Question

Which disorder is known as “Inborn Error of Metabolism”? Mention its cause and any one symptom. Name the harmful compounds formed.

Answer 1

• Disorder: Phenylketonuria (PKU), an inborn error of metabolism.
• Cause: Deficiency/absence of the enzyme phenylalanine hydroxylase (so phenylalanine cannot be converted to tyrosine).
• One symptom: Intellectual disability (developmental delay) may also have seizures and a “musty” body/urine odour.
• Harmful compounds formed: Phenylketones such as phenylpyruvate (phenylpyruvic acid), phenylacetate (phenylacetic acid) and phenyllactate (phenyllactic acid).