Autism testing (Under construction!)
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Home DNA Testing Autism’s Link To A Chromosome 16 Mutation http://www.dna-testing-home.com/autisms-link-to-a-chromosome-16-mutation/28/ Autism is a brain development disorder and behaviors of those who have autism range from: hindered or impaired social interaction and communication; repetitive behavior such as hand-flapping, body rocking or head rolling; compulsive behavior such as arranging objects according to size, shape or color; the dislike of change; ritualistic behavior; self-injury; all starting before a child is three years old. Up to this date, diagnosis has always been based on behavior – the child must exhibit at least six symptoms, such as lack of social or emotional reaction, repetitive use of language, problems with all types of communication and a fixation with objects. Autistic children may fail to respond to their name and often avoid eye contact with others. They have difficulty interpreting what people are thinking or feeling because they can’t understand social cues, such as tone of voice or facial expressions, and they don’t watch other people’s faces for clues about appropriate behavior. In a nutshell, they lack empathy. Unfortunately, Autism is a common disease and effects approximately 1 in 150 births, according to the Centers for Disease Control and Prevention in 2007. This means as many as 1.5 million Americans today are believed to have some form of autism. Based on statistics from the U.S. Department of Education, autism is growing at an alarming rate of 10-17 percent per year, and affects all races and ethnicities. At this rate, it is estimated that autism could affect 4 million Americans in the next decade! And although the overall incidence of autism is consistent around the globe, it is four times more prevalent in boys than in girls. So how does Autism occur? What causes it to happen? This has been an ongoing debate for quite a long time. According to Carolyn Abraham from the Globe and Mail (January 10, 2008):Two independent research teams have pinpointed the genetic glitch behind certain cases of autism, paving the way for the first DNA test to reliably predict who will develop the disorder. Researchers with the Boston-based Autism Consortium have found that children who carry a missing or duplicated stretch of chromosome 16 have a 100-fold increased risk of developing autism. The mutation, confirmed through genetic scans of more than 1,400 people with autism in three separate study groups, appears most often to be the result of a random quirk not seen in either parent. Published in today’s New England Journal of Medicine, the Boston paper estimates the mutation is linked to about 1 per cent of all autism cases. If the genetic code in this region is deleted – like a sentence missing several words – it cannot be read, said Dr. Scherer, and this seems to result in more severe cases of autism. If the code is duplicated, the disorder appears to be milder – like a sentence in which repeated words make it difficult, but not impossible, to read. According to Dr. Scherer, “The link between the mutation and autism is so strong that it will herald “ the first highly predictive DNA test for an autism disorder. We are transferring the technology [to perform the test] from our research lab to the diagnostic clinic as we speak.” Interestingly enough, other types of mutations at Chromosome 16 have been identified as responsible for diseases such as: Crohn’s Disease; Inflammatory bowel disease, tuberous sclerosis, Charcot-Marie-Tooth disease, polycystic kidney disease and others. Now Autism can be added to it’s list. As previously stated, in the past Doctors have relied on behavior to diagnose the disease. However, with this new technology, an inexpensive DNA test could identify those who are still in the womb, or infants who are suspected to have the disease. No doubt this pre-birth identification will generate either a positive, or negative, controversial reaction from people, depending on their beliefs. Children’s Hospital in Boston is now also offering the test for the Chromosome 16 mutation for Autism. Blood test to diagnose autism could be ready in three years http://www.dailymail.co.uk/health/article-1285349/Autism-blood-test-available-years.html A simple test that could revolutionise the diagnosis of autism could be available within just three years. The kit would use a few drops of blood to help doctors decide if a child has the devastating condition, speeding up diagnosis and allowing life-altering treatment to start earlier. The test, which Oxford University researchers believe could be in NHS clinics by 2013, would capitalise on the results of a landmark genetic study into the root causes of autism. In the largest study of its kind, 120 scientists and doctors from 50 universities around the world compared the DNA of more than 1,000 children with autism and their parents with the genetics of more than 1,300 other people. They found that in autism, large chunks of DNA are likely to be duplicated or erased, damaging genes and interrupting their vital work. The children involved had many different insertions or deletions - known as copy number variants - but the end result was the same, the journal Nature report. Some of the damaged genes are key to the development of the brain and the transmission of messages. Although some were known to be involved in autism before, others have been implicated in the condition for the first time. Autism and related conditions such as Asperger's syndrome affect more