Genes – The Unit of Hereditary Information

Genes – The Unit of Hereditary Information
Introduction
Archibald Garrod discovered in 1902, that certain diseases were more prevalent among some families and were inherited as a recessive Mendelian trait.
Alkaptonuria
Alkaptonuria is a disease in which the urine contained a substance called “Alkapton” now known as “Homogentisic acid” which was immediately oxidizes to black when exposed to the air.
Causes

• He suggested that this disease occurred due to absence of an enzyme, which could break the “Alkapton” down to other products so it would not build up in the urine.
• He proposed that the condition was “An inborn error of metabolism” which is occurring due to changes in the hereditary information, which must have occurred in one of the ancestors of the affected families.

Conclusion
He concluded that the inherited disorders might reflect enzyme deficiencies.