In every biochemical events in body, there are genes. If human body is a book, genes are just sentences of prose written over it. The entire of genetics complements is called genome. Matt Ridley, a British science editor, in his book Genome (1999) painted that if the genome is a book, there are twenty three chapters, called chromosomes. Each chapter contains stories, called genes. Each stories are made up of paragraphs called exons, which are interrupted by advertisements called introns. Each paragraph is made up of words, called codons. The letters of each word are called basses. Ridley whom wrote his book made up chapters that named after 23 chromosomes, exposed all information about each chromosome based on the number of chapter. In human body, the 23 chromosomes are made up by 22 autosomes and a pair of sex chromosomes (xx in female and xy in male). In size, the 22 pairs are numbered by the largest (number 1) to the smallest (number 22). The sex chromosome X is located between number 7 and number 8, while Y is the smallest.

Genes are located in a chromosome. In each chromosome, there are 400-4000 genes. Genes are written in three bases or called as codon. The 4 bases are Guanine, Cytosine, Adenine, and Thymine. The bases are written on long chains of sugar and phosphate called DNA. During the replication, A likes to pair with T and G likes to pair with C. For instance, the sequence of ACGT becomes TGCA in the copy form. Besides the gene is able to do replication, it is also able doing translation. The translation starts with the transcription of the gene into a copy by RNA with the same base-pairing process except that it uses letter U for uracil to pair with T. Then a ribosome moves along the RNA copy (messenger RNA) translating each codon into twenty different amino acids. Later, the chain of amino acids forms a protein. In conclusion, every protein is a translated gene. Protein itself also responsible to switch gene on or off for being promoter and enhancer of a particular gene.

Unfortunately, during replication mistakes are sometimes made. This is known as mutation. Although genes are small and tiny, this doesn’t mean genes are unimportant. If an error happens in a gene, this may caused flaw in body system. For example, when chromosome 3 is broken it caused a metabolic anomaly disease named alkaptonuria, or like the most famous genetic disease Huntington’s happens because of chromosome 4 mutation and when there is a complete lack in chromosome 4 it may causes rare Wolf-Hirscchorn syndrome, the chromosome 6 if it is broken can cause the problem of human intelligence. In genetic disorder, there is no 50-50 probability you get it or not. You either have mutations, in which case you get these genetic diseases, or you don’t.

But, the genetic doesn’t always work in that digital way. Sometimes, it depends on environment too. Like the case of asthma. There are 15 ‘asthma genes’ in all chromosomes (8 genes in chromosome 5, 2 each in chromosome 6 and 12, and 1 each in chromosome 11, 13, and 14). These genes are producing immunoglobulin E aka IgE. According to medterms.com, IgE acts as antibody in our body by eliciting allergen (allergic mucous). Most asthmatics are allergic to something. Asthma, eczema, allergy, and anaphylaxis are syndrome that triggered by IgE. So, that’s why allergic person has asphyxia.

Asthma itself is a chronic inflammation in bronchial tube and causing the tightening of the windpipe. How does it correlate with chromosome 5? ADRB 2 lies along in chromosome 5 and it responsible to produce beta-2-adrenergic-receptor which controls the bronchodilation and bronchoconstriction that cause the tightening in bronchus or windpipe. According to American Lung Association, feather, pollen, vigorous exercise, dust mites are the most common asthma triggers. No matter what triggers a person to have asthma, his or her asthma syndrome still triggered by IgE.

Sources:
Ridley, Matt. 1999. Genome. USA: Harper Collins.
Medterms.com
Wibowo, Daniel . 2005. Anatomi Tubuh Manusia. Jakarta: Gramedia.

Labels: asthma, biology, chemical, chromosomes, genes, genome