The study compared 7 males with inherited loss of function mutations in the ZDHHC9 gene (Age in years: mean=29.13, SE=4.86, Range=13.83-41.83) to 7 males individually matched in age +/- 2 years (Age in years: mean=27.23, SE=5.31, Range=10.17-42.5). Comparison subjects had no history of neurological illness or cognitive impairment. Statistical analysis indicated no significant difference in age between the groups (Welch-corrected t-test: t(11.91)=-0.265, p=0.796).

For detailed description of clinical and cognitive characteristics of the ZDHHC9 group see Baker et al. 2015. In summary, all individuals with a ZDHHC9 mutation had mild to moderate intellectual disability (full-scale IQ: mean=64.86, SE=2.32, Range=57-73). 5 individuals had a history of epilepsy, with seizure characteristics and EEG features similar to the Rolandic epilepsy spectrum. At the time of MRI acquisition, 1 participant reported seizures within the previous 3 months, and 3 currently received anti-epileptic medication (carbemazapine n=1, carbemazapine and lamotrigine n=1, phenytoin n=1). ). Vineland scores \cite{Sparrow_2005} indicated stronger receptive language abilities compared to expressive and written language abilities in the ZDHHC9 group. The Verbal Motor Production Assessment for Children (VMPAC) \cite{Hayden_1999}. indicated significant oromotor difficulties in the ZDHHC9 group, including deficits in oral control, sequencing, voice characteristics, and connected speech. Inhibitory control was also reduced in the ZDHHC9 group on a visual attention task. These specific features differentiated with ZDHHC9 group from age and IQ matched controls \cite{Baker_2015}.