Working together, the group of 23 scientists from the US, Canada, and Israel are researching markers, both behavioral and biomedical, that indicate ASD. The earlier the markers are isolated, the earlier treatment for autism can begin. The researchers are not only working toward the goal of early identification, but also toward the development of treatments to prevent symptom development.

Because siblings of children with ASD are at a risk for ASD that is possibly as high as 10 times greater than that of the general population, studying siblings of autistic children presents a unique opportunity for researchers to identify autism very early in a child’s life. The research into the underlying mechanics of autism also affects clinical practices for children diagnosed with ASD.

Research is ongoing; new studies are planned to investigate environmental and genetic risk factors as related to autism, and a study of more than 1500 infant siblings of children with ASD is planned.

Results of this ongoing research will shed light on both risk factors connected to developing ASD as well as underlying causes of autism. While no one cause has been identified, the more research that is done, the closer we are to identifying causes and to developing new treatments that will ensure a positive outcome for children with ASD.

Read more about The High Risk Baby Siblings Research Consortium here.

Research led by Harvey J. Kliman, M.D., research scientist in the Department of Obstetrics, Gynecology & Reproductive Sciences at the Yale School of Medicine and reported in the June 26, 2006, online issue of “Biological Psychiatry” is shedding light on pathologic findings in the placentas of children with autism spectrum disorder (ASD).

The research group designed a study to determine if the presence of trophoblast inclusions in the placenta, a placental abnormality, is a marker for ASD. The researchers, using microscopic examinations of placental tissues, discovered that the placentas from ASD children were three times more likely to have these inclusions.

Kilman reports that “We knew that trophoblast inclusions were increased in cases of chromosome abnormalities and genetic diseases, but we had no idea whether they would be significantly increased in cases of ASD. These results are consistent with studies by others who have shown that ASD has a clear genetic basis.”

Trophoblast inclusions appear to be the result of abnormal cell growth in the placenta. Kliman offers the analogy of these inclusions as akin to a check-engine light on a car’s dashboard: “When the light goes on it simply means that something is not right. If the light is on and there is, for example, steam coming from under the hood, then it is likely that the radiator is leaking. However, if the check engine light is on and there is nothing obviously wrong, then the car should be carefully checked.”

Larger studies are in the works; the Yale team plans to examine the placentas in greater detail. They will examine the placentas of the children in the study in greater detail to gain insight into the biological basis of the inclusions in ASD.

Fred R. Volkmar of the Yale Child Study Center states that “If the work is confirmed by the next series of studies, then the finding of trophoblast inclusions at the time of birth in the absence of any obvious genetic abnormalities would be an indication to have a child examined by a specialist to determine the presence of ASD.”

While initial screening for ASD may be performed by a child’s pediatrician, additional screening and diagnoses are generally done by a specialist. The earlier a diagnosis is made, the earlier treatment and interventions can begin. The study of these placental abnormalities may lead to earlier diagnoses.

There is no one known cause of autism, but the Autism Society reports that “it is generally accepted that it is caused by abnormalities in brain structure or function.” Brain scans of children with autism show differences in the shape and structure of the brain as compared to normally developing children.

Genetics may play a role in the development of autism. No single gene has been identified as a cause of autism, but some families have a pattern of autism. Some children, it appears, are born susceptible to autism. Research is being conducted on whether some genes may interfere with brain development that results in autism, and whether problems during pregnancy or delivery may play a role.

Researchers are also studying whether environmental factors play a role in the development of autism. Metabolic imbalances, exposure to certain chemicals, and viral infections may be related to the development of autism.

Individuals who have certain medical conditions such as Fragile X syndrome, congenital rubella syndrome, untreated phenylketonuria (PKU), and tuberous sclerosis have been found to have autism more frequently, leading researchers to believe there may be a connection between these conditions and autism. Also associated with an increased risk of autism are some harmful substances ingested by pregnant women.

Heavy metals such as mercury are more prevalent in our environment today than they have been in the past. Individuals who have ASD or are at risk for developing it have a decreased ability to detoxify and metabolize these toxins.

Research regarding the link between vaccines and autism, however, has not been proven by research. The Centers for Disease Control and Prevention has conducted numerous studies on the safety of vaccines and the link between thimerosol, a preservative used in vaccines. The studies have found the there is no association between autism and vaccines.

