Question

The disorders such as alkaptonuria and phenylketonuria are referred to as ?

• A. Acquired disease
• B. Congenital disease
• C. Infectious disease
• D. All of the above

Answer 1

Answer: (B)

Congenital disease

The disorders that develop post-fetally after birth of individuals are acquired disorders while a congenital disorder is present at birth.

Infectious diseases are caused by pathogens such as bacteria, viruses, fungi or parasites and can be passed from person to person. The disorders such as alkaptonuria and phenylketonuria are referred to as congenital disorders since these are the inborn errors in metabolism which means that the individual is borne with these defects. They are not acquired after birth, hence they are not acquired disorders. Further, these disorders can not be passed from one person to other with physical touch. They are inherited genetically only. Person with phenylketonuria has defective gene for phenylalanine hydroxylase which breaks down an essential amino acid called phenylalanine and, hence, they accumulate phenylalanine in their body. Alkaptonuria is characterised by inability to process the amino acids phenylalanine and tyrosine caused by mutation in the gene for the enzyme homogentisate 1, 2-dioxygenase.