41. Fragile X Syndrome - X-linked Mental Retardation And Macroorchidism Rapid Antibody Test for Prenatal Diagnosis of fragile x syndrome on Amniotic Fluid Cells Trinucleotide Repetition and fragile x syndrome http://ibis-birthdefects.org/start/frafact.htm

Report Broken Links Exchange Banners Contact Us Fragile X Syndrome See I.B.I.S in English Spanish Russian Ukranian Search Fragile X Syndrome - X-linked Mental Retardation and Macroorchidism Page Includes: FRAXA FRAXD FRAXE FRAXF Marker X Martin Bell X Fragile-Folic Acid type X-linked Mental Retardation and Macroorchidism X-linked Mental Retardation associated with marXq28 [*] Outstanding [P] For Professionals [S] Support Group [French] [German] [Italian] [Portuguese] [Spanish] [Swedish] [*][P] Fragile X Syndrome GeneClinics by J Tarleton and RA Saul. " ... characterized by moderate mental retardation in affected males and mild mental retardation in affected females ... all mothers of a child with an FMR1 gene full mutation (expansions >230 trinucletide repeats) are known to be carries of an FMR1 gene expandsion. They and their family members are at increased risk to have children with fragile X syndrome and should be offered DNA-based testing and recurrence risk counseling based on the results. This counseling is extremely complex and should be provided by a knowledgeable genetic professional. Prenatal testing is possible though analysis ... should only be undertaken after carrier status has been ... (1998)." [*][P] Fragile Site Mental Retardation 1 - FMR1 other Fragile X Mental Retardation mutations OMIM - comprehensive authoritative review mostly for Medical Geneticists.

42. Genomics|HuGENet|Fact Sheets|FMR1 And The Fragile X Syndrome The mission of the Office of Genomics and Disease Prevention is to integrate advances in human genetics into public health research, policy, and programs. http://www.cdc.gov/genomics/hugenet/factsheets/FS_FragileX.htm

home fact sheets FMR1 and the Fragile X Syndrome PUBLISHED: July 2001 AUTHORS: Dana C. Crawford ( zbn9@cdc.gov FMR1 GENE The fragile X mental retardation-1 ( ) gene, located at Xq27.3, codes for the mRNA-binding fragile X mental retardation protein (FMRP). FMRP is thought to shuttle select mRNAs between the cytosol and nucleus and is highly expressed in the brain, testes, ovaries, esophageal epithelium, thymus, eye, and spleen. PREVALENCE OF GENE VARIANTS For premutations (61-200 repeats), the estimates for Caucasian females range from 1 in 246 to 1 in 468 in the general population. To date, the smallest premutation to hyperexpand to the full mutation in a single generation is 59 repeats. If the threshold for premutations were lowered to 55-200 repeats, the prevalence among Caucasian females can be as high as 1 in 116, depending on the population studied. For Caucasian males, the prevalence of the premutation (61-200 repeats) is probably between 1 in 1,000 to 1 in 2,000 in the general population. No estimates exist for other racial/ethnic groups. DISEASE BURDEN The fragile X syndrome is the most common form of inherited mental retardation and accounts for approximately 40% of cases with X-linked mental retardation. Other characteristics of the fragile X syndrome include a wide range of cognitive, behavioral, and physical features such as variable IQ (profound to mild mental retardation), autistic-like features, hyperactivity, increased testicular volume, macrocephaly, and large ears. Females are less severely affected, presumably because of X-inactivation. In the United States, a child with the fragile X syndrome is eligible for early intervention and special education services. A screening study in a U.S. public special education population suggests that approximately 1 in 400 males receiving special education services are affected by the fragile X syndrome.

43. Genomics|HuGENet|Reviews|FMR1 And The Fragile X Syndrome The mission of the Office of Genomics and Disease Prevention is to integrate advances in human genetics into public health research, policy, and programs. http://www.cdc.gov/genomics/hugenet/reviews/fragilex.htm

home reviews FMR1 and the fragile x syndrome Archived: 6/28/2001 This paper was published with modifications in Gentics in Medicine 2001 Sep/Oct; 3(5): 359-71 PubMed ID: and the Fragile X Syndrome Dana C. Crawford, PhD , and Stephanie L. Sherman, PhD Centers for Disease Control and Prevention, Epidemic Intelligence Service, Division of Applied Public Health Training, Epidemiology Program Office Centers for Disease Control and Prevention, National Center on Birth Defects and Developmental Disabilities Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Division of Reproductive Health, CDC Assignee to the Louisiana Office of Public Health National University of Colombia Department of Genetics, Emory University School of Medicine, Atlanta, GA 30322. Corresponding Author : Dana C. Crawford, PhD Centers for Disease Control and Prevention National Center on Birth Defects and Developmental Disabilities 4770 Buford Highway NE, MS F-45

