What is Schaaf-Yang Syndrome?
Schaaf-Yang Syndrome (or SYS) was first described by Dr Christian Schaaf in 2013. It is caused by a mutation or deletion in the MAGEL2 gene, located on the paternal chromosome 15. This gene is in the same region as the genes affected in Prader-Willi Syndrome.
What are the symptoms of Schaaf-Yang Syndrome?
The symptoms of SYS can vary widely among individuals. Common symptoms include:
Hypotonia (low muscle tone)
Feeding difficulties
Developmental delays
Intellectual disability
Speech and language difficulties
Sleep apnea
Autism Spectrum Disorder
Joint contractures, where joints tighten or shorten causing pain and limit movement, are very common in SYS, particularly in the fingers, knees, and elbows.
What treatments are available for Schaaf-Yang Syndrome?
Currently, there is no cure for SYS. Treatment focuses on managing symptoms and may include Physiotherapy, Speech therapy and Psychiatric treatments. Growth Hormone Therapy, which is commonly used in Prader-Willi Syndrome, has shown benefits in improving muscle strength, height, Body Mass Index (BMI), and social skills in some patients.
Can Schaaf-Yang Syndrome run in families?
Some cases of SYS occur spontaneously and are described as ‘de novo’ mutations, meaning they are new genetic changes. However, SYS can also be inherited from the father, which means there is a possibility that future children could also have Schaaf-Yang Syndrome. It is best to discuss individual cases with a geneticist, and your Paediatrician or GP can provide a referral.
Is Schaaf-Yang Syndrome like Prader Willi Syndrome?
Both conditions involve the MAGEL2 gene in the PWS region of chromosome 15, and have some overlapping symptoms such as hypotonia, difficulty feeding as a baby, sleep apnoea, slow growth and intellectual disability. There are some notable differences between the two. Intense hunger (hyperphagia), a hallmark symptom of PWS, is less common in SYS. In contrast, Autism Spectrum Disorder is significantly more prevalent in SYS than in PWS. Additionally, joint contractures are common in most individuals with SYS, whereas they are not typically associated with PWS.
How is SYS and PWS research related?
Medically, Prader-Willi Syndrome and Schaaf-Yang Syndrome are distinct conditions, but they are genetically linked by the MAGEL2 gene. Research into one condition often benefits the other due to this genetic connection.
Can I fundraise for SYS from the UK?
Absolutely! If you specify that your funds are for SYS research, we will ensure they are allocated accordingly. Projects funded by FPWR UK are thoroughly vetted by the FPWR Scientific Advisory Board in the USA, including research into both PWS and SYS. Rest assured, your contributions will support SYS research if that is your goal.
Where can I find out more about SYS and SYS research?
For more information about SYS and ongoing research, please visit our sister charity’s website at www.fpwr.org/sys-about. You can also download a booklet written by parents for parents, guiding you through the first steps after a SYS diagnosis. Additionally, you can watch a presentation by Dr. Schaaf from 2024 FPWR conferences at https://youtu.be/e3NDi3GP4ks?si=2KC6goTLjbfk3tTu