Types and List of Examples of Genetic (Hereditary) Diseases

There are 4 types of genetic diseases.

A genetic disease or disorder is any disease caused by a problem with a person’s genes. A person’s genes are contained within their genome. The human genome is made up of the 46 human chromosomes (22 pairs of autosomal chromosomes and 2 sex chromosomes). These 46 chromosomes together contain over 3 billion base pairs of DNA that contain about 20,500 protein-coding genes. The actual protein-coding genes account for less than 5% of the human genome. The precise function of the 95% of remaining DNA is unclear. Some researchers include mitochondrial DNA as part of the human genome.

There are about 6000 known genetic disorders; many are fatal or cause severe problems while others may not but may add to problems that are triggered by non-genetic (for example, environmental conditions).

Genetic disorders can range from a defect in a single base mutation in the DNA of one gene to chromosomal abnormalities that involve deletion or addition of entire chromosomes or sets of chromosomes. Genetic disorders can be inherited, or passed from parents to offspring, or acquired due to changes in an individual’s DNA that occur during their lifetime. Radiation and certain cancer-causing chemicals are examples of causes of acquired changes to DNA. This short article is designed to give the reader a list of groups of diseases that share genetic problems that are similar in cause. The lists have examples of genetic disease types and are not all inclusive.

There are many types of genetic diseases. Four of the main types are:

1. Single-gene inheritance diseases
2. Multifactorial genetic inheritance disorders
3. Chromosome abnormalities
4. Mitochondrial genetic inheritance disorders

Single gene inheritance diseases are diseases that occur because one defective gene is present. They are known as monogenetic disorders. There are thousands of known single gene inheritance diseases, and they may be inherited in different ways. Autosomal dominant inheritance means that only one copy of the defective gene (from either parent) must be present to cause the condition. Autosomal recessive diseases require that an affected person receive a defective copy of the gene from each parent. X-linked disorders refer to diseases for which the defective gene is present on the female (X) chromosome.

Examples of single gene inheritance disorders include:

1. Cystic fibrosis
2. Sickle-cell anemia
3. Marfan syndrome
4. Duchenne muscular dystrophy
5. Huntington disease
6. Polycystic kidney disease types 1 and 2
7. Tay-Sachs disease
8. Phenylketonuria
9. Maple syrup urine disease
10. Neurofibromatosis type 1
11. Alpha-1 antitrypsin deficiency
12. Galactosemia
13. Familial hypercholesterolemia
14. Rett syndrome
15. Hemophilia
16. Fanconi anemia
17. Kartagener syndrome
18. Xeroderma pigmentosum
19. Hereditary spherocytosis
20. Tuberous sclerosis
21. Von Hippel-Lindau syndrome

A genetic disease or disorder is any disease caused by a problem with a person’s genes. A person’s genes are contained within their genome. The human genome is made up of the 46 human chromosomes (22 pairs of autosomal chromosomes and 2 sex chromosomes). These 46 chromosomes together contain over 3 billion base pairs of DNA that contain about 20,500 protein-coding genes. The actual protein-coding genes account for less than 5% of the human genome. The precise function of the 95% of remaining DNA is unclear. Some researchers include mitochondrial DNA as part of the human genome.

There are about 6000 known genetic disorders; many are fatal or cause severe problems while others may not but may add to problems that are triggered by non-genetic (for example, environmental conditions).

Genetic disorders can range from a defect in a single base mutation in the DNA of one gene to chromosomal abnormalities that involve deletion or addition of entire chromosomes or sets of chromosomes. Genetic disorders can be inherited, or passed from parents to offspring, or acquired due to changes in an individual’s DNA that occur during their lifetime. Radiation and certain cancer-causing chemicals are examples of causes of acquired changes to DNA. This short article is designed to give the reader a list of groups of diseases that share genetic problems that are similar in cause. The lists have examples of genetic disease types and are not all inclusive.

Chromosome abnormalities usually result from a problem with cell division and arise because of duplications or absences of entire chromosomes or pieces of chromosomes. Examples of chromosome abnormality disorders include:

1. Down syndrome
2. Cri-du-chat syndrome
3. Klinefelter syndrome
4. Patau syndrome (trisomy 13)
5. Edwards syndrome (trisomy 18)
6. Turner syndrome
7. 22q11.2 deletion syndrome
8. Ring chromosome 14 syndrome
9. Prader-Willi syndrome

Mitochondrial genetic inheritance disorders are caused by mutations in the DNA of mitochondria, small particles within cells. This DNA is unique in that it is not located on the chromosomes in the cell nucleus. Mitochondrial DNA is always inherited from the female parent since egg cells (unlike sperm cells) keep their mitochondrial DNA during the process of fertilization. Examples of mitochondrial genetic inheritance disorders include:

1. Hereditary optic atrophy
2. Barth syndrome
3. Co-enzyme Q10 deficiency
4. Myoclonic epilepsy with ragged red fibers (MERRF)
5. MELAS syndrome, a rare form of dementia
6. Kearns-Sayre syndrome
7. Pearson syndrome
8. Neuropathy, ataxia, retinitis pigmentosa (NARP)
9. Leigh’s disease