Autosomal dominant inheritance Flashcards
(13 cards)
What is the frequency of autosomal dominant diseases in the population?
Approximately 1 in every 200 individuals
Most common autosomal dominant diseases have gene frequencies around 0.001.
What is the typical parental combination for producing affected offspring in autosomal dominant inheritance?
Union of an unaffected parent with an affected heterozygote
In a Punnett square, what is the probability that an affected parent passes on the disease allele?
0.5
What is the expected ratio of heterozygotes expressing the disease to unaffected homozygotes in autosomal dominant inheritance?
1:1
What is postaxial polydactyly?
Presence of an extra digit next to the fifth digit
How is the trait of postaxial polydactyly inherited?
As an autosomal dominant trait
What are the key characteristics of autosomal dominant inheritance?
- Vertical transmission of the disease phenotype
- Lack of skipped generations
- Approximately equal numbers of affected males and females
Is father-to-son transmission of the disease gene required for autosomal dominant inheritance?
No, but its presence rules out some other modes of inheritance
What is the recurrence risk for children if one parent is affected by an autosomal dominant disease?
1/2
Does the recurrence risk change based on previous children being affected or unaffected?
No, it remains 1/2 regardless
What concept explains that each birth is an independent event in autosomal dominant inheritance?
Law of independence
What is the significance of the law of independence in genetic risk?
The risk remains constant regardless of previous births
What aspect of communication regarding genetic risks is commonly misunderstood by the lay population?
The independence of each birth and its associated risk
