Title: How Genetic Disorders Are Inherited
Headings: How Genetic Disorders Are Inherited
How Genetic Disorders Are Inherited
Understanding Patterns of Inheritance
Patterns of Inheritance
Autosomal Dominant
Autosomal Recessive
X-Linked Dominant
X-Linked Recessive
Mitochondrial
Other Inheritance Patterns
Y-Linked Disorders
Codominance

Content: Two primary factors influence the likelihood a person will inherit a genetic disorder: Whether one copy of the mutated gene (from either parent) is passed down or whether two copies (one from both parents) are passed down
Whether the mutation is on one of the sex chromosomes (X or Y) or on one of 22 other pairs of non-sex chromosomes (called autosomes)
Learn How and Why Chromosomal Abnormalities Occur
Autosomal Dominant
In autosomal dominant disorders, only one copy of a mutated gene is necessary and males and females are equally likely to be affected. Children who have a parent who has an autosomal dominant disorder have a 50% risk of inheriting the disorder. Sometimes, however, these disorders result from a new mutation and happen in people with no family history. 4 ﻿ Examples of autosomal dominant disorders include Huntington's disease and Marfan syndrome. Genetic Testing for Huntington's Disease
Autosomal Recessive
In autosomal recessive disorders, both copies of a mutated gene—one from each parent—are present. A person with only one copy will be a carrier. Carriers will not have any signs or symptoms of the disorder. They can, however, pass the mutation to their children. If families in which both parents carry the mutation for an autosomal recessive disorder, the odds of the children having the disorder are as follows: