Amber’s determination to find a miracle for her son Maxwell is detailed in a recent BuzzFeed article. Maxwell and his twin sister, Riley, were born in March 2017.
For the first year of her life, Riley was a playful, healthy little girl while Amber did not see Maxwell making any progress. Amber was especially alarmed when she realized he could not move his hands.
The Diagnosis
On June 18, 2018, Amber met with doctors at the Children’s Hospital Colorado in Denver. Dr. Austin Larson presented the news to Amber that Maxwell’s diagnosis is SLC6A1. The disease is extremely rare. There are only 100 reported cases worldwide.
Dr. Larson told Amber that so far there is no medicine or any type of diet or treatment for the disease. He explained that this is the typical situation with most genetic conditions.
The other doctors who examined Maxwell, along with Dr. Larson, had only one source of reference. They relied upon five pages of research from a 2014 study which was the year that the SLC6A1 gene was discovered.
Amber had the feeling after seeing the reaction by the doctors, that they had never seen anything like this in their many years of practicing medicine. Dr. Larson called it “the rarest of the rare diseases”.
About SLC6A1
Dr. Katherine Helbig a genetic counselor at the Children’s Hospital in Philadelphia spoke at a seminar that was organized by Amber.
Dr. Helbig describes SLC6A1 as a “vacuum cleaner in the brain”. The gene halts message-carrying chemicals by “vacuuming them” when they reach a brain cell.
In Maxwell’s situation, there was a loss of one copy of the SLC6A1 gene. This means a shortage of the protein needed to perform the vacuuming. This, in turn, leads to disorders such as epileptic seizures and symptoms found in autism.
A Race Against Time
It is estimated that Amber and her husband Mark will need to raise about seven million dollars to arrange to test a new genetic treatment for Maxwell.
If they are unable to reach that goal in less than a year, Maxwell would be at the age when epileptic seizures begin. Permanent developmental problems, including those of mild to severe intellectual disability, may occur as a result of these seizures.
The other major challenge is finding researchers who might have an interest in the disease.
Amber, a financial analyst, left her job and began to call scientists and labs. In a space of three months, she had contacted three hundred labs.
Amber’s search led her to gene therapy and a scientist at the Dallas Medical Center named Steven Gray. At about the same time, Dr. Gray and his team had announced the first human experiments of transferring a gene through spinal injection.
The experiment involved five to ten children who had mutations in the GAN gene that can cause brain cells to swell. The GAN gene’s normal function is to identify and eliminate damaged or excess proteins in cells.
Amber recalls that she gave Dr. Gray her “thirty-second financial analyst pitch”. It worked. Dr. Gray agreed to give Maxwell priority and Amber agreed to provide almost seven million dollars needed for the experiment.
About the GAN Experiment
A virus will reproduce by:
- Infecting cells
- Seize the cell’s DNA machinery
- Then reproduce their own genes, and
- Make more viruses
The GAN gene transfer was first tested on mice. A corrected version of the aberrant gene was attached to a noninfectious virus. The virus will travel directly to the brain when it is injected into the spinal cord.
The virus leaves the corrected gene behind in the DNA of the cells that they have infected.
Genetically Altered Mice
Amber wasted no time moving to the next step. She contacted a lab at the Tongji University in Shanghai that was researching SLC6A1.
The lab was working with CRISPR, the exciting new gene modification technology. The lab agreed to develop a mouse with Maxwell’s mutation at a cost to Amber of under $50,000.
By September 2019, CRISPR mice were created at Tongji University with the same genetic mutation carried by Maxwell. According to Amber, this is almost the same as testing Maxwell directly.
The four mice will now be shipped to the U.S. for the next segment of research. While in quarantine they will again be tested to confirm that they carry Maxwell’s SLC6A1 gene mutation.
The scientists will breed them with normal mice with the intent of producing mixed-inheritance offspring to use as controls for future experiments. They will be monitored closely to be certain that they show the same genetics as human SLC6A1 patients.
Gene Therapy Holds Promise
Gene therapy had begun twenty years ago but was sidelined due to the death of an eighteen-year-old volunteer who died as a result of a “harmless” virus in a research experiment.
With more stringent safety measures in place, we can count 2,500 gene therapy clinical trials conducted to date and about 370 at various stages of recruiting. There is every reason to believe that customized treatments are possible for patients like Maxwell.
About Financing
Amber has participated in all aspects of this complex pursuit including fundraising. The family has set up a GoFundMe and raised $600,000 so far. She recently organized the first symposium ever held on SLC6A1. The family held thirty-five fundraisers collecting an additional $400,000. Dr. Larson personally helped Amber with a charity competition raising $75,000.
Amber has set up an advocacy group that she hopes will lead to treatments for children also affected by the SLC6A1 gene.
The CRISPR Mice are Headed for Dr. Gray’s Lab
The next step is to transfer the mice to Dr. Gray’s lab where they will be injected with a virus carrying the corrected SLC6A1 gene. Dr. Gray and his team will be checking to see if their symptoms improve and if their brain cells will accept the gene that has been corrected.
One more safety test will be performed using another SLC6A1 animal model. If successful, it would be time to create an additional gene-correcting virus and conduct a human safety study.
And finally, depending on the results of the human study, it would be time to conduct the experiment on Maxwell and other children. The study would follow the approach used by Dr. Gray in the GAN clinical trial.
If It All Works Out
If the experiment is successful Amber believes it will enable more parents to have their children tested to discover undiagnosed disorders. The Catch 22 is that insurers are reluctant to cover a test for a disease if there is no approved treatment for that disease.