So what causes autism? There are theories worthy of further research that may help uncover causes and connections, but at this point, there is no one identified cause of this complex syndrome.

ASD covers a range of symptoms, abilities, and behaviors, all of which relate to emotional and social development and to communication skills. Some people without ASDs may have some of the symptoms, but those who do have ASD will exhibit enough symptoms, in a severe enough form, that their daily life is very challenging.

No one tool is used to diagnose an ASD, and there is no medical test to rule out an ASD. Again, because autism is a syndrome, it is the confluence of several symptoms together that result in a diagnosis.

Some symptoms of ASD are:

Not playing “pretend” or “make believe” games;

Not pointing at objects of interest or looking at objects when pointed out;

Having no interest in others;

Avoiding eye contact with others;

Appearing unaware when spoken to but responding to other sounds;

Having trouble expressing needs using typical motions or words;

Preferring not to be held or cuddled;

Repeating actions over and over;

Having unusual reactions to tastes, smells, and sounds;

Losing skills once mastered (e. g. not using words previously used).

Parents and caregivers are often the first to notice one or more of the symptoms of an ASD. Following that observation, health care providers can observe the child and use diagnostic tools to assess them.

There are many tools available to assist in diagnosis of autism. Because autism is a syndrome, no one tool should be used for diagnosis. Some diagnostic tools include the Autism Diagnosis Interview–Revised (ADI–R), the Autism Diagnostic Observation Schedule – Generic (ADOS–G), the Childhood Autism Rating Scale (CARS), and the Gilliam Autism Rating Scale (GARS).

Making parents aware of normal development and development milestones, making health care providers aware of early diagnosis and treatment, and encouraging parents to discuss milestones with health care providers can help facilitate an awareness of when such milestones are not being reached. The earlier the diagnosis is suspected and confirmed, the earlier treatment and intervention can begin.

Autism is one of many pervasive developmental disorders (PPDs) and is often referred to as autism spectrum disorder (ASD). The acronyms used to describe autism can, in themselves, be confusing. The term Pervasive Developmental Disorder (PPD) (of which autism is the most well-known), refers to a group of developmental conditions affecting children that encompasses impairments and delays in social skills and communication. All PPDs affect communication, behavior, cognitive, and social skills, but they are not all alike. Most PPDs are diagnosed by age 3. Autism diagnoses are based on observation of behavior, not on medical tests.

Autism Spectrum Disorder, or ASD, is the term we usually hear when we read about autism. As the term “spectrum” implies, there are degrees to which individuals are affected by autism, and the term ASD is used to encompass a range of severity of symptoms. Two children may share the same diagnosis, but they may exhibit different degrees of behavioral symptoms.

How does Autism Affect Children?

Most useful for parents, though, is not so much what terminology is used to describe autism, but rather how the disorder manifests itself and affects those who have this complex neuro-biological impairment. As the Autism Society of America reports, “Both children and adults with autism typically show difficulties in verbal and non-verbal communication, social interactions, and leisure or play activities.”

Children on the autism spectrum have difficulty interacting with or playing with others. These difficulties include avoiding eye contact or being averse to being held or touched. Delays in development of physical, cognitive, social and emotional skills and language acquisition and use (or the achievement and then loss of developmental skills) are also hallmarks of autism.

What Causes Autism?

Although research is ongoing, there is currently no consensus as to the cause of autism. Genetics and environmental factors may play a role in the development of the disorder, but research has not established any definitive links.

There has been much speculation about whether thimerosal (mercury)-containing vaccines can cause autism. No research has found a link between vaccines and autism, and nearly all vaccines have been thimerosal-free since 2001. Researchers do know that parenting styles are not a factor in whether a child is affected by autism.

Is there a Cure for Autism?

There is no definitive cause of autism, and there is no cure for autism. Treatments and interventions can greatly improve the symptoms of autism, particularly if treatment begins very early in a child’s life. Because early intervention is so crucial, early diagnosis is essential.

Autism is a lifelong disability, but keep in mind that there is a difference between being incurable and being untreatable: autism is absolutely a treatable disorder. Early diagnosis, followed by early intervention, gives those affected by ASDs the best opportunity to receive treatment that will improve their symptoms.

What if I Suspect Autism?

If you suspect that your child may be affected by autism, the first course of action is to see your pediatrician right away. If your child has not received a routine developmental assessment, then request one. Determining if a child is meeting the developmental guidelines for his or her age is a crucial first step in determining if further screening is necessary.