than one in 100 British children - ten times as many as just 30 years ago. With the causes unclear, diagnosis is a lengthy and stressful process of hospital visits and psychological tests, and there are not drugs that can tackle the condition at it root. The latest research shines a light on the causes, providing scientists with the information they need to formulate drugs and create blood tests. Experts said it brought hope of a 'brighter future' to the millions of families who struggle with autism every day. Canadian researcher Dr Stephen Scherer said: 'The results will lead to a paradigm shift when it comes to understanding the root causes of autism.' Professor Tony Monaco, who led the Oxford team, likened autism research to trying to put together a jigsaw - with the latest findings equivalent to the vital pieces that make up the edges. He said: 'This consortium of scientists and clinicians has really been trying to put together a very large jigsaw puzzle without having the benefit of a nice colourful picture on the box. 'In this paper the copy number variants that we have found were probably the easiest thing we could have found. They frame this jigsaw puzzle, they are the pieces with the edges. 'And they give us an idea of what the picture may look like because you can group them together and say that some are representing the sky or the ocean or the sand of the picture.' Tests that pick up copy number variants are already used in the diagnosis of learning disabilities and the professor and Newcastle University colleagues are poised to carry out a pilot study of a test for autism. He said: 'Just knowing about these genetic changes can help families come to terms with why their child has autism but can also be important where there are siblings too in determining future risk.' The results would allow parents to be counselled on the odds of their having a further child with the condition. However, it would only pick up 15 to 20 per cent of cases - although further genetic studies could improve on this. Trinity College Dublin researcher Dr Louise Gallagher said: 'Currently autism diagnosis is entirely behavioural and lengthy and parents are subjected to a long process where their child is being assessed and some children are not getting a diagnosis until as late as five years old. 'With earlier detection these children could get earlier interventions which may limit the severity of the condition.' Dr Geri Dawson, of US charity Autism Speaks, which part-funded the study, said: 'These findings bring hope to many families who struggle with autism every day.' Dr Jenny Longmore, of British charity Autistica, which also provided funding, said: 'It is a giant leap forward.' But the National Autistic Society cautioned that the fruits of the research were a long way off - and said that autistic children and adults need more support in the here and now. For instance, many children with autism are not receiving the help they need to deal with associated mental health problems such as depression and obsessive compulsive disorders. The charity's Dr Gina Gómez de la Cuesta said: 'Research into autism is constantly evolving but the exact causes are as yet still unknown. 'The difficulty of establishing gene involvement is compounded by the interaction of genes with the environment. 'Genetic testing for autism is still a long way off, given that autism is so complex. 'Whilst it is very important that research continues, it is also crucial that those living with the condition have access to appropriate advice and information, as the right support at the right time can make an enormous difference to people's lives.' Scientists at Imperial College London are also developing a diagnostic test but it is based on research showing that people with autism have different bugs in their guts from others. If it is true, it could dismiss or confirm claims that vaccines cause it (by doing these genetic tests before and after vaccinations). Read more: http://www.dailymail.co.uk/health/article-1285349/Autism-blood-test-available-years.html#ixzz1K088TZ2A Autism Genetic Test Doesn’t Answer Most Parents’ Questions http://health.usnews.com/health-news/blogs/on-parenting/2010/03/15/autism-genetic-test-doesnt-answer-most-parents-questions From the headlines, you'd think that the new genetic test for autism described today in the journal Pediatrics will give parents of children with autism the answers they so desperately seek. Not so, alas. Although this test identifies more children who have genetic abnormalities associated with autism, it doesn't nail down the cause of about 90 percent of autism cases. Right now, children suspected of having autism are tested for genetic abnormalities with two tests: the G-banded karyotype, which looks for abnormalities in the chromosomes, and fragile X testing, which looks for a specific variation on the X chromosome. Those two tests find genetic abnormalities in up to 5 percent of children with autism. In the new study, researchers used a newer test, chromosomal microarray analysis, to identify variations in much smaller chunks of DNA. That test turned up genetic abnormalities in about 7 percent of people with autism spectrum disorders, compared with about 2 percent of people tested with the karyotype method. The researchers, affiliated with institutions that are part of the Autism Consortium of Boston, point to that 5 percentage point difference and argue that the newer genetic test should be used widely in diagnosing children with autism. However, even with the better genetic test, about 90 percent of children