Essay !9 - Relavance of Somatic Aneuploidy to Human physiology and Health Code : KSI0009

Genomics Essay # 9

UNIST BIO Junior 20141110 Sangin Kim

2016.11.09. (Wed)

Relevance of Somatic Aneuploidy to Human Physiology and Health

 

I want to write about the somatic aneuploidy and it’s relavance on human physiology and health. Chromosomal aneuploidy is the phenomena that the homologous chromosome’s number is different. We are knowing that the chromosomal instability including gene disruption can occur by translocation, deletion, insertion and inversion. For example, in case of the mutation which cause the frameshift mutation(3n+1 or 3n+2), the premature stop codon would arise and further, NMD(nonsense mediated decay) would occur then the gene would have the null function. This kind of gene dysfunction would related to the severe phenotype. However, in case of chromosomal change, it’s more severe problem than only the change of the gene. The reason is that lots of genes are linked to the chromosome. In other words, the chromosome is the combination and set of the genes. From now on, we will talk about the somatic aneuploidy. Further, I want to deal about this kind of somatic aneuploidy and the relationship between the somatic aneuploidy and the human physiology and health in vivo.

 

The aneuploidy of somatic cell means that abnormal number of chromosomes are in one cell. In case of human(homo sapiens), there are total 46 chromosome are exist, and among them. 44 chromosomes are autosome and 2 chromosomes are sex chromosomes. We would deal the autosome. In other words, autosome could be 43 or 45 not 44. The taxonomy of chromosome aneuploidy are same as follows. Monosomy, disomy, trisomy, tetrasomy, pentasomy and so on and this means the number of copies of chromosomes.

Then, why this aneuploidy occurs? The most important reason would the nondisjunction of chromosome. Our cells are including the chromosome and it continues and repeats the replication and disjunction. If nondisjunction occur during the cell cycle which is consisted with many sequential phase, the aneuploidy can made. and it could result the abnormal zygotes which has abnormal number.

 

If these kind of chromosome aneuploidy occurs, lots of severe phenotype would occur. From now on, we want to talk about the autosome aneulploidy and the relationship with human physiology and health. At first, monosomy and the deletion. The most popular example is the chromosome 5q deletion syndrome. This syndrome’s phenotype is the children crying sound is like the cat’s crying sound. Also, the chromosome 22 of 22q11.2 deletion would result the Digeorge syndrome and it’s also the typical example of the autosome deletion. Then, let’s talk about the autosome aneuploidy in more detail. Perhaps, we all know the ‘Down syndrome which is trisomy 21’. Except this syndrome. Edwards syndrome, Trisomy 18, Patau syndrome, trisomy 13 or trisomy D are exist. These syndromes are only the part of aneuploidy and unknown syndrome could be more than the known syndrome I think. Noticeably this chromosomal instability and aneuploidy are known that they are linked to the sarcoma, lymphoma, and leukemia like tumorigenesis.

 

Likewise, the aneuploidy and nondisjunction are affecting severely to human. Even though the frequencies are lower than the other disease, we should closely research about this phenomena. Of course, only some cells aneuploidy would not affect to the human and they would degraded by apoptosis. However, if that kind of cells are accumulated, they would form the mosaic in human body and it would cause the chromosomal instability. Finally it could result the leukemia or lymphoma like tumorigenesis. So I think we should research not only in vitro, but also in vivo with regard to the chromosome instability, nondisjunction and anupoloidy.