In 2004, separate case-studies were published by Dr. John Christodoulou and Dr. Vera Kalsceuer on mutations in CDKL5 producing severe neurodevelopmental disorder and mental retardation. These papers concluded that mutations in the CDKL5 gene gave rise to a phenotype overlapping with that of the MECP2 which causes Rett Syndrome. This may have led many patients in the past to be misdiagnosed, however, because of these studies we now know that CDKL5 should be distinguished as a distinct disorder.
Raising public awareness of CDKL5 disorder is vital for attracting research interest and funding opportunities. Although the research is in its infancy the disorder has already raised international interest in Canada, USA, Italy and elsewhere.
To learn about the discovery of the CDKL5 gene and the distinction of CDKL5 disorder from Rett syndrome read Dr. Christodoulou's document below - "Discovery of CDKL5 gene and CDKL5 disorder"
Do you know what Glyn’s legacy is all about? Read his story written by his mother L. Boltwood. His gift led to the discovery of CDKL5 disorder,
unfortunately, he passed on June 17, 1997. Glyn’s story is below - "CDKL5 Awareness Day honors Glyn's Legacy”
Peace Bridge - The lights will come on at dusk and remain on until 1:00 AM.
CN Tower - Illumination will begin at sunset. A standard light show will run for 8 minutes at the top of every hour as it does every night.
Niagara Falls - Both the Canadian and American Falls will be illuminated at 10:00 p.m. for fifteen (15) minute duration.
My interest in CDKL5 grew from our longstanding research interest in Rett syndrome. Our group first established MECP2 mutation testing in Australia shortly after its association with Rett syndrome was discovered. In collaboration with research teams in Perth, Western Australia and Cardiff, Wales, we went on to study the relationships between mutations in the MECP2 gene and their clinical consequences in groups of patients. With Patrick Tam, a brilliant mouse developmental biologist at the Children’s Medical Research Institute in Sydney, we went on to “build” several Mecp2 knockout mice, which have allowed us to do a range of studies aimed at understanding the biology of the Mecp2 protein. It is only by having a very deep understanding of these biological processes that we will be able to develop specific treatments.
During the course of our MECP2 genetic studies we encountered a number of families where no MECP2 mutations could be identified. One of these families in Australia is well known to the CDKL5 group. Using a combination of sophisticated genetic techniques in this sentinel family, we were able to narrow down the search for the gene to a relatively “small” segment of the X chromosome. Further studies, in collaboration with genetic researchers in Adelaide and Cardiff, led to our discovery of mistakes (mutations) in the CDKL5 gene in this Australian family and in a Welsh family, and our realization that some girls with Rett syndrome or a Rett-like clinical appearance could have mutations of the CDKL5 gene. Others have subsequently confirmed our findings and have extended their studies to demonstrate that CDKL5 mutations can also be found in people who do not resemble Rett syndrome very much at all.
More recent studies suggest that the clinical picture caused by CDKL5 mutations is quite distinct from Rett syndrome, which warrants classification as a separate syndrome, which we dubbed the CDKL5 disorder. The clinical depiction of the CDKL5 disorder includes a severe seizure disorder called epileptic encephalopathy (with an onset of severe seizures in the first six months of life, and in fact for many within the first three months of life), severe developmental delay from early infancy, and the presence of hand stereotypies. We have also noted that many affected individuals share subtle facial similarities.
Glyn’s legacy has been to lead to a whole new area of research focused on understanding the biology of how CDKL5 affects brain function, with the ultimate goal being to identify specific therapies for the CDKL5 disorder.
Professor John Christodoulou AM
NSW Centre for Rett Syndrome Research
Children’s Hospital at Westmead
"Are you sitting down?" These are not words a parent wants to hear in connection to their child but this time they heralded some extraordinary news: "We've found your gene."
This news ended a 23-year long search that began when Glyn, our third beautiful child had an Infantile Spasm at only two days old. Dismissed as colic because Glyn showed no other symptoms, we tried to ignore the rapid increase in these spasms and had repeated reassurances by his pediatrician until his first hospital admission at 9 weeks of age when he had a tonic/clonic seizure. Our son Glyn struggled for 16 years through daily seizures and never ending drugs that wreaked havoc on his little body leading him to develop respiratory, intestinal and skeletal problems so severe they overtook the focus of stopping the seizures that were now described as Lennox Gastaut like.
We thought we'd said our last goodbye to Glyn so many times over those years but he showed us time and again he wasn't ready to leave by fighting on and pulling through the many crises that threatened him.