diagnosed with autism will have no known genetic cause of their condition. We simply don't yet have tests capable of finding the subtle genetic cues that play a role in autism, alhtough children with more severe forms of autism or mental retardation are more likely to have identifiable genetic abnormalities. "Undoubtedly, autism has a genetic basis," says Robert Marion, director of clinical genetics at Montefiore Medical Center in New York and author of Genetic Rounds. "The fact that we've poured billions of dollars into research and have come up with virtually nothing that is really helpful tells me that the mechanism involved in causing autism is different than the standard single-gene mutation" that people think of as causing a genetic disorder. Indeed, Marion and other researchers think that the genetic causes of autism lurk in the 95 percent of human DNA that doesn't code for proteins but rather controls how and when genes are switched on and off. Scientists are just starting to figure out how that epigenetic process works. And since many of the genetic variations identified in people with autism appear to be unique to that person, it will take a lot more testing and research to figure out cause and effect. "Autism is not one syndrome or one condition," Marion says. "It's a common pathway that is led to by a number of problems that affect the way the brain works." At this point, he says, we know something is "screwed up" but not how or why. So, the more precise genetic tests can be helpful to a small number of parents, sparing the family time and worry en route to a speedier diagnosis. But for the other 90 percent of autistic kids, their parents can only wait for answers. New Improved Genetic Testing for Autism Study finds chromosomal microarray analysis detects more abnormalities March 15, 2010 A newer type of genetic test is better at detecting abnormalities that predispose a child to autism than standard genetic tests, new research has determined. Researchers offered about 933 people aged 13 months to 22 years who had been diagnosed with an autism spectrum disorder three genetic tests: G-banded karyotype testing, fragile X testing or chromosomal microarray analysis (CMA), which has been available only for the past few years. Karyotype tests identified chromosomal aberrations associated with autism in about 2 percent of patients, while the fragile X genetic mutation was found in about 0.5 percent of patients. CMA detected chromosomal abnormalities in slightly more than 7 percent of patients, making it the best available genetic test for autism spectrum disorders, the study authors said. "The CMA test alone has triple the detection rate of karyotyping or fragile X," said co-senior author Bai-Lin Wu, director of the Genetics Diagnostic Laboratory at Children's Hospital Boston. "CMA should be added to first-tier genetic testing for autism spectrum disorders." The study appeared online March 15 and will be published in the April print issue of Pediatrics. "When parents have a child diagnosed with an autism spectrum disorder, one of the first questions they often ask is 'how did this happen?' " said Dr. Robert Marion, a pediatric geneticist at Children's Hospital at Montefiore Medical Center in New York City. "In the vast majority of cases, we believe there is at least a genetic predisposition to autism, but the ability to identify a specific genetic cause has been very elusive," Marion said. "Part of that is because of the technology that's been available. A larger part is at this point, we just don't fully understand what the genetic mechanism that leads to autism is." Standard practice is to offer children with autism two tests as a first-line genetic work-up: karyotype and fragile X testing, the researchers said. In karyotyping, forms of which have been around since the 1960s, geneticists use a microscope to look for chromosomal abnormalities that are associated with autism, explained Dr. David Miller, a clinical geneticist and assistant director of the Genetics Diagnostic Laboratory at Children's Hospital Boston, which conducted the new research along with Boston's Autism Consortium. Like karyotyping, CMA also looks for chromosomal abnormalities, but does so at 100 times the resolution of the earlier test, Miller said. CMA, a genome-wide test, can identify sub-microscopic deletions of duplications of DNA sequences, called copy-number variants, known to be associated with autism, he said. "Think of chromosomes as a library full of books and each book as a gene," Miller said. "What we look for are shelves of books that have gone missing, which represent a missing fragment of a chromosome, or extra fragments of chromosome, that could contain genes related to autism." While both Children's Hospital Boston and Montefiore have offered CMA testing for several years, not all hospitals do, nor does all insurance pay for it, the researchers noted. The main purpose of genetic testing of children with autism is to help parents determine if they're at a higher risk of having another child with autism, Marion said. If tests pinpoint an autism-related chromosomal abnormality in the child, the parents are then offered testing. If a parent is also found to have the abnormality, geneticists conclude that the couple is at higher risk of having a child with autism. (The precise risk depends on what the variant is.) But if the parents don't have the abnormality, geneticists conclude that the deletion or duplication happened by chance, and the parents are probably not at any greater risk of having another child with autism than the