You are unique. No other individual has the identical genetic composition as you. There are similarities between all of us, and we are most similar to our immediate family members. We each inherit half (23) of our chromosomes from our mothers and the other half from our fathers. We are genetically most similar to our siblings, with identical twins being the most similar.
Your genome consists of the DNA (deoxyribonucleic acid) in your 46 chromosomes (see Glossary for definition of terms). This DNA is a double helix of two strands consisting of a sugar-phosphate backbone containing sequential bases of either adenine (A), thymine (T), guanine (G) or cytosine (C). Each individual unit of a DNA strand is referred to as a nucleotide. The nucleotide sequence of one strand determines the sequence of the other strand (the strands are complementary) with A always pairing with T and G always pairing with C, to form A-T and G-C base pairs. The DNA in your genome constitutes a sequence of over 3 billion base pairs. This DNA sequence programs your development from a fetus to an adult, encodes all the proteins produced in your body and controls many other aspects of your appearance and traits.
The genomes of all humans are very similar, in fact about 97-99% identical. However, it is now known that there are 38 million nucleotide positions (single nucleotide polymorphisms, or SNPs) where there are differences between individuals. Each individual has about 3.6 million of these SNPs. The particular nucleotides (or base pairs) at these variable positions are what makes each of us unique.
The DNA sequence variants in your genome contribute to your appearance and other traits, how you respond to environmental influences, your susceptibility to diseases, how you respond to medications and many other characteristics that make you a unique human being. Analysis of your genome can also be used to reconstruct your ancestry. While your genome determines many of your traits, characteristics, susceptibilities and abilities, it does not determine your destiny. Environmental, social and individual factors also have a great influence on our lives. Genetics is one of several very important components that affects each of us.
Over fifty years of research since solving the structure of DNA led to determination of the complete DNA sequence of the human genome, which was formally announced in April, 2003. This resulted in an explosion in our understanding of genetics and genomics, and considerably more will be learned in future years. We are truly living at the time of the genomic revolution. At Genomic Express, we believe your genetic information is your personal property and that you have a right to confidentially obtain and control use of your genetic information. Genomic Express can help you obtain and understand your own genetic information in order to be more informed, take control of your own healthcare and lead a healthier and more productive life.