Learn to determine what are credible sources regarding autism, read all that you can, and be prepared to report to your child’s pediatrician specific details about your child’s behaviors. If you are not getting answers to your questions, keep pressing until you do. Request a referral to a specialist, seek the opinion of another doctor, and stay informed about autism research.

You are your child’s best advocate, so if you feel something is not right, don’t be afraid to question your child’s pediatrician and advocate for the care your child needs.

Resources & References:

Visit the National Institute of Child Health and Human Development website here.

Also read Autism Speaks’ & What is Autism?

The findings of this study, conducted by researchers at the University of California, San Diego (UCSD) School of Medicine and Children’s Hospital and Health Center, is meaningful in terms of earlier diagnosis that can lead to earlier intervention and therefore to improved outcomes for children diagnosed with autism.

Autism is usually diagnosed by age 3; diagnosis is made base on observation of behavior, not a medical test. The earlier the diagnosis is made, the earlier treatment can begin. The early warning sign of increased brain growth occurs before behavioral symptoms of autism are noted.

Researchers in the UCSD study found that the rapid brain growth in children with autism means that “when the brain is experiencing the world and deciding how to construct itself, it’s growing too fast in the infant with autism,” according to the study’s senior author Eric Courchesne, Ph.D. In short, the brain cannot keep up with experiences and information and this makes “it very hard for autistic children to make sense of the world they live in,” says Courchesne.

The more excessive the brain growth, the more severe autism is, according to study results.

Researchers studied medical records of 48 children aged 2 to 5 who have an autism diagnosis; head circumferences were compared to the Centers for Disease Control and Prevention’s growth charts for normal development. The findings were that, on average, the head circumference of autistic children at birth was smaller than about 75 percent of other newborns. However, in the first year, these children had a rapid growth in brain size, reaching the 85th percentile (only 15 % of other newborns had a smaller head size) at around 1 year to 14 months old. Then, brain growth slowed.

Courchesne explains: “This burst of overgrowth takes place in a brief period of time, between about two months and six to 14 months of age. So, we know it cannot be caused by events that occur later, such as vaccinations for mumps, measles and rubella or exposure to toxins during childhood.”

This study, according to Courchesne, “provides, for the first time, a developmental process to target for animal model studies of the disorder. Animal models that accurately mimic these abnormal growth events will be necessary in order to discover causes and biological treatments for autism. Once we know what causes this specific growth defect, it may be possible to use biological treatments to successfully intervene before the overgrowth begins, thereby allowing the brain and behavior to develop down more normal paths.”

While certain other conditions such as hydrocephalus or certain metabolic disorders can cause a large head circumference, they are much less common than autism.

Research has found that experience-guided growth is beneficial to human brain development. Experiences that pass through certain pathways in the brain lead to higher order neurobehavioral functions and skills, such as motor skills, linguistic, emotional, and cognitive skills.

The findings of this study have positive implications for treatment. Courchesne states, “Using our findings as an early indicator of autism, intervention might begin two or three years earlier when the brain might be at a more malleable stage and so, might result in a better outcome for the child.”

While all it takes to measure head circumference and, consequently, brain size, is a tape measure, not all pediatricians include this in routine visits. The research team advocates routine head circumference measures in the first year of life.

In 2007, the results of the largest-ever genome scan were published. Performed by over 120 scientists working in more than 50 research institutions that comprise the Autism Genome Project, the research began in 2002 as a collaboration to identify genes that may cause autism.

Funded by Autism Speaks, the research team used looked for genetic similarities in the DNA from nearly 1,200 families. Findings of the study included the discovery that neurexin 1, part of a family of genes previously linked to autism, and a gene on chromosome 11 may be linked to autism.

In addition, researchers believe there may be as many as 30 genes involved in autism. In short, if a child has one or more of these indentified genes, then he or she has a higher risk of being born with autism.

Clearly, ongoing research is necessary in order for researchers to get closer to pinpointing a particular gene or genes that are implicated in autism. The next phase of the Autism Genome Project will continue to try to isolate genes that cause autism. The earlier autism is diagnosed, the earlier treatment and intervention can begin; early treatment is imperative in helping children with autism diagnoses to lead more fulfilling lives. Finding causes of autism is a positive step toward early diagnosis.

Resources & References

Read the National Institute of Mental Healh’s press release here.

