Robertsonian translocationRobertsonian translocation (ROB) is a chromosomal abnormality wherein the entire long arms of two of a certain type of a chromosome called an acrocentric chromosome become fused to each other. It is the most common form of chromosomal translocation in humans, affecting 1 out of every 1,000 babies born. It does not usually cause direct health difficulties, however such persons are almost always infertile because their chromosome count does not match that of most humans.
Cri du chat syndromeCri du chat syndrome is a rare genetic disorder due to a partial chromosome deletion on chromosome 5. Its name is a French term ("cat-cry" or "call of the cat") referring to the characteristic cat-like cry of affected children (sound sample ). It was first described by Jérôme Lejeune in 1963. The condition affects an estimated 1 in 50,000 live births across all ethnicities and is more common in females by a 4:3 ratio. The syndrome gets its name from the characteristic cry of affected infants, which is similar to that of a meowing kitten, due to problems with the larynx and nervous system.
Follicular lymphomaFollicular lymphoma (FL) is a cancer that involves certain types of white blood cells known as lymphocytes. The cancer originates from the uncontrolled division of specific types of B-cells known as centrocytes and centroblasts. These cells normally occupy the follicles (nodular swirls of various types of lymphocytes) in the germinal centers of lymphoid tissues such as lymph nodes. The cancerous cells in FL typically form follicular or follicle-like structures (see adjacent Figure) in the tissues they invade.
OncogeneAn oncogene is a gene that has the potential to cause cancer. In tumor cells, these genes are often mutated, or expressed at high levels. Most normal cells will undergo a programmed form of rapid cell death (apoptosis) when critical functions are altered and malfunctioning. Activated oncogenes can cause those cells designated for apoptosis to survive and proliferate instead. Most oncogenes began as proto-oncogenes: normal genes involved in cell growth and proliferation or inhibition of apoptosis.
Chromosome segregationChromosome segregation is the process in eukaryotes by which two sister chromatids formed as a consequence of DNA replication, or paired homologous chromosomes, separate from each other and migrate to opposite poles of the nucleus. This segregation process occurs during both mitosis and meiosis. Chromosome segregation also occurs in prokaryotes. However, in contrast to eukaryotic chromosome segregation, replication and segregation are not temporally separated. Instead segregation occurs progressively following replication.
Copy number variationCopy number variation (CNV) is a phenomenon in which sections of the genome are repeated and the number of repeats in the genome varies between individuals. Copy number variation is a type of structural variation: specifically, it is a type of duplication or deletion event that affects a considerable number of base pairs. Approximately two-thirds of the entire human genome may be composed of repeats and 4.8–9.5% of the human genome can be classified as copy number variations.
Acute megakaryoblastic leukemiaAcute megakaryoblastic leukemia (AMKL) is life-threatening leukemia in which malignant megakaryoblasts proliferate abnormally and injure various tissues. Megakaryoblasts are the most immature precursor cells in a platelet-forming lineage; they mature to promegakaryocytes and, ultimately, megakaryocytes which cells shed membrane-enclosed particles, i.e. platelets, into the circulation. Platelets are critical for the normal clotting of blood.
