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Unformatted text preview: s are carriers of the gene with full mutation which caus es the fragile X syndrome. 5. How does the full mutation affect the activity of th e FMR1 gene? What protein is not produced as a result? Full mutation causes the gene to shut down or met hylate a region of the FMR1 gene. When the gene is tur ned off, the protein that is unable to be produced is the fragile X mental retardation protein (FMRP). 6. What are two molecular tests that can be used in dia gnosing Fragile X Syndrome? Which one is the best for determining the full mutation? The Southern Blot analysis and the poly chain reac tion (PCR) were available during the 1970s and 1980s a s a way to diagnose fragile X syndromes. The one suite d for determining full mutation of the syndrome is the Southern Blot analysis. 7. What happens to premutations in subsequent generati ons? Which parent, father or mother, is more likely to pass a permutation that will do this? Premutations are identified when an individual has 60-200 CGG repeats and can occur in both females and males. A common feature of this gene is its ability to c hange sizes throughout generations. It can appear frequ ently or severely in subsequent generations. Females, m others, are more likely to pass the premutation gene to off springs while males are able to pass it only to daug hters. The mutation is located on the X chromosome. 8. What is the penetrance of fragile X phenotypes (cog nitive defects, behavioral, social functioning) for fema les with the full mutation? 30% of females with the full mutation show no sig ns of cognitive deficits. 65-70% of females with the ful l mutation will show signs of difficulty with cognitive, behavioral, or social functioning and may possess physi cal features found in males. 9 . W h a t i s t h e p r o b a b i l i t y t h a t CHNKWKS @ ø ÿÿÿÿ TEXT TEXT d/ FDPP FDPP 2 FDPP FDPP 4 FDPC FDPC 6 FDPC FDPC 8 SGP STSH STSH : X STSH STSHX: SYID SYIDø: µ SGP ; INK INK ; BTEP BMKT PLC ¤; p STRS ˆ TITL TITLŽ? - DOP 25 points ________________ due 2/21 Fragile X Syndrome PLC µ; BTEC PLC 4; FONT FONTT; P PLC µ< : PRNT WNPRN< ¸ FRAM FRAM? DOP ¬? " o r m e t h y l a t e H o m e w o r k # 3 : name ___________________ Go to the site for the National Fragile X Foundation at http://www.fragilex.org/html/home.shtml Click on the "What is Fragile X" link and answer the fo llowing 1. What is the name of the gene that is mutated in the genetic conditions known as Fragile X? The gene that is mutated in the genetic condition i s called the FMR1 gene. Click on Fragile X Syndrome read the info and answer the following 2. What is the major manifestation of this condition? ales very ntal this Males are more likely to carry this gene while fem are less likely. The syndrome occurs in 1 out of e 3600 males and 1 out of 4000 to 6000 females. Me instability is the likely cause of the inheritance of gene. 3. What are two behavioral characteristics found in mal es with this condition? The two characteristics found in males are physica l and behavioral. Physically, males would appear to hav e elongated faces with a prominent chin, enlarged ears, and large testicles. Connective tissues can also cause a variety of skeletal and other problems with joints. Beha viorally, symptoms can include, hand biting, hand flapp ing, attention deficit disorders, speech disturbances, po or eye contact, autistic behavior and unusual responses to touch, audio and visual stimuli. 4. What are the three forms of the FMR1 gene and what results from each? The three forms of the FMR1 gene is coded in lette rs, CGG, which are repeated in a pattern of DNA. Indiv iduals with less than 60 CGG repeats are considered nor mal and don t carry the mutation. Those who have 60-20 0 CGG repeats have pre-mutation which means that they carry the unstable mutation and can pass it to future ge nerations. Individuals with over 200 CGG repeatan offs pring (include both males and females together) of each of the following couples will have fragile X syndrome ( resulting from making no FMRP)? (you will need info fr om the Inheritance section as well as info obtained fro m clicking on the FMRP link under cause , near the end of the paragraph in that section). a. Male with full mutation x Female with only normal c opies of the FMR1 genes. 1/2 b. Male with normal FMR1 gene x Female heterozygous for the full mutation and a normal allele. 1/2 c. Male with normal FMR1 gene x Female homozygous f or the full mutation. 1 Go to OMIM at the following URL: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=OMI M Type in FMR1 and hit go 10. What is the gene map locus? (use the one under the first entry for the gene) The gene map locus is the FRAXA located at Xq.27 .3 which is a fagile site, frolic acid type, rare, fra(X) (q27.3) A (macroorchidism, mental retardation.) Go to the National Center for Biotechnology Informatio n Website at http://www.ncbi.nlm.nih.gov/ Click on Genomic Biology (in the blue strip on the lef t) Under Map Viewer- genome annotation updates , click o n Homo sapiens Click on the X chromosome (on the X indication) Under Compress Map, Region Shown: , type in the map location for the FMR1 gene (gene map locus above) into both of the boxes (indicates start and stop points) and hit go . You should now see an expanded region of the X chromosome including the FMR1 gene. Click on g FMR1 and use the info to answer the followin 11. What are three names that FMR1 is also known as? It is also known as FMPR; FRAXA; MGC87458 Scroll down to GeneOntology Under Function Click o n the Pubmed link in line with protein binding . Click o n the link (list of authors names) for the 2006 article (second one in the list of 2). Read over the abstract an d answer the following 12. What is the name of the first author of the study? (first one in the list) Ramos A 13. What does FMRP bind and what process is it involv ed in? The FMRP is a molecular RNA binding protein and it is involved in the process of posttranslational regula tion. 14. What are the authors reporting on? (what did they s olve?) (don t need to include details) The authors are reporting on the importance of the N-terminal domain of FMRP (NDF). They solved that th e NDF composite fold (two repeats of a Tudor motif fol lowed by a short alpha helix) determines the regulation s the FMRP functions. ene x Female heterozygous for the full mutation and a normal allele. 1/2 ...
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- Winter '07