A push towards Whole Genome Sequencing and Whole Exome Sequencing in the clinic

In the U.S. and abroad, medical experts are working to incorporate more Whole Genome Sequencing and Whole Exome Sequencing in clinical visits for children with autism spectrum disorder, developmental delays, and intellectual disability. Clinical guidelines on this subject were released July 1 in the U.S. Clinical guidelines can be thought of as recommendations written by doctors to improve healthcare. Whole Genome Sequencing provides the most complete information of all genetic testing methods, by essentially “reading” (sequencing) the entire genome of a person, rather than searching for specific genes. Whole Exome Sequencing is also able to yield much more data than other standard approaches. The distinction between Whole Genome Sequencing and Whole Exome Sequencing, and the comparison to other standard genetic tests will be summarized in future posts.

Although sequencing has been available for some time, the decision to do sequencing is complex, based on financial considerations, preferences of the doctor and the family, and other factors. The new guidelines released July 1 by the American College of Medical Genetics and Genomics argued that the benefits, such as earlier diagnoses, outweigh potential harms.  Costs of sequencing are becoming more affordable and performing sequencing before other tests can save time.

A similar initiative has been launched in France and its upcoming impacts on diagnosing autism and other developmental disorders is being summarized in Spectrum by PMSF’s Scientific Advisory Committee Member, Dr. Thomas Bourgeron, who is a leader on this project. Based on the current response to this initiative, France could collect sequencing data on several thousand families of patients with neurodevelopmental disorders over the next few years.

What does this mean for PMS families?

Sequencing will become more commonly done in the clinic, for both PMS families and for other children with neurodevelopmental disorders. Long-term, this could lead to:

• a large amount of genetic data for scientific studies, including correlating genes (genotype) with symptoms (phenotype) to improve treatments and improve the ability to distinguish mechanisms of neurodevelopmental disorders
• More and faster diagnoses of PMS compared to standard genetic tests, increasing our support network and rationale for research
• More identification of very rare genetic variants in PMS, including SHANK3 variants

U.S. guidelines link: https://www.nature.com/articles/s41436-021-01242-6

France Genomic Medicine Initiative summary link: https://www.spectrumnews.org/features/deep-dive/europes-race-ramp-genetic-tests-autism/