List of Mendelian traits in humans

In Mendelian inheritance, a child receiving a dominant allele from either parent will have the dominant form of the trait. Only those that received the recessive allele from both parents present with the recessive phenotype. Purely Mendelian traits are a tiny minority of all traits, since most phenotypic traits exhibit incomplete dominance, codominance, and contributions from many genes.

Attached earlobes were previously believed to be a recessive phenotype.

Hitchhiker's thumbs

The recessive phenotype may theoretically skip any number of generations, lying dormant in heterozygous "carrier" individuals until they have children with someone who also has the recessive allele and both pass it on to their child.

Examples

These traits include:

• Ability to taste phenylthiocarbamide (dominant)
• Ability to smell (bitter almond-like) hydrogen cyanide
• ACHOO syndrome (dominant)
• Albinism (recessive)
• Brachydactyly (Shortness of fingers and toes)
• Wet (dominant) or dry (recessive) earwax
• Face freckles (dominant)
• Huntingtons Disease (dominant)
• Blood type

Traits previously believed to be Mendelian

Some traits were previously believed to be Mendelian, but their inheritance is (probably) based on more complex genetic models^{[citation needed]}, possibly involving more than one gene. These include ^[1]:

• Eye color
• Hair color
• Morton's toe
• Tongue rolling
• Widow's peak (allele)
• Hitchhiker's thumb (recessive)
• Cleft chin (dominant)
• Dettached (dominant) or attached (recessive) earlobes

See also

• Heritability
• Human genetic variation
• Human genetic clustering

References

1. ^ http://udel.edu/~mcdonald/mythintro.html

External links

• OMIM Online Mendelian Inheritance in Man