Ring Chromosome Overview / Genetic Studies of r(20) syndrome - PROF NANCY B SPINNER

Ring Chromosome Overview / Genetic Studies of r(20) syndrome The second in a series of video presentations from our recent r(20) Families Conference which describes what we know about this rare disease from a genetic perspective and summarises some of the findings from Prof Spinner's research team at CHOP in the USA. Ring Chromosome 20 Syndrome was first diagnosed in 1972, associated with epilepsy, intellectual disability with non-dysmorphic features. Understand the definition of a Chromosome Disorder, what is a ring chromosome - how or why it occurs and also know that all rings are not formed the same. You will hear from Prof Spinner (Professor of Paediatric Pathology) why, due to so many changes in genetic diagnostics and the newer advances made, it has actually become harder to diagnose r(20) syndrome. How do we diagnose epilepsy today from a genetic perspective? Know that there are hundreds of genes associated with epilepsy and new genes are being discovered everyday, making it very hard to diagnose causes of epilepsy generally. So how do you diagnose r(20) syndrome? Chromosome analysis is required and this technique is not typically used for diagnosing epilepsy today. The neurologist needs to order chromosome analysis separately when he/she suspects a patient may have r(20) syndrome (from recognition of the signs and symptoms). Chromosomal microarray (SNP array) - the most commonly used technique used for when a child is suspected to have a chromosomal disorder or is tested for genetic cause for their epilepsy - will not detect a ring chromosome (in mosaic patients). Learn about the differences between mosaic and non-mosaic rings - two thirds of r(20) patients are mosaics. In mosaic patients it has been observed that there are no deletions in the ring chromosome, whereas in non-mosaic patients there is always a deletion of genetic material. Importantly therefore r(20) syndrome is perceived to be under diagnosed. This video represents new and important up-to-date information regards recognising Ring Chromosome 20 Syndrome through its unique features, from the viewpoint of the geneticist. An important educational short video for any epilepsy professional. We strongly encourage sharing of this video. We welcome any feedback that you have so please do get in contact.