general population, Marion said. Still, there is much geneticists can't tell parents. Between 10 percent and 15 percent of autism cases can be traced to a known genetic cause, the researchers noted. Of that, CMA alone can detect 7 percent of those. There are a few other genetic tests that can explain another few percentage points of autism cases. But that leaves 85 percent or more families with little explanation for the disorder, Marion said. "CMA is better, but it's not great," Marion said. "The vast majority of children who have autism have no identifiable genetic markers that will help in genetic counseling for future pregnancies. That is very frustrating." More information http://www.ninds.nih.gov/disorders/autism/detail_autism.htm The U.S. National Institute of Neurological Disorders and Stroke has more on autism. SOURCES: Bai-Lin Wu, Ph.D, M.Med, director of the Genetics Diagnostic Laboratory at Children's Hospital Boston; David Miller, M.D., Ph.D., clinical geneticist and assistant director of the Genetics Diagnostic Laboratory at Children's Hospital Boston; Robert Marion, M.D., pediatric geneticist, Children's Hospital at Montefiore Medical Center, New York City; April 2010, Pediatrics From: http://www.businessweek.com/lifestyle/content/healthday/636945.html CMA Test Could Find More Autism Genes, Researchers Say http://abcnews.go.com/Health/AutismNews/autism-genes-test-find/story?id=10099178&page=2 "Compared to [these tests], this one worked more than three times as effectively," Wu said. "This may mean we detect much more genetic changes that we have not been able to find yet." What this could mean for parents is an end to the guilt that they may have harbored for their child's condition, said another of the study's co-authors, Dr. Leonard Rappaport, chief of the Division of Developmental Medicine at Children's Hospital Boston. "As in most things in life, people search for the reason why something happened," Rappaport said. "Mothers are still blamed for their children's developmental problems by extended families, and families blame themselves for secret things they do not even reveal to us. As we find diagnoses that cause ASD, people will worry less about things, such as immunizations, despite there being no data to support them." Autism experts not involved with the study agreed that adding this test to the current battery could help both families and doctors confront the risks and treatment of autism spectrum disorders. Dr. Nancy Minshew, professor of psychiatry and neurology and director of the University of Pittsburgh's Autism Center of Excellence, said the test could help parents of an autistic child determine the risk of having another child with autism in the future. Additionally, she said, families who have a child with autism "can benefit from the experience of all the other individuals with that same genetic defect to anticipate the course [of treatment] and to share in the knowledge of what therapies work." The researchers behind the study were also hopeful that the test could lead to the detection of more genes associated with autism -- and perhaps even begin to explain some of the mysteries behind why these conditions arise in the first place. "We hope that in the long term, the identifications of specific genetic causes will help us to determine what's going on in the brains of these children," Miller said, adding that one day this knowledge may even lead to specific treatments tailored to the genetic causes of autism from patient to patient. Autism Gene Glitch Traced to Moms Glitch in CNTNAP2 Gene May Be Passed Down by Mothers By Miranda Hitti WebMD Health News, Reviewed by Louise Chang, MD Jan. 10, 2008 -- Glitches in a gene called CNTNAP2 appear to be linked to autism, and at least one of those mutations may be handed down by mothers. That news appears in today's online edition of The American Journal of Human Genetics. In the journal, three teams of scientists identify CNTNAP2 as a possible autism gene. "The three studies together identify a set of common and rare variants that provide unequivocal evidence that the CNTNAP2 gene, when disrupted, leads to a subtype of autism spectrum disorders," states an editorial published with the studies. Here's a quick look at each study's findings. Mom's DNA. An autism-related CNTNAP2 gene mutation is inherited from mothers, not fathers, though autism is more common in boys than girls. So say researchers, including Dan Arking, PhD, of Johns Hopkins University School of Medicine. This study doesn't mean that moms are to blame for their child's autism; Arking's team looked for genetic patterns in DNA, not autism causes. Language link. A glitch in the CNTNAP2 gene is linked to language delay in autistic children. And the CNTNAP2 gene is active in brain areas related to language, say scientists, including Maricela Alarcon, PhD, of the UCLA Center for Autism Research and Treatment at the University of California, Los Angeles (UCLA). Multiple mutations. More than one CNTNAP2 mutation may be linked to autism, according to experts including Betul Bakkaloglu and Matthew State, MD, PhD, of Yale University's medical school. The CNTNAP2 gene is a "very large target for mutations," writes editorialist Dietrick Stephan, PhD, of the Translational Genomics Research Institute in Phoenix. But that doesn't mean that CNTNAP2 is the only gene involved in autism. The genetics of autism are complex, Stephan notes. Previous research suggests that 100 or more genes may affect autism risk. From: http://www.webmd.com/brain/autism/news/20080110/autism-gene-glitch-traced-to-moms |