Chromosome+9

=__**CHROMOSOME 9 **__= = =

Size of Chromosome:
Chromosome 9 is made up of about 140 million DNA base pairs long, and represents approximately 4.5% of the total DNA in cells. It most likely contains 800 and 1,300 genes. These genes are about 20,000 to 25,000 total genes in the human genome. ([|Chromosome 9])

=**__EXCERPT FROM GENOME __**= =** "Blood grouping presumes innocence. That is to say, a negative result can prove you were not the murderer absolutely, but a positive one can only suggest that you might be the murderer." **= =** (Ridley, M., 1997) **= = = = GENE 1- ABCA-1 =

ABCA-1: //ATP-binding cassette, sub-family A (ABC1), Member 1//
The ABCA1 gene belongs to a group of genes called the ATP-binding cassette family, that provides instructions for making the proteins that transport molecules across cell membranes. The protein for ABCA1 is made in tissues, particulary in the liver and in immune system cells (macrophages).

This protein is used to move cholesterol and fats called phospholipids across the cell membrane to the outside of the cell. Then the substances are picked up by the protein alopoprotein (apoA1) that circulates inside the bloodstream. ApoA1 is used for making HDL, which is known as the "good cholesterol" because high levels of this substance reduce chances of developing heart and cardiovascular disease. HDL will carry cholesterol and phospholipids from the body's tissues to the liver, and there they are removed from the blood.

The Location of ABCA1: Cytogenetic Location: 9q31.1 Molecular Location on chromosome 9: base pairs 107, 543, 282 to 107, 690, and 526.

([|ABCA1]) = GENE 2- HSD17B3 =

HSD17B3: //hydroxysteroid (17-beta) dehydrogenase 3//
HSD17B3 provies instructions for making an enzyme called 17-beta hydroxysteroid dehydrogenase 3. This enzyme is active in the male testes where it helps to produce the male sex hormone testosterone for a precursor hormone, called androstenedione.

17-beta hydroxysteroid dehydogenase 3 deficiency is caused by mutations in the HSD17B3 gene. More than 20 mutations that can cause this deficiency are already identified in the HSD17B3 gene. This condition is most common in the Arab population of Gaza. Almost all affected individuals have two copies of the same mutation. It replaces the amino acid arginine with the amino acid glutamine at protein position 80.

Mutations in HSD17B3 result in a 17-beta hyroxysteroid dehydrogenase 3 enzyme with little or no activity. This reduces testosterone production. A shortage of testosterone affects the development of the reproductive tract in the male fetus, which will result in the abnormalities in the external sex organs that occur in 17-beta hydroxysteroid dehydrogenase 3 deficiency.

Location of HSD17B3: Cytogenetic Location: 9q22 Molecular Location on chromosome 9: base pairs 98,997,588 to 99,064,433.

([|HSD17B3]) =__DISORDER __=

Kleefstra Syndrome
Kleefstra syndrome is a disorder that, if obtain, affects many parts of the body. Features include developmental delay and intellectual disability, severely limited or absent speech, and weak muscle tone. Individuals with Kleefstra syndrome usually have a smaller sized head and a wide, yet short, skull.

In the faces of the affected individuals, the eyebrows grow together in the middle, and the eyes are widely spaced apart. The middle area of the face is sunken, and nostrils open towards the front, instead of downward. Finally, a protruding jaw, rolled outward lips, and a large tongue are the other facial features.

Those who suffer from Kleefstra syndrome may have an abnormally high birth weight, and may deal with obesity as a child.

They may also have to endure structural brain abnormalities, utter heart defects, genitourinary abnormalities, seizures, and a tendency to develop severe respiratory infections. While in their childhood, they may encounter features of autism or related developmental disordors that will have an impression on one's communication and interaction socially. As an adolescent, the development of loss of interest and enthusiasm, or unresponsiveness, may occur.

Kleefstra syndrome is caused by the loss of EHMT1 gene, or by mutations that will disable the function of this gene. EHMT1 gives instructions for making the enzyme euchromatic histone methltransferase 1. Majority of people who have Kleefstra syndrome are missing a sequence of about one million base pairs on one copy of chromosome 9 in each cell.

However, only about a quarter percent of those tested with Kleefstra syndrome do not have a deletion of genetic material of chromosome 9. Instead they have mutations in EHMT1.

([|Kleefstra Syndrome])

=__ INTERESTING FACTS __=
 * The genes in this chromosome are about 20,000 to 25,000 total genes in the human genome.
 * "Deletions of part or all of chromosome 9 are commonly found in bladder cancers."
 * Changes to chromosome 9 include an extra piece of the chromosome in each cell, a missing segment of the chromosome in each cell, and a circular structure called a ring chromosome 0.

= = 1) chromosome 9 - Google Search. (n.d.). //Google//. Retrieved May 8, 2012, from []

2) Chromosome 9 - Genetics Home Reference. (n.d.). //Genetics Home Reference - Your guide to understanding genetic conditions//. Retrieved May 8, 2012, from []

3)Kleefstra Syndrome - GGCWiki. (n.d.). //GGCWiki//. Retrieved May 9, 2012, from [] 4)

ABCA1 - ATP-binding cassette, sub-family A (ABC1), member 1 - Genetics Home Reference. (n.d.). //Genetics Home Reference - Your guide to understanding genetic conditions//. Retrieved May 11, 2012, from []

5) HSD17B3 - hydroxysteroid (17-beta) dehydrogenase 3 - Genetics Home Reference. (n.d.). //Genetics Home Reference - Your guide to understanding genetic conditions//. Retrieved May 11, 2012, from http://ghr.nlm.nih.gov/gene/HSD17B3