Reverse. With the increasing amount of genetic information available in patients with various neurodevelopmental syndromes, some genes will be observed more than once in patients. In a recent study in the Journal of Medical Genetics, the authors trace back the phenotypes of individuals carrying de novo mutations in PURA. However, there seems to be a wide range of clinical features with a seemingly inverse genotype-phenotype correlation. Continue reading
What is the genomic blind spot?
Beneath the surface. Even though the comprehensiveness of next generation sequencing technologies may suggest that we can capture all the variation in the human genome, there is an entire gray zone of small rearrangements that current technologies are blind to. In a recent publication in the American Journal of Human Genetics, Brand and collaborators now use a novel technology to explore the twilight zone of genomics, the realm of small deletions, duplication, inversions and cryptic complex rearrangements. Continue reading
SETBP1, ZMYND11, and the power of joint exome and CNV analysis
Parallel worlds. There are two fields of genetics for neurodevelopmental disorders that currently produce large amounts of data – the field of copy number variation analysis and the field of exome sequencing. When assigning pathogenicity, information from both genetic technologies are rarely considered jointly. A recent study in Nature Genetics now performs a combined analysis of a large CNV and exome datasets in intellectual disability and autism. Interestingly, this method produces robust results, highlighting novel causative genes. Continue reading
The three challenges of epilepsy precision medicine
Half Moon Bay. I am on my way back from the Precision Medicine Workshop at Half Moon Bay, realizing again that blog posts from scientific meetings are often boring and difficult to write. However, let me try to put together a few thoughts about this meeting. Basically, there are three challenges for epilepsy genetics in the era of precision medicine. Continue reading
Dynamin 1, the synapse, and why epilepsy gene discovery is now officially over
E2 consortium. Infantile Spasms and Lennox-Gastaut Syndrome are two epilepsy syndromes with a strong genetic component. De novo mutations play an important role in genetic epilepsies. However, given the overall mutational noise in the human genome, telling causative genes from innocent bystanders is difficult. In the largest and most comprehensive analysis so far, our E2 consortium just published a joint analysis of 356 patient-parent trios, which were analyzed by exome sequencing. In addition to implicating DNM1, GABBR2, FASN, and RYR3, this publication sends a clear message: the age of gene discovery in epilepsy is over – from now on, genes will find themselves. Let me tell you what I mean by this. Continue reading
The five critical components of a clinical exome team
Fall break. Before our blog will go on a two week hiatus, I wanted to share some ideas with you on the team it takes to get a clinical exome analyzed – my impression is that you need at least different five people to translate genomics into patient care. Continue reading
Publications and thoughts of the week – SUMO, SENP2, and data return from exome studies
This week. Because I was traveling this week, I didn’t manage to put a blog post together for you. However, I wanted to catch up with recent publications in the field. Also, I wanted to point out a recent trend in the field – emerging interest and concern about data return from next-generation sequencing studies. However, let’s start with this week’s publications. Continue reading
The 30-10 rule of clinical exome sequencing
30/10. The impact of whole exome sequencing (WES) on clinical management of patients with neurodevelopmental disorders can increasingly be felt, and overall numbers are emerging, which document the success and impact of this technology on clinical decision making. In 30% of patients with neurodevelopmental disorders, a diagnosis can be obtained through WES, and in 10% of patients, this diagnosis significantly alters patient management. A recent publication in Annals of Neurology investigates whether this concept extends beyond the epileptic encephalopathies and also includes patients with presumed cerebral palsy, cerebellar abnormalities, and hypomyelination. Continue reading
The day I fell in love with Varbank
De novo. Three months ago, I performed a trio exome de novo analysis in a patient-parent trio. From my iPad, in a hotel room in Paris. When I got home a few days later, I was excited to tell my students that the analysis worked. They looked at me slightly confused: “What’s the big deal? We had the analysis complete already a week or so ago.” Last year at this time, I was proud that our lab had established a fully functional de novo analysis pipeline. Suddenly, it’s not a big deal anymore. What happened? Let me tell you about Varbank. Continue reading
Three reasons why exomes are like MRIs – and three reasons why they are not
Exome rounds. How will next-generation sequencing technologies impact on patient care in the future? What role will genetic analyses play in routine health care? Sometimes, the possible role of genetic information is compared to the role of MRI imaging, including the general expertise that is required of clinicians who apply these technologies but are not necessarily dedicated experts in the field. Here are three interesting parallels between exomes and MRI – and three examples how the impact of these technologies differs drastically. Continue reading