44. Your Child | Fragile X Syndrome Who should be tested for fragile x syndrome? Two types of tests are available to diagnose fragile x syndrome and to test for female carriers. http://www.med.umich.edu/1libr/yourchild/fragilex.htm

YOUR CHILD HOME Your Child Topics UMHS HOME Fragile X syndrome What is Fragile X syndrome? Fragile X is the most common inherited form of mental retardation. It affects about 1 in 1200 males of all racial and ethnic groups. It can cause a range of mental impairment- varying from mild to severe , and can also cause many other typical features and symptoms. Here is some basic information about Fragile X. To learn more about genetics and to better understand how genes cause syndromes, see Your Child: Gene t ic Syndromes What causes Fragile X syndrome? It is inherited. It is caused by mutation of a gene ( ) on the X-chromosome. Genetic testing for Fragile X is possible. Mothers may be a carrier of the mutation and pass it on to their children. Or, a mother may have a pre-mutation that expands to a full mutation when passed on to the next generation. Boys are affected more severely than girls, because girls have another X chromosome, which usually does not have the mutation and can partially compensate for the nonfunctioning one. Boys have only one X chromosome (and one Y chromosome). The damaged gene can be passed along silently for generations before a child is affected by Fragile X syndrome.

45. Pediatric Advisor 2004.2: Fragile X Syndrome fragile x syndrome is an inherited disorder. It can cause hyperactivity, fragile x syndrome is a genetic disorder caused by a mutation (a change in the http://www.med.umich.edu/1libr/pa/pa_fragilex_hhg.htm

Pediatric Health Topics All Health Topics Mott Children's Hospital Pediatric Services ... Find a UMHS Doctor Search Pediatric Topics Search All Topics This information is approved and/or reviewed by U-M Health System providers but it is not a tool for self-diagnosis or a substitute for medical treatment. You should speak to your physician or make an appointment to be seen if you have questions or concerns about this information or your medical condition. Index Fragile X Syndrome What is fragile X syndrome? Fragile X syndrome is an inherited disorder. It can cause hyperactivity, learning problems, and emotional problems. It can also cause mental retardation and autism, although some children with fragile X have normal IQs. This disorder is the most common known cause of inherited mental retardation and affects both males and females. What is the cause? Fragile X syndrome is a genetic disorder caused by a mutation (a change in the genetic information) of a specific gene. The parents or other family members did not do anything to cause it. The gene mutation has usually been carried unknowingly for many generations. Both males and female carriers can have a small fragile X mutation (called a premutation) and still be completely normal. The premutation can expand to a larger full mutation when it is passed on to the next generation through a female. It is the full mutation that causes fragile X syndrome. Your child may be the first one in your family with behavior or development problems, or there may be other relatives who are affected by the fragile X mutation. Your doctor or a genetic counselor will explain how this gene mutation is passed on in your family and who should be tested for it.

46. Fragile X Syndrome a CHORUS notecard document about fragile x syndrome. http://chorus.rad.mcw.edu/doc/02033.html

CHORUS Collaborative Hypertext of Radiology Multisystem entities About CHORUS Search Feedback fragile X syndrome chromosomal abnormality mild familial mental retardation findings: normal to increased head size macroorchidism protruding ears prominent jaw Michael A. Woo-Ming, MPH - 2 February 1995 Last updated 26 May 2004 Related CHORUS documents: Cockayne syndrome progeria (Hutchinson-Gilford) syndrome blueberry muffin sign central pontine myelinolysis ... Hurler's syndrome Search for related articles: AJR American Journal of Roentgenology PubMed : index to biomedical literature ... Medical College of Wisconsin

47. Understanding Fragile X Syndrome With The Blink Of An Eye While researchers have long known the genetic defect underlying fragile x syndrome, they are still tracing how that defect creates the complex mix of mental http://www.eurekalert.org/pub_releases/2005-08/cp-ufx072805.php