Visit the Austism Genome Project’s website here.

While there are no known causes of autism, research into causation is ongoing. One such causal connection being explored is a genetic cause of autism.

A study at the David Geffen School of Medicine at UCLA has uncovered genetic connections between autism and speech delays. Funded by the National Institute of Mental Health, National Institute of Neurological Disease and Stroke, Cure Autism Now Foundation and UCLA Center for Autism Research and Treatment, the study was lead by Dr. Daniel Geschwind; the findings of the study were published in The American Journal of Human Genetics’ January 10, 2008, online edition.

This study follows an earlier one of DNA samples from families with an autistic child; that study revealed that autism was connected to a specific region of Chromosome 7 (called 7q35). In the next study, researchers studied genes from DNA samples from 172 families. The region’s implication in autism was confirmed by a subsequent study.

A key finding, according to Dr. Geschwind, is that the gene the research isolated, called contactin-associated protein-like 2 (CNTNAP2), “not only may predispose children to autism, [but . . .] also may influence the development of brain structures involved in language, providing a tangible link between genes, the brain and behavior.”

Postdoctoral fellow Brett Abrahams, who led part of the research, states that the research discovered that “CNTNAP2 concentrated in the brain’s structures that are involved in higher cognition gives us strong clues about how its disruption might adversely shape brain development, including speech and language”

Another finding was statistical evidence that the gene is strongest in families with autistic boys than in those with girls or with boys and girls.

Further effects of the study may be discoveries about whether CNTNAP2 has a role in language development in normally developing children.

While research into the causes of autism is ongoing and no one cause has been found, research such as this brings us closer to an understanding of this complex disorder.

A study released in April, 2009, has found that there is a gene variant common among 20 percent of children with autism and that may have a role in 12 to 18 percent of autism cases. The DNA was found in the fontal cortex, the region of the brain where language and communication is housed.

While there is no cure for autism, there are effective treatments and interventions. The results of this new study may impact successful treatments. Gerard Schellenberg, a professor at the University of Pennsylvania School of Medicine, the study’s author, states that “When we think about treatments, those target molecules and you have to know what to target. This is a major jump in terms of knowing what we need to look at.”

The molecules on the variant gene help to shape the developing brain’s structure, and the gene variant this study found acts as a link between the brain’s wiring and the child’s development. Found on chromosome 5, the gene variant occurs in normally developing children as well. Researchers think that there may be other high-risk variants at work in autistic children.

A second study by a research group led by Hakon Hakonarson from the Center for Applied Genetics at the Children’s Hospital of Philadelphia, replicated the results of the first study and examined the link between genes that help eliminate connections between nerve cells. The results of the study underscore the theory that abnormal connections between nerves in the brain cause autism.

“Both studies implicated genes involved in synaptic generation and neuronal connectivity,” Hakonarson said. “This is highly consistent with previously published research.”
Hakonarson also posits that environmental factors have a role in autism.

Recently, the National Institutes of Health has made autism a priority research topic and has pledged $60 million to research into the differences within the range of autism spectrum disorders. Research will focus on developing screening tools, assessing risks, and adapting existing interventions to best help treat children with an autism diagnosis.

These findings challenge a study that previously held that brain abnormalities in autistic children resulted from their brain’s faster development.

The technique used in this study measured the water properties of brain tissue. In the normally developing brain, water is incorporated into neurons rapidly for the first 6 months of life, and then slows for the next 18 months. The University of Washington study found that, in the autistic brain, water was more mobile. This finding suggests a delay in the development of neurons, specifically at the grey matter at the brain’s surface.

Dager suggests delays could be caused by inflammation: “If you’ve got inflammation, it can affect connectivity at a critical stage of brain development.” This inflammation during the first year of life could lead to learning problems. “For example,” Dager states, “a child has certain key developmental stages for learning language and if you miss those it can be harder to learn that language.”

This early inflammation, Dager suggest, may be due to a particular gene. Research into genetic links to autism is ongoing, but Matthew Belmonte, senior research associate at the Autism Research Center at the University of Cambridge asserts that “Until we know exactly what it is that causes the abnormal development of grey matter we cannot develop drug treatments.” Belmonte suggests that “One might look at genes that cause a susceptibility to inflammation instead [of brain changes].”

Whatever the focus of the research, learning more about the causes of this complex disorder can only help researchers to develop more, and more effective, treatment and intervention possibilities.