanine hydroxylase. When phenylalanine accumulates in the body, it can lead to a variety of health issues, including neurological abnormalities if left untreated.

One of the distinct symptoms of PKU is the presence of foul-smelling urine, which is caused by the accumulation of phenylacetate—one of the byproducts of excess phenylalanine metabolism. If individuals with PKU are not placed on a strict low-phenylalanine diet from a young age, they can suffer severe cognitive impairments and other neurological issues due to the toxic effects of accumulated phenylalanine in the nervous system.

The other conditions listed do not share these specific symptoms or effects. Albinism primarily affects pigmentation and vision, sickle cell disease mainly involves issues related to blood cells and pain crises, and Tay-Sachs disease is a neurodegenerative condition associated with specific genetic mutations that lead to a build-up of GM2 gangliosides in the brain, but it does not result in foul-sm