DON'T MAKE A MESS, IT WILL COST YOU!
Let's dedicate this post to explaining the 13 common types of genetic mutations I noted in part II of this series of posts about genetic mutations. Obviously, one post cannot include all the information relevant to every mutation, yet I will explain and indicate the main pointers regarding each genetic mutation type.
Deletion genetic mutations:
Deletion mutations occur when a part of a chromosome or DNA is not included during the DNA replication process. The extent of genetic matter that is "left out" of the process can span one nucleotide to large sequences of DNA. The greater the sequence deleted, the greater the chances that the sequence will include functional DNA of importance. Several deletion mutations have been identified as the cause of congenital anomalies or birth defects and significant intellectual and physical disability.
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Insertion genetic mutations:
Insertion mutations occur when one or more nucleotides are added to the genetic code making it longer. This can cause anything from a shift in the reading frame to the addition of endless (in theory) of codons to the sequence, changing the outcome completely. It can cause vast sections of the code to mean nothing or mean something completely different: a whole different protein produced, an inactive protein, or a deformed protein, a defective protein, or a protein allowing us to gain an unbelievable advantage.
Missense genetic mutations:
Missense mutations occur when a single nucleotide is replaced by another (wrong) nucleotide, causing a completely different amino acid to be included in the polypeptide (protein) to be created (synthesized). This is considered a "point mutation" since there is a single nucleotide pair (base pair) being deleted, added, or changed. One incorrect amino acid is enough to deem a protein ineffective, inactive, defective, dysfunctional. A defective protein can cause critical damage to an entire process, life and death damage even, depending on how central the protein is to a major process, and the process' importance' magnitude.
Frameshift genetic mutations:
Our genetics is has a major disadvantage and weak spot. It is extremely sensitive to the codons being a specific sequences of three nucleotides. It is enough that each nucleotide (the equivalent of a letter in a word or sentence) is changed, and the whole meaning could change. If a nucleotide is deleted (taken out) the genetic reading frame may change. For example, one of the codons coding for the amino acid arginine is CGG, if the cytosine nucleotide (C) is deleted (taken out) the genetic sequence is shortened causing the sequences to be read as GGG, which will result in the creation of the amino acid Glycine instead. This change will effect the reading of the entire sequence in a similar way.
Another example for a frameshift genetic mutation would be the addition of a nucleotide, causing a similar effect (in essence) to the genetic reading frame of the genetic sequence. For example, the codon UGU codes for the amino acid cysteine, if a cytosine nucleotide is added (inserted into) the genetic sequence after the guanine and before the last uracil, the codon become UGG, which codes for the amino acid tryptophan instead.
Similar effects to the genetic reading frame can be caused by the deletion of more than one nucleotide, or the addition of more than one nucleotide. Thus, frameshift genetic mutations are the result of a deletion of a single nucleotide or multiple nucleotides and/or the addition/insertion of a single nucleotide or multiple nucleotides, into the genetic code (DNA sequence). In other words, a frameshift mutation is the result of one or more deletion, insertion, or missense mutations.
Gene duplication genetic mutations:
Is the result of molecular evolution where a whole region of DNA that contains a gene is duplicated.the sequence duplicated can be duplicated once or more, being added and inserted into the genetic code, causing it to elongate. These mutations give rise in evolution to new genes and functions (bad or good). It is the basis for evolution in general and the ability of a species to adapt to changing conditions and environments.
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I have included 5 out of the 13 common mutation types in this post, more to follow in the next posts of this series of posts dedicated to genetic mutations. Stay tuned, subscribe on the website for FREE, follow on twitter, or subscribe to my YouTube channel. KIIP by Dr. Saghiv.
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