Autosomal dominant

Definition

Autosomal dominant is a pattern of inheritance where only one copy of a mutated gene from one parent is sufficient to cause a genetic disorder. This means that an individual has a 50% chance of inheriting the condition from an affected parent, regardless of gender. Autosomal dominant traits can manifest in the phenotype of individuals, meaning they can be visibly expressed in their physical characteristics or health conditions.

5 Must Know Facts For Your Next Test

1. In autosomal dominant inheritance, the presence of just one mutated allele can lead to the expression of the associated trait or disorder.
2. Common examples of autosomal dominant disorders include Huntington's disease, Marfan syndrome, and familial hypercholesterolemia.
3. Individuals with autosomal dominant conditions may have an affected parent, but new mutations can also arise, leading to cases without a family history.
4. This inheritance pattern can affect males and females equally since it is located on non-sex chromosomes (autosomes).
5. The severity of symptoms can vary widely among individuals with the same autosomal dominant condition, even within the same family.

Review Questions

• How does autosomal dominant inheritance affect the probability of offspring inheriting a genetic disorder?
  • In autosomal dominant inheritance, if one parent is affected by a genetic disorder, there is a 50% chance that each offspring will inherit the mutated gene. This probability remains constant for each child regardless of whether the first child inherits the condition or not. This type of inheritance means that even if only one parent carries the mutation, it can still significantly impact the family by passing on the disorder to multiple children.
• Discuss the implications of having an autosomal dominant condition for family planning and genetic counseling.
  • For individuals with an autosomal dominant condition, understanding the inheritance pattern is crucial for family planning. Genetic counseling can provide valuable insights into the risks of passing on the disorder to future children. Couples may consider options such as prenatal testing or assisted reproductive technologies to manage these risks. Additionally, knowledge of family history and potential symptoms can help families prepare for possible outcomes and seek early interventions when necessary.
• Evaluate how varying expressions of autosomal dominant traits within a single family could influence medical treatment and management strategies.
  • The varying expressions of autosomal dominant traits within a family can complicate medical treatment and management strategies. Different individuals may present with different severities or manifestations of the same condition, requiring tailored approaches to healthcare. For example, some may require intensive monitoring or early interventions, while others may lead relatively normal lives with minimal symptoms. Recognizing this variability is essential for healthcare providers to create effective, personalized management plans and to communicate effectively with affected families about their unique situations.

Related terms

Homozygous: A genetic condition where an individual has two identical alleles for a particular gene, one inherited from each parent.

Phenotype: The observable physical or biochemical characteristics of an organism, determined by both genetic makeup and environmental influences.

Genotype: The genetic constitution of an individual, referring specifically to the alleles present at a given locus.