Public release date: 3-Aug-2005 E-mail Article Contact: Heidi Hardman hhardman@cell.com Cell Press Understanding Fragile X syndrome with the blink of an eye While researchers have long known the genetic defect underlying Fragile X syndrome, they are still tracing how that defect creates the complex mix of mental retardation, hyperactive behavior, attention deficits, and other problems in the disorder. Fragile X is particularly important because it is the most common single-gene cause of mental retardationaffecting about 1 in 4000 males and 1 in 8000 females in the U.S. In an article in the August 4, 2005, issue of Neuron , researchers led by Chris De Zeeuw of Erasmus University Rotterdam report that they have pinpointed a specific cause of defects in motor learning in Fragile X patients. Their work represents the first investigation of the role of abnormalities in the brain's cerebellum in Fragile X syndrome. Fragile X syndrome is caused by a defect in the Fragile X mental retardation 1 (Fmr1) gene, which in turns produces a nonfunctioning protein, FMRP. In their studies, De Zeeuw and colleagues studied the behavioral effects on motor learning and the effects on neurons in the cerebellum of knocking out this gene. They found that mice lacking the gene showed deficits in a particular motor learning task known to be largely controlled by the cerebellum. In this "eyeblink conditioning" task, the mice were taught to associate a stimulus such as a tone with a puff of air on their eye, and the blink response was measured as an indication of how well the animals could learn the task. The researchers found that mice completely lacking the Fmr1 gene showed deficits in the motor learning task. But most importantly, the researchers also found that mice lacking the Fmr1 gene only in specific neurons, called Purkinje cells, in the cerebellum showed the deficit.

48. Fragile X Syndrome - DrGreene.com Read about a genetic disease that is the most common cause of mental retardation in boys. http://www.drgreene.com/21_1096.html

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49. FRAGILE X SYNDROME : Contact A Family - For Families With Disabled Children: Inf Contact a Family is a UK charity for families with disabled children. We offer information on specific conditions and rare disorders. http://www.cafamily.org.uk/Direct/f33.html

printer friendly FRAGILE X SYNDROME home how we can help medical information index of conditions ... how you can help Did you find this page helpful? yes no Fragile X is the most common identifiable form of inherited learning disability . It has a prevalence of about 1 in 4,000 males and 1 in 8,000 females. The cause is an abnormality just above the tip of the X chromosome's long arm, which may be passed from one generation to the next. Intellectual disability varies from mild to severe. Girls and women who have a fragile X chromosome are often of normal intelligence. However up to a third have learning problems which are usually mild or moderate but can occasionally be severe. Other problems experienced by affected individuals include delayed and distorted speech and language development. There can be difficulties with the social use of language, with continuing speech anomalies, repetitive behaviour, attention deficits and overactivity, and autistic-like features, such as poor eye contact, hand flapping, social anxiety, abnormal shyness and an insistence on routine. Physical features ascribed to fragile X syndrome include a relatively large head, a long face with prominent ears, largish jaw and double-jointedness. However these are rarely obvious in affected individuals. 10-30 per cent of people with fragile X syndrome develop

50. Fragile X Syndrome Article describes fragile x syndrome, its symptoms, diagnosis, and treatment. http://rarediseases.about.com/cs/chromosomeproblem/a/050704.htm

var zLb=8; var zIoa1 = new Array('Elsewhere on the Web','National Fragile X Foundation','http://www.fragilex.org/home.htm','FRAXA Research Foundation','http://www.fraxa.org/','NICHD: Families and Fragile X Syndrome','http://www.nichd.nih.gov/publications/pubs/fragileX/index.htm'); zJs=10 zJs=11 zJs=12 zJs=13 zc(5,'jsc',zJs,9999999,'') zfs=0;zCMt='a70' About Rare / Orphan Diseases Rare Diseases E - H Rare Diseases: F Fragile X Syndrome Rare Diseases Essentials Rare Diseases: Basic Information Rare Diseases Support Groups ... Help zau(256,140,140,'el','http://z.about.com/0/ip/417/C.htm','');w(xb+xb+' ');zau(256,140,140,'von','http://z.about.com/0/ip/496/6.htm','');w(xb+xb); FREE Newsletter Sign Up Now for the Rare / Orphan Diseases newsletter! See Online Courses Search Rare / Orphan Diseases Stay up to date! Compare Prices Email to a friend ... Print this page Elsewhere on the Web National Fragile X Foundation FRAXA Research Foundation NICHD: Families and Fragile X Syndrome Most Popular Muscular Dystrophy ALD and Lorenzo's Oil Progeria Syndromes Leprosy (Hansen's Disease) ... The Elephant Man What's Hot Muscular Dystrophy Autoimmune Kidney Disease Minamata Disease Charcot-Marie-Tooth Disease ... Meckel-Gruber Syndrome adunitCM(150,100,'x55')

