Chromosome 9
Type:: Genetic
Gorlin syndrome (also known as basal cell nevoid carcinoma syndrome) is caused by microsuppression 9q22.3 is a chromosomal change in which a small part of the long arm (q) of chromosome 9 is removed in each cell. Affected people are missing at least 352,000 base pairs, also written as 352 kilobases (kb), in the q22.3 region of chromosome 9. It is one of the smallest suppressions detected that can cause disorders, which can occur as developmental delay, intellectual disability, certain physical abnormalities and characteristic features. The 9q22.3 microdeletions can also be much larger; the largest reported elimination included 20.5 million base pairs (20.5 Mb). People with a 9q22.3 microdeletion lack two to more than 270 genes on chromosome 9. All known 9q22.3 microdeletions include the PTCH1 gene, which is believed to be responsible for the disorders.
Bladder Cancer is associated with deletions of chromosome 9 genes, these genes are believed to prevent bladder cells from reproducing uncontrollably. Currently the studies are focused on determining what these genes are and their specific functions.
Chronic myeloid leukemia is due to a reorganization (translocation) of genetic material between chromosomes 9 and 22; It is a type of cancer of the blood cells. This slow-growing cancer leads to an overproduction of abnormal white blood cells. Common characteristics of the condition include excessive tiredness (fatigue), fever, weight loss and enlargement of the spleen. The translocation involved in this condition, written as t (9; 22), fuses part of the ABL1 gene on chromosome 9 with part of the BCR gene on chromosome 22, creating an abnormal fusion gene called BCR-ABL1. The abnormal chromosome 22, which contains a part of chromosome 9 and the fusion gene, is commonly called the Philadelphia chromosome. Translocation is acquired during the life of the person and is present only in abnormal blood cells. This type of genetic change, called somatic mutation, is not inherited.
Kleefstra syndrome, is a disorder that affects many parts of the body. A sequence of approximately 1 million DNA building blocks (base pairs) may be missing in a copy of chromosome 9 in each cell. Elimination occurs near the end of the long arm (q) of the chromosome at a location designated q34.3, a region that contains a gene called EHMT1. Some affected people have shorter or longer deletions in the same region. The EHMT1 gene provides instructions for making an enzyme called euchromatic histone methyltransferase 1. The lack of this enzyme impairs proper control of the activity of certain genes in many of the body's organs and tissues, resulting in characteristic developmental and function abnormalities. of Kleefstra syndrome.
Other types of cancer Changes in the structure of chromosome 9 have been found in many types of cancer. These changes, which occur only in the cells that give rise to cancer, generally involve a loss of part of the chromosome or a reorganization of the chromosomal material. For example, a loss of part of the long arm (q) of chromosome 9 has been identified in some types of brain tumor. In addition, chromosomal rearrangements have been found that fuse the ABL1 gene with genes other than BCR in a small number of acute leukemias.
Other anomalies Several anomalies have been found on chromosome 9 such as translocations, deletions, duplications or rings that cause disorders of various kinds.
