Upon her birth in February 2008, it was recognized that our daughter Chloe had physical defects or dysmorphisms including heart murmurs, epicanthal eye folds, strabismus (crossed eyes), and low muscle tone. Prenatal and newborn screening did not identify any known disorders. By several weeks of age, global developmental delays became apparent, primarily related to neurological function.
As we started assembling and visiting a variety of doctors and therapists, we were able to identify therapeutic approaches to assist her, but our team was unable to diagnose an underlying condition. At the recommendation of our pediatrician, when Chloe was approximately one year old, we took her to see geneticist Dr. Ken Rosenbaum of Children’s National Medical Center in Washington, DC. Dr. Rosenbaum can be contacted at KRosenba@childrensnational.org.
Dr. Rosenbaum was certain her condition had an underlying genetic origin; however, he did not have an initial diagnosis. He performed tests of her metabolic function and an initial global genetic microarray, both of which were negative. In subsequent years, we performed two additional microarray tests as the testing technology improved, but again had two negative results.
At this point, Dr. Rosenbaum recommended an exome sequencing test, a much higher resolution test for locating or identifying anamolies on the part of the human genome responsible for encoding proteins.
In April 2013, we received the exome test result from diagnostic testing company GeneDx indicating that Chloe’s KAT6A gene was anomalous. This was a unique finding – at the time, the testing company was unable to identify another person anywhere in the world with a KAT6A anomaly and any sort of neurologic or developmental condition. We were thankful for this finding in that it represented the first hint of an underlying cause or diagnosis; however, it was clear that we needed genetic testing to identify KAT6A anomalies in other children to determine if this gene actually plays in important role in physical and neurologic development.
In June 2014, we learned that GeneDx has subsequently identified five additional kids with an anomalous KAT6A gene and congenital and neurodevelopmental symptons in common with Chloe. The geneticists working with these kids are collaborating on a journal paper documenting these clinical findings. In parallel, we are working to identify any other KAT6A test results found by other diagnostic testing centers.