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The following is a list of genetic disorders and if known, type of mutation and for the chromosome involved. Although the parlance "disease-causing gene" is common, it is the occurrence of an abnormality in the parents that causes the impairment to develop within the child.
The smallest single base deletion mutations occur by a single base flipping in the template DNA, followed by template DNA strand slippage, within the DNA polymerase active site. [ 3 ] [ 4 ] [ 5 ] Deletions can be caused by errors in chromosomal crossover during meiosis , which causes several serious genetic diseases .
The three major single-chromosome mutations: deletion (1), duplication (2) and inversion (3). The two major two-chromosome mutations: insertion (1) and translocation (2). When the chromosome's structure is altered, this can take several forms: [16] Deletions: A portion of the chromosome is missing or has been deleted.
Chromosomal deletion syndromes result from deletion of parts of chromosomes. Depending on the location, size, and whom the deletion is inherited from, there are a few known different variations of chromosome deletions. Chromosomal deletion syndromes typically involve larger deletions that are visible using karyotyping techniques.
An example of a disease that is caused by a dominant lethal mutation is Huntington's disease. Null mutations, also known as Amorphic mutations, are a form of loss-of-function mutations that completely prohibit the gene's function. The mutation leads to a complete loss of operation at the phenotypic level, also causing no gene product to be formed.
A contiguous gene syndrome (CGS), also known as a contiguous gene deletion syndrome, is a clinical phenotype caused by a chromosomal abnormality, such as a deletion or duplication that removes several genes lying in close proximity to one another on the chromosome. The combined phenotype of the patient is a combination of what is seen when any ...
Mutations in the β-hexosaminidase A (Hex A) gene are known to affect the onset of Tay-Sachs, with 78 mutations of different types being described, 67 of which are known to cause disease. Most of the mutations observed (65/78) are single base substitutions or SNPs, 11 deletions, 1 large and 10 small, and 2 insertions. 8 of the observed ...
17q12 microdeletion syndrome is an autosomal dominant disorder, where one copy of the relevant mutation is enough to cause the condition. Most cases are de novo, or spontaneous mutations that do not occur in the proband's parents; [10] approximately 75% are de novo, while 25% are inherited. [4]