51. Public Health Genetics Unit: Fragile X Syndrome Implications of current knowledge of the genetics of fragile x syndrome fragile x syndrome affects about 1 in 4000 males and 1 in 8000 females. http://www.phgu.org.uk/info_database/diseases/fragile_x/fragilex.html

Text-only sitemap Home About Newsletter ... Search Fragile X syndrome See Explanatory Notes Contents Genetics Implications of current knowledge of the genetics of Fragile X syndrome Genetic testing for Fragile X mutations Genetic screening ... On-line information Fragile X syndrome affects about 1 in 4000 males and 1 in 8000 females. The major features are learning disability of varying severity, behavioural problems such as hyperactivity and autistic tendencies, and physical characteristics including long face, protruding ears, lax joints and (in males) enlarged testes. There is no cure but there is some evidence that treatment of the associated behavioural and educational problems can be beneficial. Genetics Fragile X syndrome is caused by mutation of the FMR-1 gene on the X chromosome . The FMR-1 gene contains a sequence that consists of a variable number of repeats of the trinucleotide CGG. This sequence occurs in a part of the gene that is transcribed but is not translated into protein. The normal number of CGG repeats varies between 5 and about 50 (average around 30). Individuals with fragile X syndrome typically have more than 200 of these repeats, a condition known as a full mutation (FM). The full mutation prevents transcription of the FMR-1 gene, so that none of its protein product is made. Males have only one X chromosome, so if they carry a FM they are always affected. Females have two X chromosomes and the result of a FM in one chromosome can be very variable: about 50% of such females show some symptoms of the syndrome and 20% are severely affected.

52. Fragile X A boy with fragile x syndrome. Note the prominent and elongated ears and This diagram displays fragile x syndrome. This occurs in about 1 in 1500 males. http://medgen.genetics.utah.edu/photographs/pages/fragile_x.htm

Fragile X Syndrome view 110KB version view 8KB version A boy with fragile X syndrome. Note the prominent and elongated ears and long face. Children from different ethnic groups have similar characteristics. This picture shows a Caucasian boy. view 1378 KB version view 5KB version This picture is of an Asian boy with fragile X syndrome. view 1864 KB version view 13 KB version This picture is of an Hispanic boy with fragile X syndrome. This diagram displays fragile X syndrome. This occurs in about 1 in 1500 males. Affected female carriers are typically normal. Most of the affected males have mental retardation, and their testes are larger than normal. Examinations Photographs Movies Links ... noJava Home

53. Www.ddhealthinfo.org - Medical Care Information fragile x syndrome is the most common inherited cause of mental The prevalence of fragile x syndrome in males is approximately 1 in 3600 in the general http://www.ddhealthinfo.org/ggrc/doc2.asp?ParentID=3169

54. Diagnosis And Management Of Fragile X Syndrome - July 1, 2005 - American Family The first review in this series discusses fragile x syndrome. The diagnosis of fragile x syndrome is confirmed by molecular genetic testing of the FMR1 http://www.aafp.org/afp/20050701/111.html

Advanced Search AAFP Home Page Journals Diagnosis and Management of Fragile X Syndrome DANIEL J. WATTENDORF, MAJ, MC, USAF, and MAXIMILIAN MUENKE, M.D., National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland This article exemplifies the AAFP 2005 Annual Clinical Focus on the legal, social, clinical, and ethical issues of medical genomics. See editorial on page 33 A glossary of genomics terms is available online at http://www.aafp.org/afp/ genglossary.xml A PDF version of this document is available. Download PDF now (3 pages /162 KB). F ragile X syndrome is caused by an expansion mutation in the Fragile X mental retardation 1 gene located on the X chromosome. It characteristically leads to some degree of mental retardation. The phenotype is subtle, with minor dysmorphic features and developmental delay during childhood. Characteristic features during adolescence are an elongated face, prominent jaw, large ears, macro-orchidism, and a range of behavioral anomalies and cognitive deficits (Figure 1).

