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
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