A family history of a genetic condition. Pedigree charts show the inheritance of a trait in a...
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Transcript of A family history of a genetic condition. Pedigree charts show the inheritance of a trait in a...
![Page 1: A family history of a genetic condition. Pedigree charts show the inheritance of a trait in a family. It usually tracks a particular trait or disease.](https://reader036.fdocuments.in/reader036/viewer/2022062518/56649f345503460f94c50f03/html5/thumbnails/1.jpg)
A family history of a genetic condition
![Page 2: A family history of a genetic condition. Pedigree charts show the inheritance of a trait in a family. It usually tracks a particular trait or disease.](https://reader036.fdocuments.in/reader036/viewer/2022062518/56649f345503460f94c50f03/html5/thumbnails/2.jpg)
Pedigree charts show the inheritance of a trait in a family.
It usually tracks a particular trait or disease through several generations.
![Page 3: A family history of a genetic condition. Pedigree charts show the inheritance of a trait in a family. It usually tracks a particular trait or disease.](https://reader036.fdocuments.in/reader036/viewer/2022062518/56649f345503460f94c50f03/html5/thumbnails/3.jpg)
A marriage with five children, two daughters and three sons. The eldest son is affected by the condition.
Eldest child Youngest child
offspring
Normal MaleAffected Male
Normal Female
Affected Female
Marriage
Carrier
![Page 4: A family history of a genetic condition. Pedigree charts show the inheritance of a trait in a family. It usually tracks a particular trait or disease.](https://reader036.fdocuments.in/reader036/viewer/2022062518/56649f345503460f94c50f03/html5/thumbnails/4.jpg)
A pedigree chart of a family showing 20 individuals
![Page 5: A family history of a genetic condition. Pedigree charts show the inheritance of a trait in a family. It usually tracks a particular trait or disease.](https://reader036.fdocuments.in/reader036/viewer/2022062518/56649f345503460f94c50f03/html5/thumbnails/5.jpg)
Generations are identified by Roman numerals
I
II
III
IV
![Page 6: A family history of a genetic condition. Pedigree charts show the inheritance of a trait in a family. It usually tracks a particular trait or disease.](https://reader036.fdocuments.in/reader036/viewer/2022062518/56649f345503460f94c50f03/html5/thumbnails/6.jpg)
Individuals in each generation are identified by Arabic numerals numbered from the left
Therefore the affected individuals are II3, IV2 and IV3
I
II
III
IV
![Page 7: A family history of a genetic condition. Pedigree charts show the inheritance of a trait in a family. It usually tracks a particular trait or disease.](https://reader036.fdocuments.in/reader036/viewer/2022062518/56649f345503460f94c50f03/html5/thumbnails/7.jpg)
1. Determine if the pedigree chart shows an autosomal or X-linked disease.
If most of the males in the pedigree are affected the disorder is X-linked
If it is a 50/50 ratio between men and women the disorder is autosomal.
![Page 8: A family history of a genetic condition. Pedigree charts show the inheritance of a trait in a family. It usually tracks a particular trait or disease.](https://reader036.fdocuments.in/reader036/viewer/2022062518/56649f345503460f94c50f03/html5/thumbnails/8.jpg)
Is it Autosomal or X-linked?
![Page 9: A family history of a genetic condition. Pedigree charts show the inheritance of a trait in a family. It usually tracks a particular trait or disease.](https://reader036.fdocuments.in/reader036/viewer/2022062518/56649f345503460f94c50f03/html5/thumbnails/9.jpg)
Autosomal
![Page 10: A family history of a genetic condition. Pedigree charts show the inheritance of a trait in a family. It usually tracks a particular trait or disease.](https://reader036.fdocuments.in/reader036/viewer/2022062518/56649f345503460f94c50f03/html5/thumbnails/10.jpg)
2. Determine whether the disorder is dominant or recessive.
If the disorder is dominant, one of the parents must have the disorder.
If the disorder is recessive, neither parent has to have the disorder because they can be heterozygous.
![Page 11: A family history of a genetic condition. Pedigree charts show the inheritance of a trait in a family. It usually tracks a particular trait or disease.](https://reader036.fdocuments.in/reader036/viewer/2022062518/56649f345503460f94c50f03/html5/thumbnails/11.jpg)
Dominant or Recessive?
![Page 12: A family history of a genetic condition. Pedigree charts show the inheritance of a trait in a family. It usually tracks a particular trait or disease.](https://reader036.fdocuments.in/reader036/viewer/2022062518/56649f345503460f94c50f03/html5/thumbnails/12.jpg)
Dominant
![Page 13: A family history of a genetic condition. Pedigree charts show the inheritance of a trait in a family. It usually tracks a particular trait or disease.](https://reader036.fdocuments.in/reader036/viewer/2022062518/56649f345503460f94c50f03/html5/thumbnails/13.jpg)
Dominant or Recessive?
![Page 14: A family history of a genetic condition. Pedigree charts show the inheritance of a trait in a family. It usually tracks a particular trait or disease.](https://reader036.fdocuments.in/reader036/viewer/2022062518/56649f345503460f94c50f03/html5/thumbnails/14.jpg)
Recessive
![Page 15: A family history of a genetic condition. Pedigree charts show the inheritance of a trait in a family. It usually tracks a particular trait or disease.](https://reader036.fdocuments.in/reader036/viewer/2022062518/56649f345503460f94c50f03/html5/thumbnails/15.jpg)
Pedigrees are family trees that explain your genetic history.
Pedigrees are used to find out the probability of a child having a disorder in a particular family.
To begin to interpret a pedigree, determine if the disease or condition is autosomal or X-linked and dominant or recessive.