55. Fragile X Syndrome: Definition And Much More From Answers.com fragile x syndrome n. An inherited disorder caused by a defective gene on the Xchromosome and causing mental retardation, enlarged testes, and. http://www.answers.com/topic/fragile-x-syndrome

showHide_TellMeAbout2('false'); Business Entertainment Games Health ... More... On this page: Dictionary Medical Term Medical Wikipedia Best of Web Mentioned In Or search: - The Web - Images - News - Blogs - Shopping fragile X syndrome Dictionary fragile X syndrome n. An inherited disorder caused by a defective gene on the X-chromosome and causing mental retardation, enlarged testes, and facial abnormalities in males and mild or no effects in heterozygous females. It is the most common inherited cause of mental retardation. Medical Term Fragile X syndrome One of the most common causes of inherited mental retardation and neuropsychiatric disease in human beings, affects as many as one in 2000 males and one in 4000 females. The syndrome is also known as FRAXA (the fragile X chromosome itself) and as the Martin-Bell syndrome. However, the preferred name is fragile X syndrome. The characteristic features of the fragile X syndrome in boys include prominent or long ears, a long face, delayed speech, large testes (macroorchidism), hyperactivity, tactile defensiveness, gross motor delays, and autistic-like behaviors. Much less is known about girls with fragile X syndrome. Only about half of all females who carry the genetic mutation have symptoms themselves. Of those, half are of normal intelligence, and only one-fourth have an IQ under seventy. Few fragile X girls have autistic symptoms, although they tend to be shy and quiet.

56. Inclusive Technology - Fragile X Syndrome fragile x syndrome is the most common inherited cause of learning disability (mental The Fragile X Society produce two booklets fragile x syndrome An http://www.inclusive.co.uk/support/fragilex.shtml

home catalogue search downloads ... support organisations Fragile X Syndrome The following information is provided by The Fragile X Society. What is Fragile X? Fragile X Syndrome is the most common inherited cause of learning disability (mental handicap). It occurs more in boys than in girls and is associated with varying degrees of learning difficulty. Boys who are affected almost always have some learning difficulty ranging from mild learning difficulties to severe handicap. Girls are often of normal intelligence but up to a third have learning problems which may be mild or moderated but are occasionally severe. The behaviour features include short attention span, distractibility, impulsiveness and overactivity. Shyness and social withdrawal are often seen in girls who may have difficulties in making friends. Many show autistic-like features - a dislike of eye contact, difficulty in relating to other people, anxiety in social situations often leading to tantrums, insistence on familiar routines and hand flapping or hand biting. Speech and language is usually delayed with continuing speech difficulties and some children and adults develop epilepsy.

57. Development And Neurobiology: Genetics Of Childhood Disorders: Fragile X Syndrom fragile x syndrome is a common form of mental retardation with an estimated incidence of Individuals with fragile x syndrome manifest neurodevelopmental http://info.med.yale.edu/chldstdy/plomdevelop/genetics/00febgen.htm

J Am Acad Child Adolesc Psychiatry,39:2, 264-266 February 2000 Stephan Eliez, M.D., and Allan L. Reiss, M.D. Fragile X syndrome is a common form of mental retardation with an estimated incidence of 1 per 2,000 to 4,000 in the general population. The physical manifestations associated with the syndrome include macroorchidism, large ears, a prominent jaw, moderate to severe mental retardation, and autistic-like behavior. However, physical features are not always reliable indicators of the presence of the condition, particularly in prepubertal children and females. For years, investigators had noted that the phenotype of fragile X syndrome cosegregated with an unusual disruption of the X chromosome. Karyotyping of cells grown in folate-depleted cell culture media revealed that many patients had a ³fragile² site on one of their X chromosomes that appeared as a constriction on the distal long arm. This genetic syndrome is of particular interest to clinicians and scientists who want to understand brain development and function in children. Individuals with fragile X syndrome manifest neurodevelopmental abnormalities that include varying levels of cognitive dysfunction, particularly in the domains of executive, visual-spatial, and visual motor abilities, and frequently display behavioral symptoms of autism, attention-deficit/hyperactivity disorder, and social anxiety. Morphological variations of brain structure have been observed in this population and include abnormalities in the cerebellar vermis, caudate, hippocampus, and lateral ventricles.

