Certain conditions can be passed down through dominant inheritance. Dominant inheritance means that a mutation in a gene can cause symptoms in a person even if the second copy of that gene is normal.
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Dominant Inheritance
Our genes can be passed down, or inherited, from our mom and dad in several different ways. One way is called dominant inheritance.
Dominant inheritance means that a mutation in a gene can cause symptoms in a person, even if the second copy of that same gene is normal. Dominant inheritance causes “dominant conditions.”
One copy of each gene comes from mom and the other from dad.
A person can either inherit a dominant condition from a parent, or they can be the first person to have the condition in their family if the mutation arose as a new, or “de novo,” change in them.
You might be able to recognize dominant inheritance in your family because you see a condition being passed from one generation to the next. For example, you know that your mom, you, and your child all have hearing loss.
If we think about a dominant condition being passed from one generation to the next, you might be wondering why some people are affected and some people are not. This is because a parent with a dominant condition can pass on either their gene with the mutation, or their normal gene.
If a child gets the mutation from their parent they will, in general, be affected with similar features. However, they won’t always be exactly the same — individual features and severity may vary.
A child who inherits the normal copy of the gene will not be affected.
Anyone affected with a dominant condition has a 50% chance in each pregnancy to pass it on. It is very important to recognize that a parent does not control which gene copy gets passed on to their child.
In a de novo dominant condition, the parents have very little risk of having another child affected. However, the person with the condition will now have a 50% chance of passing it on to their children.