Some genetic disorders are cystic fibrosis, sickle cell anemia and Down syndrome, reports MedicineNet. There are four main types of genetic diseases, one of which is mitochondrial inheritance. The other three are single gene inheritance, multifactorial inheritance and chromosome abnormalities.
Single-gene disorders occur in the DNA sequence of only one gene, states MedicineNet. There are several thousand genetic disorders of this kind. Other diseases in this category include Huntington's disease and hemochromatosis.
Cystic fibrosis occurs due to a mutation on the CF gene on chromosome 7, according to MedicineNet. People with cystic fibrosis produce a large amount of mucus that blocks the lung passages and can lead to infections. Abnormally shaped red blood cells that affect blood flow and oxygen levels is a characteristic of sickle-cell anemia, notes Mayo Clinic.
Multifactorial disorders affect several genes and are often the result of a combination of environmental and genetic factors, explains MedicineNet. Examples of these disorders are Alzheimer's and diabetes. An abnormality in the amount of chromosomes causes chromosomal disorders such as Down syndrome. This disease is present when a person has three copies of chromosome 21. Mutations in the mitochondria also lead to a group of genetic disorders known as mitochondrial inheritance. Examples of this type of disorder are Leber's hereditary optic atrophy and a form of mental illness called MELAS.