Question

Write short notes on:

Polygenic disorders.

Answer 1

• Polygenic disorders are caused due to mutations in more than one gene. 
• In most such cases, their severity increases due to effects of environmental factors on the foetus.’ 
• Common examples of such disorders are cleft lip, cleft palate, constricted stomach, spina bifida (a defect of the spinal cord), etc. Besides diabetes, blood pressure, heart disorders, asthma and obesity are also polygenic disorders. 
• Polygenic disorders do not strictly follow Mendel’s principles of heredity. 
• These disorders arise from a complex interaction between environment, life style and defects in several genes.