The genome is the most complicated and intricate entity ever discovered. Billions of building blocks come to together in perfect harmony to encode for life. The complexity and extreme specificity of coding produced in the DNA of every living organism, and within every living cell, is comprised of only four nucleotides. It is amazing to ponder the idea that all of life can be explained by the assortment and rearrangement of just four simple building blocks, Adenine, Thymine, Guanine, and Cytosine. In a healthy and stereotypical organism, the organization of these nucleotides is carried out flawlessly in almost every cell throughout the body, each containing the same set of perfectly ordered pairs. Although the human genome is nearly perfect in its attempt to copy and organize its DNA to allow man to thrive, a small minority of people are unfortunate enough to endure the wrath of this near perfection.
So what happens when the human genome endures a problem in its coding of nucleotides? Often, a mistake in the DNA coding goes unnoticed, meaning the mutation in the ordering of nucleotides does not affect the organism as a whole. However, when the mutation is significant, dramatic changes in the organism are evident, and often devastating. There are countless diseases that are caused by a simple miscoding among nucleotides, which impair the person and negatively affect their development and ability to function. In order to better understand and perhaps find a cure for these genetic based diseases, science must first grasp and interpret the malfunction occurring on the DNA level. Although these diseases have permeated mankind for thousands of years, the strides in genomic based science has allowed an imperceptible growth of understanding. These diseases, such as autism, are an urgency that must be better understood in order for man to escape the tragic and devastating blight that they inflict.
In a recent study conducted by Dr. Simon Gregory published in the BioMed Central Journal, the mystery of the genetic causes of autism were discussed. The experiment and subsequent analysis of possible genetic malfunctions related to autism proposes a correlation between a deficiency in the oxytocin receptor in the human body. The method in which the experiment was conducted was that a high-resolution genome-wide microarray and comparative genomic hybridization identified variants within 119 probands from families with multiple cases of autism. Next, the experiment continued by undertaking DNA mythylation analysis of peripheral blood and temporal cortex DNA of autism cases and compared that with a control group. One aspect in identifying the mechanism that causes autism is the genes that characterize copy number variants, or CVNs. The most important and significant aspect of the experiment discussed is that the deletion of the oxytocin receptor gene, OXTR. These findings were further explored by observing the correlation between OXTR and autism by using epigenetic analysis of the promoter region of this. Although autism is a complex and intricate disease, just like any genetic disorder, the misregulation of OXTR is the main focus of the experiment in an attempt to explain the disorder.
In the experiment it was determined that the CVNs were extremely significant in a correlation with autism in patients. In the 119 autism probands a total of 113 within 111 autistic individuals exhibited one or more deletions or duplications, ranging from one to six CNVs per individual. Previously, only one of the genes in question were associated with autism, yet the experiment reveals that there are far more than that. Now not only is a deletion on the chromosome 8q22.2 associated with this disorder, but also deletion of sections within the chromosomes 2q24.1-2q24.3, 15q11-13, and 3p25.
Similarly, the deletion of OXTR could result in a reduction in levels of OXTR available during the development of a child in utero, which may lead to the development of autism. Although this is a possibility, it does not account for the fact that one child in a family with this deletion of OXTR may have autism, but a child in the same family with the same deletion does not have autism. Thus, this study reveals that there must be another mechanism that has a profound influence on autism. In conjunction with this idea, it is determined that the increase in DNA methylation leads to gene silencing, which can be a factor in autism. An increase in DNA methylation of found within a critical region of OXTR regulation may be a more important factor and could represent a more generalized reason for autism. For example, in the study a group of autistic males with an increase in methylation in the .934 site exhibited 20% less expression. Thus, OXTR has a significant correlation with decreased expression of the gene associated with autism.
The article was significantly more difficult to read than any other article thus far. It was difficult to infer the meaning of the information because most of the terms were not familiar, and the context clues surrounding them were just as or more difficult. However, the ideas behind the words were relatively easy to understand. The implications of understanding the mechanisms behind a serious disease like autism has profound real world applications. Although this is just one of many studies that must be done to understand the reason for autism on a genetic level, it is a small preview of what is to come. It may seem like an impossibility for autism to be cured, but once it is fully understood and personalized genomes are economically sensible, it is a distinct possibility that autism, and related diseases, may be a worry of the past. This is an urgency of the twenty-first century, yet with sufficient research and experimentation science will discover a solution.
Gregory, Simon. "Genomic and epigenetic evidence for oxytocin receptor deficiency in autism." BioMed Journal (2009): n. pag. Web. 15 Nov 2009.