Mitochondria are small organelles found in eukaryotic cells which respire aerobically. They are responsible for generating energy from food to ‘power the cell’. They contain their own DNA, reproducing by dividing in 2. As they closely resemble bacteria, it gave the idea that they were derived from bacteria (which were engulfed by ancestors of the eukaryotes we know today). This idea has since been confirmed from further investigations, and it is now widely accepted. (Alberts et al., 2010a)
The genes which encode for the mitochondria’s component proteins are in 2 separate genetic systems in 2 different locations. One of which is the cell nucleus, but the other is inside the organelle itself. There are relatively few genes inside the organelle, as most of the bacterial genes have been transposed to the cell nucleus. 16569 nucleotide pairs of DNA make up the human mitochondrial DNA, encoding 37 genes. (Alberts et al., 2010b). Both mitochondria and their DNA are inherited almost entirely from the mother. Mitochondrial DNA is more at risk from spontaneous mutation than DNA found in the cell nucleus. Some somatic effects associated with aging are potentially due to the accumulation of mutations in mitochondrial DNA. (Turnpenny and Ellard, 2012)
Mitochondria are essential in the cellular generation of ATP. This is because the genome encodes for 13 proteins, 2 ribosomal genes, and 22 tRNAs which are essential for this process in eukaryotic cells. Many maternally inherited diseases are due to germline mutations in mitochondrial DNA (mtDNA). But somatic mtDNA mutations may have great effects on aging and cancer. (Hartmann A, 2008)
Leber hereditary optic neuropathy (LHON) is caused by mtDNA mutations and is a maternally inherited disorder...
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...net, 48, 935-942.
9) Huoponen K, VilkkiJ, Aula P, Nikoskelainen E, Savontaus M (1991) Am. J. Hum. Genet, 48, 1147-1153.
10) Brown MD. (1999) The enigmatic relationship between mitochondrial dysfunction and Leber's hereditary optic neuropathy. J Neurol Sci. 165:1–5
11) Hudson G, Yu-Wai-Man P, Chinnery P F (2008) Leber hereditary optic neuropathy. Expert opinion on Medical Diagnostics. Vol 2, No. 7 p789-799.
12) Man, P. Y., et al. (2003) The epidemiology of Leber hereditary optic neuropathy in the North East of England. American Journal of Human Genetics 72, 333-339
13) Chial, H. & Craig, J. (2008) mtDNA and mitochondrial diseases. Nature Education
14) Man P Y W, Turnbull D M, Chinnery P F (2002) Leber hereditary optic neuropathy. J Med Genet 39, 162-169.
15) Taylor R W, Turnbull D M. (2005) Mitochondrial DNA Mutations in Human Disease, Nat Rev Genet. 389-402.
Percy, A. K. (1999). Inherited neurodegenerative disease: The evolution of our thinking. Journal of Child Neurology, 14(4), 256-62. Retrieved from
...s Elevated in Brain of Patients with Dominantly Inherited Olivopontocerebellar Atrophy. Neuroscience Letters (submitted publication).
Ivy is the third generation in her family to be affected by achondroplasia. Her grandfather, her father, and her brother also have it. Achondroplasia is inherited as an autosomal dominant trait whereby only a single copy of the abnormal gene is required to cause achondroplasia. Nobody with the mutated gene can escape having achondroplasia. Many individuals with achondroplasia have normal parents, though. In this case, the genetic disorder would be caused by a de novo gene mutation. De novo gene mutations are associated with advanced paternal age, often defined as over age 35 years. If an individual with achondroplasia produce offspring with a normal individual, the chances of the offspring inheriting the mutant allele achondroplasia is 50%. If both of the parents have achondroplasia, the chances that their offspring will be of normal stature a...