58. InteliHealth: Fragile X Syndrome InteliHealth Featuring Harvard Medical School s consumer health information. For more than 550 diseases and conditions, learn What Is It?, Symptoms, http://www.intelihealth.com/IH/ihtIH/WSIHW000/9339/9603.html

chrome_imgPreload('gifChr_mid_but_home_mo_1','http://img.intelihealth.com/i/C/Chr_mid_but_home-o.gif'); chrome_imgPreload('gifChr_mid_but_comm_mo_2','http://img.intelihealth.com/i/C/Chr_mid_but_comm-o.gif'); chrome_imgPreload('gifChr_mid_but_dental_mo_3','http://img.intelihealth.com/i/C/Chr_mid_but_dental-o.gif'); chrome_imgPreload('gifChr_mid_but_drug_mo_4','http://img.intelihealth.com/i/C/Chr_mid_but_drug-o.gif'); chrome_imgPreload('gifChr_mid_but_askexpert_mo_5','http://img.intelihealth.com/i/C/Chr_mid_but_askexpert-o.gif'); chrome_imgPreload('gifChr_mid_but_medical_mo_6','http://img.intelihealth.com/i/C/Chr_mid_but_medical-o.gif'); chrome_imgPreload('gifChr_mid_but_chats_mo_7','http://img.intelihealth.com/i/C/Chr_mid_but_chats-o.gif'); chrome_imgPreload('gifchr_mid_but_news_mo_8','http://img.intelihealth.com/i/c/chr_mid_but_news-o.gif'); chrome_imgPreload('gifChr_mid_but_privacy_mo_9','http://img.intelihealth.com/i/C/Chr_mid_but_privacy-o.gif'); Advertisement Fragile X Syndrome What Is It? Symptoms Diagnosis Expected Duration ... Additional Info What Is It? Fragile X syndrome is an inherited disorder associated with mental retardation and a particular appearance. It results from an error in a small piece of the DNA (genetic blueprint) for the FMR-1 gene. This gene is found on the X chromosome, one of the two chromosomes, X and Y, that determine gender.

59. Fragile X For years, mystery shrouded fragile x syndrome, a form of mental impairment. In patients with fragile x syndrome, a gene, which should hold a string of http://apu.sfn.org/content/Publications/BrainBriefings/fragile.x.html

Login Directory Merchandise Contact Us ... Abstracts/Annual Meeting Publications Full size image available below Fragile X For years, mystery shrouded fragile X syndrome, a form of mental impairment. Since the biological roots of the disease were unknown, traditional therapies have centered on treating the behavioral characteristics of the disease. For example, attention problems often are treated with central nervous system stimulants that are used for attention-deficit hyperactivity disorder. But the 1991 discovery of the genetic error that underlies fragile X has electrified scientists. A series of new studies is leading to treatments that can target the biomedical malfunctions, specifically. You added 10 teaspoons of Tabasco sauce instead of one. One cookbook typo certainly changed the outcome of your chili. Errors in the recipe for a human - or genes - carry even greater consequences. Inherited disorders, including a form of mental impairment called fragile X syndrome, result from alterations in the code in genes. Normally, molecules in the genes efficiently encode and guide the production of proteins. These proteins, in turn, guide the development and function of the body and brain. In patients with fragile X syndrome, a gene, which should hold a string of three coding molecules that repeat six to 50 times, is over-expanded. The misprint can include 200 to more than 1,000 copies of this one particular "triplet" sequence. The excess muddles the instructions needed for the creation of a specific protein. The result? The level of fragile X protein in a person with the syndrome is low or nonexistent - the lower the level, the greater the mental impairment. Side effects range from mild learning and attention disabilities to severe mental retardation.

60. Stanford Psychiatry Neuroimaging Laboratory: Fragile X fragile x syndrome is a common hereditary cause of mental retardation and learning disability. Both males and females can be affected by fragile x syndrome, http://spnl.stanford.edu/disorders/fragilex.htm

What is fragile X syndrome? Fragile X syndrome is a common hereditary cause of mental retardation and learning disability. Both males and females can be affected by fragile X syndrome, although females often have milder effects. Males with fragile X syndrome usually have mental retardation, and may have some autistic-like behaviors. Females with fragile X syndrome may have mental retardation or learning disabilities, social difficulties, and anxiety What causes fragile X? Fragile X is caused by mutations of a gene called the gene. These gene mutations can affect the development of specific regions of the brain and make a person more susceptible to developing cognitive and behavioral difficulties. Individuals with the full mutation of the gene have fragile X syndrome, while individuals with the premutation of the gene usually are usually not affected. Individuals with the premutation, however, are at risk for having a child with the full mutation and fragile X syndrome. The figure above shows the most common fragile X mutation- an expansion of extra DNA within a specific component of the gene. In the premutation, the expansion is relatively small, however, in the full mutation the expansion is quite large and is usually accompanied by abnormal methylation. The presence of abnormal methylation leads to decreased production or absence of the

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