Mendelian traits in humans are human traits that are substantially influenced by Mendelian inheritance. Most – if not all – Mendelian traits are also influenced by other genes, the environment, immune responses, and chance. Therefore no trait is purely Mendelian, but many traits are almost entirely Mendelian, including canonical examples, such as those listed below. Purely Mendelian traits are a minority of all traits, since most phenotypic traits exhibit incomplete dominance, codominance, and contributions from many genes. If a trait is genetically influenced, but not well characterized by Mendelian inheritance, it is non-Mendelian.

Examples

<!--== Non-Mendelian traits == # Physical Mendelian traits # Blood group inheritance Blood from the ABO system is not mendelian because multiple alleles are required from each parent (co-dominant). However the Rhesus factor is truly mendelian because only one allele is inherited from each parent. Rh factor is an antigen on the red blood cell of many people's blood. A positive Rh factor is dominant (presence of antigen) and a negative Rh is recessive (lack of antigen). Blood groups that children may inherit from their parents. # Non-Mendelian traits Most traits (including all [complex traits](https://bliptext.com/articles/complex-traits)) are non-mendelian. Some traits commonly thought of as Mendelian are not, including: