Tom’s parents noticed that he was late with key milestones such as pointing, babbling, and clapping. When he began walking, he was clumsier than other kids and would fall more easily. Tom’s speech was also late to develop, and as a child, he would often be more interested in playing with toys than with other children.

At age four, they noticed a mild hand tremor, and when he started school, the gap between Tom and kids his age became increasingly noticeable. Tom underwent a panel of genetic testing at age ten, which came back normal. By this time, he also had diagnoses of dyspraxia and autism.

At age twelve, following growing concerns about his increasing tremor and muscle twitches, Tom had whole-genome sequencing. Fourteen months later, Tom’s family received the news that both Tom and his younger sister carried a pathogenic DHDDS mutation.