Tiny, Spontaneous Gene Mutations May Boost Autism Risk

Tiny gene mutations, each individually rare, pose more risk for autism than had been previously thought, suggests a study funded in part by the National Institute of Mental Health, a component of the National Institutes of Health.

These spontaneous deletions and duplications of genetic material were found to be ten times more prevalent in sporadic cases of autism spectrum disorders than in healthy control subjects — but only twice as prevalent in autism cases from families with more than one affected member. The results implicate the anomalies as primary, rather than just contributory, causes of the disorder in most cases when they are present, according to the researchers. Although they might share similar symptoms, different cases of autism could thus be traceable to any of 100 or more genes, alone or in combination.

“These structural variations are emerging as a different kind of genetic risk for autism than the more common sequence changes in letters of the genetic code that we’ve been looking for,” explained NIMH director Thomas Insel, M.D. “The best evidence yet that such deletions and duplications are linked to the disorder, these findings certainly complicate the search for genes contributing to autism. These are rare changes, dispersed across the genome, and they tell us that autism may be the final common path for many different genetic abnormalities.”

“Our results show conclusively that these tiny glitches are frequent in autism, occurring in at least ten percent of cases, and primarily in the sporadic form of the disease, which accounts for 90 percent of affected individuals,” added Sebat. “Understanding such sporadic autism will require different genetic approaches and stepped-up recruitment of families in which only one individual has the disease.”

Sebat and colleagues used new high resolution array technology to detect mutations that were present in a child but not in either parent. They screened genetic material from 264 families drawn, in part, from the Autism Genetic Resource Exchange (AGRE) and the NIMH Center for Collaborative Genetic Studies of Mental Disorders.

They found the spontaneous mutations in 14 of 195 people with autism spectrum disorders compared to two of 196 unaffected individuals. Among the 14 autism patients with mutations, 12 were the only affected members of their family, while two were in families with other affected individuals.

Since the rate of mutations was much lower in families with more than one affected member, the researchers propose that “two different genetic mechanisms contribute to risk: spontaneous mutation and inheritance, with the latter being more frequent in families that have multiple affected children.”

The two mutations detected in 196 healthy controls were duplications, while 12 of those in people with autism were deletions of genetic material. Relatively more females had the mutations, suggesting that the anomalies may contribute to disease more equally across the sexes than other causes of autism. Boys with autism outnumber girls 4 to 1.

Since each mutation is individually rare — few were seen more than once — the results suggest that many different sites in the genome likely contribute to autism. “Failure to develop social skills and repetitive and obsessive behavior may in fact be the consequence of a reaction to many different cognitive impairments,” note the researchers.

The new study is part of a growing body of NIH-funded research on autism genetics. For example, researchers last fall reported discovery of a gene version linked to autism and how it likely works at the molecular level to increase risk. The new study was also supported by the Simons Foundation, Autism Speaks, Cure Autism Now, Southwestern Autism Research and Resource Center, NAAR, Tampere University Hospital Medical Fund.

Autism and Deafness

Two instances that impair this free communication and dialog between people are autism and deafness. These two are often confused with the other. Autism may be misdiagnosed as deafness and vice versa. Sometimes though, a child can actually turn out to be both autistic and deaf.

Autism

Autistic children are regarded as children who live in their own world. The condition displays lack of proper communication skills and repetitive behavioral patterns. Some may think that they are stuck to being such but actually these children are capable of observing and learning too, only in their own way. There is a need for the people around the kid, the family, to understand the world of the child.

Deafness

This condition manifests in the inability of a person to hear and understand speech. The problem may stem from birth defects or diseases like ear infections. As a result of the disability, the child will have a difficulty of learning to speak and comprehend.

Autism and Deafness

The lack of capability to communicate and relate in both cases actually poses the difficulty of diagnosing the condition. They often get mixed up! Most parents might think that the unresponsiveness of their kids are due to hearing defects.

It was found by recent studies that 30% to 50% of autistic people turn out to be deaf too. There could actually be more out there, we just happen to treat them as one that we ignore already the symptoms that point to the other condition.

