A loss of function mutation in SLC9A6 (Xq26.3) is responsible for Christianson syndrome in males. We identified a novel splicing mutation (NM_006359.2:c.1141-8C>A) of SLC9A6 in a seven-year-old boy with microcephaly, severe developmental delay, and intractable epilepsy. Functional analysis found multiple aberrant transcripts, none of which maintained the canonical open reading frame. Computer prediction tools, however, failed to detect all of the aberrant transcripts.