Types of Inheritance
Monogenetic or Mendelian inheritance, or single gene inheritance, is a result of mutations or changes occurring in the DNA sequence of one gene. There are more than 6,000 genetic disorders which are classified as single-gene, and these affect about one out of 200 babies born. These are referred to as monogenetic disorders. Some examples include cystic fibrosis, Marfan syndrome, hemochromatosis, sickle cell anemia and Huntington's disease. Monogenetic disorders have recognizable inheritance patterns, including autosomal recessive, autosomal dominant and X-linked.
Multifactorial Inheritance is also referred to as polygenic or complex inheritance and results from a combination of multiple gene mutations and environmental factors. Examples include heart disease, Alzheimer's disease, diabetes, obesity, high blood pressure, arthritis and cancer.
Chromosomal means a chromosomal abnormality is the cause. Chromosomes carry genetic materials. Examples include trisomy 21 or Down syndrome.
A rare type of genetic disorder is the mitochondrial type that results from mutations in the nonchromosomal DNA of mitochondria.