What basically are the differences?

Deafness may be fixed by operation or hearing aids, while autism can not be. Autism will have to be addressed properly to give way to a brighter future to the child.

Deaf kids can still comprehend through their eyes. They can perceive through their sight, the only problem is that they can't hear. An autistic child on the other hand may actually be able to see and hear, but they act like they are deaf because they do not respond. They simply cannot respond.

Kids with hearing disorder can still express themselves in many ways. They can watch other people. They can signify their feelings through gestures. They sometimes are able to make sounds if they are happy or if they are hurt. An autistic child may not be able to do this.

Address the situation properly. Instead of ignoring the symptoms and delaying the confrontation of the dilemma at hand, the situation of the child should be prioritized.

Seek for the help and assistance of experts. Once you saw the symptoms, do consult the experts right away, whether you suspect it as deafness or autism or both.

Send your child to special institutions. There are many institutions out there that cater to providing special education to autistic and deaf children. Make sure also that you yourself are able to attend seminars and consultations so you will understand better the situation.

Maintain a support group that will constantly give you strength and courage when things get rough. There are known associations and committees that actually help parents and family members of children who are both deaf and autistic.

Dealing with deafness and autism may really pose great challenges to the family. There may be pains and frustrations as your child struggle to express, to communicate or to learn. What matters though is that you are there as someone who will listen, someone who will reciprocate and someone who will affirm.

Autism Talk

I have started a brief discussion about autism on my other blog recently. Then I thought it might be better if I made another one dedicated only to talk about autism... Autism Talk! Yup, at least we will have more spaces than just a label :-P.

So, let's just get started. As my first post, I will talk about "What Is Autism?"

Autism is a chronic brain disorder characterized by difficulty with social interaction, verbal skills and communication, repetitive and narrow interests, and often violent reactions to changes in the environment. There is no known cause, though some scientists and researchers suspect a genetic abnormality, injury to the brain or exposure to an environmental toxin.

Autism is most often diagnosed in early childhood, between the ages of 12 and 36 months. That's when most parents begin to notice that their child is not developing speech and communication skills normally, or that they may have disturbed social interactions. Children with milder forms of the disorder may not be diagnosed until they begin school, and for some, even later, at the beginning of middle school, when social and communication skills become more important.

Autism is a commonly used term to describe any one of five pervasive developmental disorders, collectively known as 'autism spectrum disorders'. There are numerous theories about how the disorders relate to each other (we will discuss more about this later). Some researchers believe that they are separate disorders which have similar symptoms, while others feel that there exists a 'spectrum' of severity that ranges from extremely mild (like many children with Asperger's syndrome) to incapacitating. The five pervasive developmental disorders are autism, Asperger's syndrome, Rett Syndrome, childhood disintegrative disorder (CDD), and pervasive developmental disorder not otherwise specified.

Autism - symptoms appear before age 3, though they may not be diagnosed till much later. Symptoms include difficulty making or maintaining eye contact, disturbances in social functioning and an overwhelming self-absorption.

Asperger's syndrome - like autism, symptoms appear before age 3. Asperger's children and adults are more likely to be higher functioning and capable of independent or supported living. Symptoms include difficulties in social functioning, difficulties in communication and speech, and an absorption in narrowly defined interests. Some children with Asperger's syndrome are savants in some area.

Rett Syndrome - afflicts almost exclusively girls. The child usually develops normally for 6-18 months, then shows a marked loss of skills. Acquired speech is lost, and the child may be unable to control her hands and feet. Rett Syndrome can be tested for with 80% accuracy.

Childhood disintegrative disorder - A child develops normally through 2-4 years, then shows a marked degeneration in social, physical, mental and verbal skills. The long period of normal development marks the difference between autism and CDD.

Pervasive developmental disorder not otherwise specified - is diagnosed when there are impairments in social interaction, stereotyped behavior and communication, but the child doesn't meet the criteria for one of the other four disorders.