Single Gene Disorder
| Disorder prevalence (approximate) | |
|---|---|
| Autosomal dominant | |
| Familial hypercholesterolemia | 1 in 500 |
| Polycystic kidney disease | 1 in 1250 |
| Neurofibromatosis type I | 1 in 2,500 |
| Hereditary spherocytosis | 1 in 5,000 |
| Marfan syndrome | 1 in 4,000 |
| Huntington's disease | 1 in 15,000 |
| Autosomal recessive | |
| Sickle cell anemia | 1 in 625 |
| Cystic fibrosis | 1 in 2,000 |
| Tay-Sachs disease | 1 in 3,000 |
| Phenylketonuria | 1 in 12,000 |
| Mucopolysaccharidoses | 1 in 25,000 |
| Lysosomal acid lipase deficiency | 1 in 40,000 |
| Glycogen storage diseases | 1 in 50,000 |
| Galactosemia | 1 in 57,000 |
| X-linked | |
| Duchenne muscular dystrophy | 1 in 7,000 |
| Hemophilia | 1 in 10,000 |
| Values are for liveborn infants | |
A single gene disorder is the result of a single mutated gene. Over 4000 human diseases are caused by single gene defects. Single gene disorders can be passed on to subsequent generations in several ways. Genomic imprinting and uniparental disomy, however, may affect inheritance patterns. The divisions between recessive and dominant types are not "hard and fast", although the divisions between autosomal and X-linked types are (since the latter types are distinguished purely based on the chromosomal location of the gene). For example, achondroplasia is typically considered a dominant disorder, but children with two genes for achondroplasia have a severe skeletal disorder of which achondroplasics could be viewed as carriers. Sickle-cell anemia is also considered a recessive condition, but heterozygous carriers have increased resistance to malaria in early childhood, which could be described as a related dominant condition. When a couple where one partner or both are sufferers or carriers of a single gene disorder and wish to have a child, they can do so through in vitro fertilization, which means they can then have a preimplantation genetic diagnosis to check whether the embryo has the genetic disorder.
Read more about this topic: Genetic Disorder
Famous quotes containing the words single and/or disorder:
“Through dinner she felt a gradual icy coldness stealing through her like novocaine. She had made up her mind. It seemed as if she had set the photograph of herself in her own place, forever frozen into a single gesture.”
—John Dos Passos (1896–1970)
“Without metaphor the handling of general concepts such as culture and civilization becomes impossible, and that of disease and disorder is the obvious one for the case in point. Is not crisis itself a concept we owe to Hippocrates? In the social and cultural domain no metaphor is more apt than the pathological one.”
—Johan Huizinga (1872–1945)