The genome of a single person. Part 1

Today we are going to talk on the application of the genome. In this case would be the genome and myself, my own genome or the genome of a single person, in which we are going to talk on this view of personal genomics, then a description of the information of my genome and to have an overview of the challenges of this kind of analysis. Personal genomics is a branch of genomics concerned with the sequencing analysis and mainly the interpretation of the genome of an individual, a single genome.

The description may be done in several ways the most standard nowadays is to do a SNP typing in which tens of thousands or even millions of SNPs are type in a genome and then we have to do the interpretation, the meaning of this variant. There are two main brands of this kind of SNP analysis and we could also do the whole genome sequencing for which there are lots of technologies mainly driven by Illumina. In all the cases, we do the description but then we may ask for what we want this information and what can we read from that.

The most important thing is that the link between the genotype and the phenotype is not always easy because at the very end we could ask what makes me mean or what can we read in the genome that makes my own individuality. As you are going to see, we have only partial information, very partial information on that. First, we have to do this kind of analysis and this may be done at home so there are lots of companies –in this webpage you can see several companies that to that– and with this information we can go through the typing and then interpretation. My own genome. In my case, the first interesting characteristic we see in my genome is that I’m colour-blind.

Colour-blind is a characteristic that it’s quite frequent, it’s among 7% of males, it’s in the X chromosome, and in many other languages we complain that the word for the name ‘colour-blind’ is not proper in the sense that we do see colours, and John Dalton as the person that described that first, in many languages to be colour-blind is called to be daltonian or daltonist meaning that we see the colours in a different way. For example, in this chart I don’t see anything at all –I guess you see one of the pictures you have down. And here you have several numbers of which you can see inside these points.

I don’t see anything at all, so these are specifically for a kind of colour-blindness and we can see how this is transmitted. This is transmitted in the X chromosome meaning that my mother was carrier of this characteristic and a woman carrier will have one-half of the sons with colour-blindness and one-half not colour-blind –I’m not going to say normal. For woman it’s very difficult to be colour-blind because she should have the father [colour-blind] and the mother carrier, so it’s extremely rare. In my case, here you have my own genealogy and I am the person with the arrow, so I have a cousin that also has the characteristic.

The interesting point here is that we have two genes, and two genes, this gene codes for a protein called opsin in which they have different wavelengths, different colours in which they have the peak of absorbance meaning that green and red are very close in the spectrum of lights, but we have two different opsins for that. Colour-blinds –like myself– what we have is just a single one because in the X chromosome what we have sometimes is non-homologous

recombination meaning that recombination happens between two different genes that are very similar: the opsin for green, the opsin for red. And then we get a hybrid gene in which instead of having two, one for red and or green, we have a single one meaning that we see the colours, but we cannot make a sharp distinction between red and green as other people do.