Our identical twin girls were born when Glyn was two years old. Perfect, pink and oh, so tiny. We were thrilled to have some joy back in our lives. But when nine-week old Asha had a spasm while nursing, I knew what it was in an instant and a shockwave ran through me.
The next few years were a repeat of what we had been through with Glyn but with added fear. Because Asha and Bree were identical twins, was Bree certain to develop seizures as well? We scrutinized her every movement for years, until that fear faded into the background of a never ending cycle of hospital admissions, therapy sessions, seizure charts, drugs and special diets for Glyn and Asha.
Bree didn't develop seizures but she didn't come through it unscathed. Her development was ‘unique,' a mix of repetitive odd behaviors, major melt downs, sensitivities, delayed speech and social avoidance. It took 9 years for someone to finally diagnose her with autism. With the diagnosis came huge relief. For years, I had been told that Bree's behavior was related to the stressful home environment that comes with caring for medically fragile children. It was a relief to know there was a medical cause.
What happened to my babies? I needed to know. I sought out research studies and doctors linked to any one of the many issues my children faced. Among these was a chance meeting. I overheard a doctor mention Rett Syndrome as he passed by Glyn's hospital room with a group of medical students. I quickly introduced myself to the geneticist, Prof. John Christodoulou.
Though nothing came of that first meeting, it later proved to be a very important piece of our puzzle. I volunteered my children to be part of two separate studies that years later had a huge bearing on the discovery of ‘our gene'. One of the studies was on siblings with epilepsy, the other on siblings with autism. Blood was drawn from all of my children so their DNA could be compared with others who had seizure disorders. This DNA was stored for future studies.
A doctor involved in the autism study had one quick look at Asha who was sitting in her wheelchair in her usual pose of one leg folded up over the other and her hands in her mouth and said, "She has Rett Syndrome." I told her how this had been disputed time after time but she was adamant saying, "I worked with Andreas Rett and I have seen enough girls with RTT to recognize it."
That statement led me back to Prof. John Christodoulou who was very involved in Rett Syndrome research and also linked me into the large Rett Community. It was the first time I felt as though I belonged anywhere. Meeting with other families and joining an online support group for families who had a child with Rett Syndrome and knew exactly what I was talking about when describing Asha gave me the strength to carry on supporting my children. However, there was a niggling doubt in my mind about our Rett connection. Nobody else spoke of Infantile Spasms or siblings with similar problems, but there were a few who mentioned having another child with autism.
In 1999 when the RTT gene Mecp2 was discovered and Asha tested negative I felt as though once again we were on our own. Mecp2 was found in 80% of those with Rett Syndrome and now researchers continued to search for the other gene or genes responsible for the 20% who tested negative.
When Glyn passed away in 1997, I was left wondering what his life had been all about. What reason was there for his suffering? I couldn't believe he'd been here for no reason. And then, in 2004 Prof. John Christodoulou led an Australian research team that studied my children's DNA and found abnormalities they had in common with a gene called STK9 (later to be known as CDKL5).
At the same time, a German research team had found CDKL5 to be the second gene responsible for Infantile Spasms and had discussed the link between this gene and atypical RTT. These two groups independently discovered CDKL5 to be the second gene responsible for RTT and their research papers were published simultaneously in the same issue of the prestigious journal, The American Journal of Human Genetics 2004.
Glyn's stored DNA was his gift to all those who have since been given a diagnosis of what is now known as a CDKL5 related disorder. Without it, the many families around the globe whose child has a CDKL5 mutation might still be searching for a cause as to why their beautiful baby has such a devastating disorder. They would be where I was all those years ago, not knowing, not belonging and on an eternal mission to find an answer.
Glyn gave us part of himself that enabled the discovery of CDKL5 which will now lead us to find treatments and a cure for children suffering from a CDKL5 related disorder.
I was told recently by another mother of a child who has a CDKL5 disorder that I am amazing for what I have done and still do for my children. I replied that I do what has to be done, but I should have expanded on that. I should have said: "You will too because your child will repay you a hundredfold with smiles so pure and full of love your heart will melt. It may not be often but you will never take it for granted.
You will learn that every moment you spend with your child is precious and every small achievement they make will be celebrated as though they have won gold at the Olympics. You will discover a strength within yourself that you never knew existed when you think you can't possibly take anymore.
You will gather friends who share a bond that only those who have a ‘special child' can share. Through their friendship you will be given support and encouragement you know is genuine because they really do understand. You will often ask ‘why me?' and most likely will never find an answer until one day someone will tell you that you are amazing for what you do and you will say to them they would do it too if they had a child as wonderful as yours. "