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Autosomal dominant inheritance |
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Everybody has two copies of each of their genes, which are inherited from their parents.
One copy is inherited from the father and the other from the mother (there are about 60,000 different
genes, and two copies of each).
In autosomal dominant inheritance, a single copy of an abnormal gene is enough for clinical signs of
the disease to appear. This is because both the healthy gene and the abnormal gene are equally active.
In this inheritance pattern, both males and females are affected equally and with the same degree of severity.
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An affected person has a 50% risk of transmitting the abnormal gene to his
children. The risk that healthy parents who have an affected child will have another
affected child is low, as in most such cases a new mutation has arisen in the ovum
or sperm cell that formed the child. An example of a disease transmitted by
autosomal dominant inheritance is achondroplasia (one of the more common forms of
short stature).
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