But surprisingly, fathers did pass on substantially more than 50% of their variants. This suggests that autistic children might have inherited risk variants in regulatory regions from their fathers but not their mothers, the researchers report today in Science.
When autism (or Aspergers) runs in families it is clear that they are at least partially inherited from the parents and/or the extended family. The parents or other family members may not necessarily have a diagnosis, but are carriers of genetic anomalies which in combination may cause autism in their offspring.
The cause of Asperger syndrome, like most ASDs, is not fully understood, but there is a strong genetic basis, which means it does tend to run in families. Multiple environmental factors are also thought to play an important role in the development of all ASDs.
In families without a history of autism spectrum disorders, the chance of having a child with one of these disorders is approximately 0.7 percent.
Genetic Heterogeneity of Susceptibility to Asperger Syndrome
Two X-linked forms, ASPGX1 (300494) and ASPGX2 (300497), are associated with mutation in the NLGN3 gene (300336) and the NLGN4 gene (300427), respectively.
Boys are three to four times more likely than girls to have Asperger's Syndrome. Most cases are diagnosed between the ages of five and nine, with some diagnosed as early as age three.
Study Finds 80% Risk From Inherited Genes. A new study looking at autism in 5 countries found that 80 percent of autism risk can be traced to inherited genes rather than environmental factors and random mutations.
The team found that mothers passed only half of their structural variants on to their autistic children—a frequency that would be expected by chance alone—suggesting that variants inherited from mothers were not associated with autism. But surprisingly, fathers did pass on substantially more than 50% of their variants.
The mutations are recessive, which means that they lead to autism only if a person inherits them in both copies of the gene — one from each parent, who are silent carriers. Most other mutations implicated in autism are spontaneous, or 'de novo,' mutations, which are not inherited.
If someone in your family has autism spectrum disorder (ASD), you may be more likely to have a child with ASD. ASD can look very different from person to person, so taking a careful family health history can be important for early diagnosis.
Asperger's, or “high-functioning” autism, is likely even more familial than autism at other points along the spectrum. Family members of people with Asperger's are also more likely to show behavioral symptoms similar to those seen in autism even if they haven't received a diagnosis.
Despite early theories suggesting the possibility, we now know that parenting style does not cause any of the Autism Spectrum Disorders. The number of individuals affected by Asperger's Syndrome is not well known, as an accurate diagnosis can be difficult to make.
No one thing causes Asperger's syndrome. However, research suggests that certain factors during pregnancy and after birth may put a child at higher risk of an autism spectrum disorder diagnosis. Those factors include: A chromosomal abnormality (such as fragile X syndrome).
They might exhibit an odd posture or have a stiff, rigid gait. Infants may show a delay in learning how to crawl or walk, and may also exhibit a delay in fine motor movements, such as grasping an object. Reflex Abnormalities— Infants with Aspergers appear to demonstrate abnormal reflexes versus normal kids.
The Likely Answer: There's No Single Cause
While the exact cause of Asperger's isn't known, many experts believe the disorder is probably triggered by a variety of factors. A combination of genetic, neurological, and environmental issues might work together to cause the syndrome.
Asperger's syndrome is lifelong. But symptoms tend to improve over time. Adults with this condition can learn to understand their own strengths and weaknesses. And they can improve their social skills.
Genome-wide linkage studies and cytogenetic studies suggest several chromosomal regions, including 2q, 7q and 15q, for linkage with autism and ASD. While the 7q region is considered the most promising in autism, linkage studies in Asperger syndrome have failed to observe its linkage to this region.
Some of the other genes in which rare mutations are associated with ASD, often with other signs and symptoms, are ARID1B, ASH1L, CHD2, CHD8, DYRK1A, POGZ, SHANK3, and SYNGAP1. In most individuals with ASD caused by rare gene mutations, the mutations occur in only a single gene.
Problems are usually obvious by the age of 3, but children are often not diagnosed with Asperger syndrome until they are 7 years old. Your child's doctor will look for a group of behaviors.
Autism spectrum disorder (ASD) is typically diagnosed in toddlerhood or early childhood,1 but it is possible for clinicians and parents to miss or overlook the symptoms of high-functioning autism (HFA), in particular, until late childhood, adolescence, or even adulthood.
displays unusual nonverbal communication, such as lack of eye contact, few facial expressions, or awkward body postures and gestures. does not empathize with or seems insensitive to others' feelings and has a hard time “reading” other people or may have difficulty understanding humor.