Quiz 2 Diseases Flashcards
What is Mosaicism? What is it caused by? Symptoms?
When an individual has two different genotypes. Caused by error in cell division early in embryonic life. Severity depends on normal cells: abnormal cells ratio.
What is Thalassemia? What is it caused by? Symptoms?
Underproduction of hemoglobin. Caused by over 400 mutations in HBB gene. Disrupts development of RBC’s, therefore lack of oxygen in tissues. Organ failure and poor growth as a result.
What is Methemoglobinemia? What is it caused by? Symptoms?
Alters the hemoglobin within RBC’s. Caused by over 10 mutations in HBB gene.
What is Sickle Cell Anemia? What is it caused by? Symptoms?
Mutations in the HBB gene causing an abnormal version of beta-globin to form, called HbS. The subunits of Hbs stick together, giving RBC’s a sickled shape. This causes the cells to die prematurely, and also cause pain for the patient when moving through capillaries, along with organ damage from blocked capillaries.
What is Hemoglobin C disease? What is it caused by? Symptoms?
Glu6Lys mutation. Causes two hemoglobin c subunits. Symptoms are anemia and premature lysis of RBC’s. Common in people of Western African descent.
What is Hemoglobin D disease? What is it caused by? Symptoms?
Gly26Lys mutation. Causes two hemoglobin e subunits. Can be concurrent with thalassemia and symptoms can present as such. Common in people with Eastern Asian descent.
What is Duchenne Muscular Dystrophy? What is it caused by? Symptoms?
Absence or defect of dystrophin mostly caused by X-linked mutation (1/3 of cases random mutation). Chronic muscle weakening leading to paralysis and death by 20’s.
What is Leber’s hereditary optic neuropathy? What is it caused by? Symptoms?
Partial or complete loss of central vision. Caused by 1 of 3 mtDNA point mutations affecting NADH dehydrogenase, which starves the retinal ganglion cells of energy and they lose ability to transmit signals to brain.
What is MERRF? What is it caused by? Symptoms?
Myoclonic epilepsy and ragged red fibers. Caused by mtDNA mutation in the tRNA encoding for lysine which disrupts synthesis of cytochrome C oxidase. Symptoms include ataxia and seizures.
What is MELAS? What is it caused by? Symptoms?
Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes. Most commonly inherited mitochondrial disease. Caused by mutation in tRNA gene for leucine, which disrupts synthesis of Cyt-C and Complex I. Many symptoms, but mainly nervous system and muscles.
