This web page was produced as an assignment for Genetics 564, an undergraduate course at UW-Madison.
What is a gene?
Inside each and every one of your cells is a nucleus, and inside your nucleus are 46 chromosomes, for a human. 23 of these chromosomes are from your mother and the other 23 from your father. In your nucleus, you have 2 copies of each chromosome, in exception to the sex chromosomes where a female is XX and a male is XY. Inside each of these chromosomes is your DNA, which is heavily compacted. Your DNA is made up of a sugar phosphate backbone and nucleotides (C, G, A, and T). A gene is comprised of a specific sequence of nucleotides from your DNA. Each gene undergoes a process deemed the Central Dogma to become a protein that performs a necessary function in your body. Below, and throughout the FLNB gene pages, I discuss more in depth the gene that causes Larsen Syndrome.
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Where is the FLNB gene located?
The proven gene that results in Larsen Syndrome is FLNB, commonly called Filamin B. A series of missense variants along FLNB cause Larsen Syndrome, though the exact number and location of these variants have yet to be thoroughly identified (1, 2). 13 known variants have been identified along FLNB thus far but from small sample sizes (1-3).
Larsen Syndrome is an autosomal dominant disorder where only one allele of the patients two FLNB alleles needs to be affected to contribute to the disorder (4). This FLNB gene is found on chromosome 3 on the short p arm at 14.3 (Figure 2). In terms of base pairs on chromosome 3 the FLNB gene is from 58,008,399 to 58,172,254 base pairs (3). |
References:
1.) Krakow, D., et al., (2004). "Mutations in the gene encoding filamin B disrupt vertebral segmentation, joint formation and skeletogenesis". Nature Genetics, 36(4), doi: 10.1038/ng1319
2.) Bicknell. L. S., et. al., (2007). "A molecular and clinical study of Larsen Syndrome caused by mutations in the FLNB". Journal of Medical Genetics, 44(1), doi: 10.1136/jmg.2006.043687
3.) Genetics home reference: FLNB. http://ghr.nlm.nih.gov/gene/FLNB accessed February 15, 2014.
4.) Gupta, N., and Kabra, M.,"Larsen Syndrome." Indian Pediatrics. 45(9) 2008: 783-4.
2.) Bicknell. L. S., et. al., (2007). "A molecular and clinical study of Larsen Syndrome caused by mutations in the FLNB". Journal of Medical Genetics, 44(1), doi: 10.1136/jmg.2006.043687
3.) Genetics home reference: FLNB. http://ghr.nlm.nih.gov/gene/FLNB accessed February 15, 2014.
4.) Gupta, N., and Kabra, M.,"Larsen Syndrome." Indian Pediatrics. 45(9) 2008: 783-4.