Genetics
Autosomal Inheritance
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Get access- Autosomal dominant: a monogenetic disorder manifests in the heterozygous state
- Represent more than 50% of all mendelian phenotypes
- Inheritance usually from just one parent who is heterozygous
- M=F
- Phenotype can occur in all generations
- Exceptions:
- A fresh mutation occurs in a normal parent
- The disorder is not expressed (so-called non-penetrant)
- Homozygotes tend to be more severely affected (Huntington’s being an exception)
Autosomal recessive: disorders that are only expressed when both abnormal genes are present (homozygous)
- Account for a third of all mendelian phenotypes
- Typically due to the mating of two carriers
Consanguinity between parents of an affected person is more likely especially if the gene is rare
- M=F