VARIANTYX  POSTS

Fragile X syndrome (FXS) is one of the most common heritable forms of intellectual disability, occurring in approximately 1 in 4,000 males and 1 in 8,000 females. In nearly all cases, the causative mutation is an expansion of the unstable CGG repeat sequence present in the 5’ UTR of the FMR1 gene.

We’ve spoken frequently about variant detection, but variant interpretation is just as important to providing useful genetic testing results. Particularly in the case of whole exome (WES) and whole genome (WGS) analyses which identify thousands of variants. Here we focus on six key variant interpretation strategies that geneticists reviewing a case should have access to.

We’re often asked why whole genome sequencing (WGS) is only performed at 30X coverage while whole exome sequencing (WES) is typically performed at 100X coverage. Isn’t 100X better than 30X? If we’re comparing apples to apples, the answer would logically be yes. But in reality we’re comparing apples to oranges, so the answer is not so intuitively no. Here’s why.

In this week’s post we’re taking a closer look at large (>50bp) structural variants, including copy number variants (CNVs). Previously, we’ve noted how whole genome sequencing (WGS) technology provides unique opportunities for detection of CNVs. But we’re often asked what specific types of structural variants are detected by WGS.

As we prepare for the American Academy of Neurology (AAN) annual meeting in Los Angeles next week, we’ve been reviewing the benefits of clinical whole genome sequencing (WGS) that are helping to diagnose and characterize neurodevelopmental disorders.