Whats New In Genetic Testing

The last few years has demonstrated continued rapid improvements in terms of the technology
enabling genetic testing, the number and types of genetic tests that are clinically and
commercially-available, and the knowledge base used to interpret test results. This section is a
summary update of what is relatively new in genetic testing that Dr. Boles believes may be of
help in children through young adults with neurodevelopmental (autism, ADHD, intellectual
disability, complex epilepsy), functional (cyclic vomiting, migraine, other chronic pain disorders,
dysautonomia, depression, anxiety), and mitochondrial disorders (all of the above, plus more).
For more details regarding what is genetic testing, what are the options and how to decide which
tests are appropriate test for each patient, see Genetic Testing FAQs.

What is new in testing strategies?

Whole exome sequencing

Whole exome sequencing (WES) is replacing panels in most cases

Genetic knowledge is increasing too fast for panels to stay relevant. As soon as a panel is ready
for the market it is outdated. In addition, lower pricing has made WES (sequencing all genes)
very competitive with panel testing. For more information, see the section entitled The different
levels of genetic sequencing.

Whole genome sequencing

Whole genome sequencing (WGS) has arrived in clinical testing

Prices have come down so far that WGS (sequencing all of the DNA) is oftentimes less
expensive than WES plus chromosomal microarray (CMA – detects larger mutation missed by
sequencing). CMA is often ordered in patients with many different conditions, especially with
neurodevelopmental disorders (e.g. autism, epilepsy) or birth defects. For more information on
the types of patients for which CMA testing is recommended, see the section entitled
Chromosomal microarray (CMA). For more information on WGS, see the section entitled The
different levels of genetic sequencing.

Sequencing of the parents and patient

Sequencing of the parents and patient (triome) is more common

Again, this change is driven by the reduction in prices. Triome has some significant advantages,
especially the detection of new sequence variants (mutations absent in both parents). Triome
sequencing is often ordered in patients with many different conditions, especially with
neurodevelopmental disorders (e.g. autism, epilepsy) or birth defects. For more information on
the types of patients for which CMA testing is recommended, see the section entitled Triome
versus singleton testing.

Testing patients with an established diagnosis

Perhaps the diagnosis is incomplete, or just plain wrong? Perhaps the diagnosis is correct, but
standard treatments are inadequate, or even non-existent, and one is looking for potential
treatable genetic factors? In these situations, and more, it can make sense to pursue genetic
testing even it patients with a “diagnosis”. For more information, see the section entitled Should
testing be performed if the patient already has a diagnosis?