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DNA sequence
An error in the
Genetic Sequence
is known as:
Chromosome
Mutation
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Chromosome Aberrations are: dysfunction or alterations in the number of chromosomes or in the form and structure thereof. Basically these anomalies are due to problems during gametogenesis (structuring or training through meiosis of gametes) or the first subdivisions or divisions of the zygote.
These dysfunctions or alterations can be observed at metaphase during the cell cycle, which originate from the very moment of the general division, because during the natural and normal process of division is an error or abnormal division, named (process clastogenic) , which is nothing but a faulty division, giving rise to the famous genetic mutations in the DNA chain.
Chromosome aberration called "Numerical Abnormality"
The chromosome number abnormality is an alteration in the number of duplicates or copies of any non-sex chromosomes. Some alterations in the number of chromosomes usually produce alterations in the human phenotype, these changes occur as well-known genetic disorders, Down syndrome, Edwards syndrome, Patau syndrome, among others.
Anomalies or numerical aberrations of sex chromosomes
The alteration in the number of duplicates or copies of any of the sex chromosomes is known as human numerical sex chromosome abnormality among the best known of these genetic alterations are: Klinefelter syndrome, Turner syndrome, Twin Syndrome And, the Triple X Syndrome, among others.
Numerical abnormalities not, better known as anomalies or structural aberrations
Aberrations or structural anomalies are not numeric arising from changing the order of the normal programmed genetic strands that are part of a chromosome. These anomalies or chromosomal aberrations arise as a consequence of chromosomal breaks or cuts, followed immediately by abnormal connections or incomplete reconstructions or too much that is anomalous and not according to genetically programmed sequence. In general average such anomalies are less frequent than aneuploidy abnormalities, and according to statistics 1 in 375 live births suffer from this genetic disorder and thus have a possibility of a 0.0027% of autism.
Structural anomalies or structural abnormalities can also occur non-numeric as a result of external factors such as radiation, chemicals and viruses in all its forms and is called external factors such clastogenic, yet also can produce this type of anomaly or genetic aberrations spontaneously form or which are even more rare and scarce. As for the spread of the anomaly or aberration genomics and organs affected as a result of these do not make the same distinction, ie both numerical aberrations or abnormalities as well as organizational dissemination may be complete or skipped over all body cells affected, which is believed that it is purely chromosomal order of birth from the moment of conception the zygote state and even in its early stages of cell division.
Other types of aberrations or structural abnormalities (mutations) are caused by transposons initially mentioned and described by Barbara McClintock, who are nothing more than jumping genes or mobile, ie they are able to modify their position in the human genome, jumping from one chromosome to another chromosome, thus causing alterations in the gene sequence, which is called a genetic mutation or structural order.
Currently there are two different types of anomalies or genetic aberrations cutting structural aberrations or structural anomalies and aberrations balanced or unbalanced structural abnormalities.
Balanced structural abnormality or aberration
The key feature of this mutation is that the amount of genetic material is the same ie only changes its form or structure, plus the same neither increases nor decreases.
Unbalanced structural anomaly or aberration
Unlike the balanced structural abnormality or aberration, in this type of mutation if the increase or decrease the amount of genetic material.
In both cases it may be mitotic and meiotic divisions, without altering the amount of genetic material, however in some cases there may be more than 1 over 2 centromere and telomeres would be normal.
Structural abnormalities or aberrations Sex
Is called with this name to genetic mutations that alter the order or internal organization of the sex chromosomes. An example of this type of genetic abnormality X syndrome is very common in this type of genetic disorder, which presents a very peculiar and characteristic symptoms.
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