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By Carol A. Dutch – Senior Director, Patient Engagement, Lumos Pharma

More than two years ago, a multidisciplinary team of investigators based primarily at Children’s Hospital of Philadelphia (CHOP) set out to advance the scientific and medical community’s understanding of a rare pediatric neurodevelopmental disorder called Creatine Transporter Deficiency (CTD/SLC6A8), first identified in 2001. Their work culminates in a March 2019 article entitled “Early Indicators of Creatine Transporter Deficiency” in the Journal of Pediatrics  (published earlier online in Dec 2018). The study, led by CHOP psychologist Judith Miller, Ph.D., offers useful diagnostic information gathered through interviews and clinical assessments of over 20 CTD individuals and their families. The new study suggests possibilities for earlier diagnosis of CTD and adds to earlier studies that have shed more light on CTD, including a 2013 retrospective study of clinical, biochemical and molecular genetic data of 101 males diagnosed with CTD.

“This project was my first introduction to Creatine Transporter Deficiency,” said the study’s lead author, Dr. Judith Miller, Assistant Professor at the University of Pennsylvania and CHOP’s Center for Autism Research. “I so enjoyed getting to know the amazing families who generously shared their stories with me, about how their children came to be diagnosed. The results were clear– we have a long way to go to improve early identification to make the journey easier for families who are seeking answers. “

Dr. Miller learned that it was often a significant event or symptom that eventually led to a child’s diagnosis with CTD, such as a seizure, or severe delays in walking or talking. But looking back, many families said there were more subtle signs in infancy, like a delayed milestone, or maybe difficulty feeding, and a lot of vomiting. “At the time, these signs didn’t always raise alarms, because they happen to lots of babies,” explains Dr. Miller.  “But, of course now we know they were the first clues of a bigger problem.  The next step to earlier identification is daunting, but important: how to help turn these early signs into information that parents and providers can act on.”

Although Creatine Transporter Deficiency currently does not have a therapeutic option that treats the creatine deficiency by effectively transporting the necessary creatine to neuronal cells, the disease can be easily diagnosed by measuring creatine and related metabolites in blood and/or urine, by proton magnetic resonance spectroscopy (MRS) or through genetic testing that includes sequencing of the SLC6A8 gene.

Hence, Miller and the team’s analysis suggests ways to help healthcare providers become aware of early indicators. When feeding or weight gain issues (significant vomiting or failure to thrive), and motor delays (sitting or crawling),  are coupled with delayed basic milestones, this should be a red flag that can help direct healthcare providers to consider adding a urine screen (that includes creatine deficiency syndromes) or making a genetics referral for their patient.

Rare Disease Day, observed on the last day of February, is one day that globally spotlights the multi-faceted issues involving individuals with rare diseases, including a need for bolstered and continued research. We hope that more researchers are encouraged to spend time and resources on helping the community of rare families and individuals learn more about their conditions that could lead to life-saving and life-altering therapies.


Footnote: The publisher has granted Judith Miller to share the following link to view the article “ Early Indicators of Creatine Transporter Deficiency” until April 12, 2019 to have free access to read or download the article.