Editing Inverted repeat (section)

=== Antithrombin deficiency from a point mutation ===
Imperfect inverted repeats can lead to [[mutation]]s through intrastrand and interstrand switching.<ref name=bissler />  The [[antithrombin]] III gene's coding region is an example of an imperfect inverted repeat as shown in the figure on the right.
The [[stem-loop]] structure forms with a bump at the bottom because the G and T do not pair up. A strand switch event could result in the G (in the bump) being replaced by an A which removes the "imperfection" in the inverted repeat and provides a stronger stem-loop structure. However, the replacement also creates a [[point mutation]] converting the GCA codon to ACA. If the strand switch event is followed by a second round of [[DNA replication]], the mutation may become fixed in the [[genome]] and lead to disease. Specifically, the [[missense mutation]] would lead to a defective gene and a deficiency in antithrombin which could result in the development of [[venous thromboembolism]] (blood clots within a vein).<ref name=bissler />
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[[File:Collagen-gene-strand-switch.gif|frame|left]]<!--|A strand switch event perfects the inverted repeat with a T-insertion in the stem region of the collagen gene and results in a frameshift mutation.-->