sábado, 16 de febrero de 2019

What is Chromosome 3?

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By Ananya Mandal, MDReviewed by Sally Robertson, B.Sc.

Chromosome 3 is the third largest of the 23 pairs of chromosomes found in humans. It spans nearly 200 million base pairs, the building blocks of DNA, making up around 6.5% to 7% of the genetic material in the human genome.

Image Credit: NIH

Structure and functions of chromosome 3

Chromosome 3 is metacentric, meaning its centromere is positioned somewhere around its centre. There are several vital and important genes located on this chromosome including certain gene clusters that code for the olfactory receptors (involved in sense of smell) as well as chemokine receptors that aid inflammatory processes. Genetic research is focused on identifying the genes on our chromosomes and estimates suggest that chromosome 3 contains around 1100 to 1500 genes.

Some of the important genes that are present on chromosome 3 include:

On the short or "p" arm of the chromosome

ALAS1 - codes for aminolevulinate, delta-, synthase 1 enzyme)
BTD - (codes for biotinidase enzyme)
CCR5 - codes for chemokine C-C motif receptor 5
CNTN4 - codes for Contactin 4
COL7A1 - codes for collagen type VII, alpha 1
MITF - mutations result in microphthalmia-associated transcription factor
MLH1 - mutatinos lead to colon cancer, nonpolyposis type 2
PTHR1 - codes for parathyroid hormone receptor 1
SCN5A - codes for voltage-gated, type , alpha sodium channel and mutation leads to Long QT syndrome 3
SLC25A20 - codes for carnitine/acylcarnitine translocase
TMIE - codes for transmembrane inner ear
VHL - codes for von Hippel-Lindau tumor suppressor