Learning Objectives

• Recognise and recall the cause and clinical features of the major autosomal dominant disorders
• Recognise and create an autosomal dominant pedigree, and describe features of autosomal dominant inheritance
• Explain the rationale and testing strategy for presymptomatic testing/ surveillance of a family member at risk for an autosomal dominant disorder
• Describe the principles of expression, anticipation and penetrance in genetic disorders
• Recognise patient scenarios that require genetic counselling; and demonstrate empathy and professionalism during genetic counselling, according to the severity of the prognosis
• Explain in simple terms to a patient how autosomal dominant disorders are inherited

Gene Expression & Penetrance

• what is expression?
• what can influence the level of expression?
• what is penetrance?
• what is partial vs full penetrance?
• how are mutated alleles classified in terms of their functional effect?

Autosomal Dominant Disorders

• what are the features of autosomal dominant inheritance?
• what are expansion repeat disorders?
• how are diseases inherited according to Knudson's two-hit hypothesis?
• how is pre-symptomatic testing of family members at risk of an AD disorder done?
• why is gene therapy better for recessive traits?