Human Genetics and Disorders

Since colour blindness is a recessive trait, men, who have only 1 copy of the X chromosome, will always be color blind if they inherit the defective gene. Women must inherit two defective copies in order to be color blind.

Ammonium tetrathiomolybdate [NH₄]₂MoS₄ is bright red ammonium salt, an important reagent in the chemistry of molybdenum and has been used as a building block in bioinorganic chemistry. It was first used therapeutically in the treatment of copper toxicosis in animals. It is also used in the treatment of Wilson's disease.

Endometrial cancer begins in the layer of cells that form the lining (endometrium) of the uterus. The causes of endometrial cancer are still unknown.

Mutations in the BRCA 1 gene (located on chromosome 17) cause most of the ovarian epithelial cancers seen on a hereditary basis.

The c-myc gene (chromosome 8q24) involved in the entry of cells from resting G0 into the cell cycle is translocated to the mu heavy chain gene (chromosome 14q32) in most cases of Burkitt's lymphoma studied.

The common gamma chain is encoded by the gene IL-2 receptor gamma, or IL-2Rγ, which is located on the X-chromosome. For this reason, immunodeficiency caused by mutations in IL-2Rγ is known as X-linked severe combined immunodeficiency. The condition is inherited in an X-linked recessive pattern.

Tum – cell lines are those which have mutated such that they cannot be grown in syngeneic animals with a normal immune system.

Point mutation leads to a single amino acid substitution at either position 12, 13 or 61. These mutations are found in over 90% of patients with pancreatic carcinomas, in 40% of patients with colorectal cancers and their preneoplastic lesions, in acute myeloid leukemia (AML) and in preleukemic syndromes.

Lack of CD154 (CD40L) prevents signalling to the B-cell CD40 to bring about Ig class-switching away from IgM.

Replacement immunoglobulin therapy is also used in CD40 ligand deficiency. Ig is prepared from the plasma collected from a large number of normal individuals, usually between 10,000-50,000, who have been carefully screened to make sure they are healthy and do not harbor certain infectious diseases. The plasma contains a broad range of specific antibodies to many different types of bacteria and viruses.

The BRCA2 mutation is the most likely to be associated with male breast cancer.

Cancer is regarded as a genetic disease because it is caused by mutations in the genome. However, these mutations are normally in somatic cells not germ cells and mutations contributing to cancer are rarely inherited. To form a malignant cancer a cell must acquire a small number of mutations (probably about six) each of which gives the cell a growth or survival advantage.

Fas forms the death-inducing signaling complex (DISC) upon ligand binding. Membrane-anchored Fas ligand trimer on the surface of an adjacent cell causes oligomerization of Fas.

EGFR is a cell surface protein that binds to epidermal growth factor. Binding of the protein to a ligand induces receptor dimerization and tyrosine autophosphorylation and leads to cell proliferation. Mutations in this gene are associated with lung cancer. Multiple alternatively spliced transcript variants that encode different protein isoforms have been found for this gene.

Determination of HLA haplotype is based on association of particular haplotype with risk of disease, particularly autoimmune disease. It does not diagnose disease, and finding at-risk haplotype does not guarantee that disease will eventually occur. Rather, it identifies individuals who are predisposed to disease.