Innovative Genetics; Solving Autism

Sarah Grice

What is Autism?

Autism Spectrum Disorders, commonly referred to as "Autism" is a developmental disorder that affects social interaction and language. It is known a "spectrum" disorder because it presents with a wide range in the degree of impairment, and appearance of symptoms. Autism is known to be a multifactorial disorder that involves not only genes, but also environmental factors. In the past, specific environmental factors such as vaccines have been erroneously named as causes of this disorder. Recently, however, ground breaking studies have identified "several dozen 'high-confidence' autism genes that show spontaneous, harmful mutations" (Ronemus, 2014). While these studies do not provide a complete explanation for the disorder, they give the healthcare community a strong foundation in which to continue further research.

Genetics and Autism

While the exact cause of Autism is still not known, twin concordance studies suggest that there is a very strong genetic link. The concordance rate in identical twins, sharing 100% of their genetic information, is 77%, while the concordance rate in fraternal twins, sharing only 50% of their genetic information is only 31% (Chung, 2014).

It is now known that Autism can also be caused by genetic changes that are not inherited directly from generation to generation within a family. In fact, one study relied on data from the Simons Simplex Collection, which is "a database of families that have one child with autism and unaffected parents and siblings" (Wright, 2014). This data is specifically designed to identify these spontaneous ("de novo") mutations. This research found an astonishing 391 killer mutations in 353 genes in children with autism, and "by looking at the rates of these mutations in unaffected siblings, they estimate that roughly 40 percent of the de novo loss-of-function mutations contributed to autism diagnoses" (Wright, 2014).

Some of the non-genetic causes linked with autism include:
  • Advanced paternal age
  • Teratogens (such as Valproic acid) during pregnancy
  • Infectious Agents

Impact on the Future of Medicine & Nursing

Most importantly, this research provides a solid foundation for continued research on Autism. Now that researchers have identified genes and alleles that are involved in causing autism, they can begin to use a bottom up approach to understand the disorder. That is starting with the molecules, and working up to the patient as a whole. Having identified these genes also allows for the exciting possibility of developing targeted drug therapy.

Patients and their families suffering from autism rely not only on this ground breaking research, but also their nurses to help educate them in this matter. Parent's of affected children often have many questions - especially related to the causes, treatments, and outcomes associated with Autism. These are all questions that we can begin to answer. Yes, autism has been linked to genetic mutations, many of which are spontaneous and not inherited. Yes, there are also environmental risk factors such as paternal age and teratogens. No, vaccines and GMO's will NOT cause Autism. Current treatments involve behavioral therapy, educational strategies, and some medications to deal with symptoms such as irritability. New targeted drugs may developed in the not-so-distant future as the result of ground breaking genetic research. Early diagnosis can improve patient outcome, and tests such as those that identify infant eye contact and tracking can assist in this process.

Summary

Autism as a disorder has a vast array of symptoms and affects each individual with different severity. This discrepancy can be attributed to the multifactorial nature of the disorder. In addition to some environmental causes, twin concordance studies have identified a strong genetic link. More in depth research has recently found between 200-400 genes can be directly linked to autism. This research offers an exciting new starting point for developing not only a better understanding of the disorder, but also possible targeted drug therapies. As research continues to reveal a better understanding of this disorder, nurses will play a crucial role in educating patients on the information, resources, and tools available.

References

Chung, W. (2014, March). Wendy Chung: Autism - what we know (and what we don't...) [Video File]. Retrieved from http://www.ted.com/talks /wendy_chung_autism_what_we_know_and_what_we_don_t_know_yet#t-813964

Ronemus, M. (2014). Future of autism genetics should learn from its past. Retrieved December 11, 2014, from http://sfari.org/news-and-opinion/viewpoint/2014/future-of-autism-genetics-should-learn-from-its-past


Wright, J. (2014). Massive sequencing studies reveal key autism genes. Retrieved November 20, 2014, from http://sfari.org/news-and-opinion/news/2014/massive-sequencing-studies-reveal-key-autism-genes