The disease Angelman Syndrome, named after the physician Harry Angelman, was first diagnosed in 1965. It is now known that the disease results from the loss of function of UBE3A, a gene. One is normally inherited from each parent. The copy inherited from the mother is active in certain areas of the brain. If this copy of the gene UBE3A is lost due to chromosomal change or gene mutation, the lost gene will not have active copies in parts of the brain. A majority (70%) of Angelman syndrome cases happen when a segment of the maternal chromosome 15 is lost or destroyed. A minority of the disease is caused by a mutation or loss of function of the mother’s copy of the UBE3A gene. The majority of cases result from uniparental disomy, which is when the son or daughter inherits two copies of chromosome 15 from his or her father. Translocation, or chromosomal rearrangement, can also cause the disease. Most cases of this disease are not inherited, instead are a result of deletion in the maternal chromosome 15. Across 1. 2 copies of chromosome 15 are inherited from the father Down 1 Person who first diagnosed this disease 2 Disease the magazine is about 3 A gene 4 a minority of this disease is caused by this 5 Chromosomal rearrangement DISEASE BACKGROUND PAGE 1
GeneticaLens - What is Angelman Syndrome? The History of the Diagnosis - Dr. Harry Angelman. (n.d.). Retrieved March 20, 2014, from http://www.angelmanproject.com/history.htm
In 1993 a consortium of researchers who worked on the DNA samples from families in the Lake Maracaibo region of Venezuela, an area with a high density of HD and significant consanguinity, reported the successful discovery of the gene responsible for the occurrence of this disease, present in chromosome 4 and named it as IT15 (Interesting transcript #15). IT15 later called as the Huntingtin gene (HTT) [2]. HTT is ~10 kilobases (kb) long and translated into a protein of 3144 amino acids with anticipated molecular mass of 348 kDa. Huntigtin protein is expressed in in human and all mammalian cells, where brain and testis has the highest concentration; liver...
Tishkoff, S. A., Goldman, A., Calafell, F., Speed, W. C., Deinard, A. S., Bonne-Tamir, B., Kidd, J. R., Pakstis, A. J., Jenkins, T., Kidd, K. K. A global haplotype analysis of the myotonic dystrophy locus: implications for the evolution of modern humans and for the origin of myotonic dystrophy mutations. Am. J. Hum. Genet. 62: 1389-14`02, 1998.
Lewis, Ricki, (2014), Human Genetics, 11th Edition, Chapter 12. Gene Mutation. [VitalSource Bookshelf Online]. Retrieved from
contained mitochondrial DNA (mtDNA), completely intact. Mitochondrial DNA is tougher than the DNA found in cell nuclei; it is also found in the cytoplasm of a fertilized egg and is passed only through maternal lineage. This makes it much easier for the team to study and makes testing more accurate.
9(3): 383-398. Keeney, Belea T. and Kathleen M. Heide. 1995.
The mitochondria produces food for the cell by converting energy the cell needs. The mitochondria and the nucleus are two organelles within a cell that have many of the same similarities. Both organelles are made of two membranes. These layers isolate within the organelle all things considered, yet have protein channels that permit things to go in and out. Both contain DNA material that conveys qualities that encode for proteins. Both have qualities that make ribosomes, the machines that read the guidelines in RNA to make
Amyotrophic lateral sclerosis, also known as ALS or Lou Gehrig’s disease, is a neurological disorder that affects roughly one in 200,000 people (DiDonato et al., 2003). As such, ALS is among the most common neurological disorders found in humans. It typically occurs mid-life and kills motor neurons, which leads to paralysis and death. Most cases of ALS do not show a genetic linkage. However, five to ten percent of cases are, in fact, inherited in an autosomal recessive manner (DiDonato et al., 2003). This inherited ALS is referred to as familial ALS (FALS), and twenty percent of these cases are connected to mutations in the SOD1 gene.
The mitochondria is an organelle which is generally an oval shape and is found inside the cytoplasm and is again apart of the eukaryotic cells. The main function of the mitochondria is to complete cellular respiration; in simple terms it acts like a digestive system to break down essential nutrients and to convert it into energy. This energy is usually found to in ATP which is a rich molecule taken from the energy stored in food. Furthermore, mitochondria stores calcium for signalling activities; such as heat, growth and death. They have two unique membranes and mitochondria isn’t found in human cells like the red blood cells yet liver and muscle cells are filled entirely with mitochondria.