Diseases or traits that are the result of a single mutant gene that has a large effect on phenotype, and that are inherited in simple patterns similar to, or identical with, those described by Gregor Mendel. Modes of inheritance reveal whether a Mendelian trait is dominant or recessive and whether the gene that controls it is carried on an autosome or a sex chromosome. Examples of Mendelian diseases: cystic fibrosis, sickle cell disease, Huntington Disease, and hemophilia.