We describe a 7-year-old male with high functioning autism spectrum disorder (ASD) and maternally-inherited rare missense variant of Synaptotagmin-like protein 4 (<i>SYTL4)</i> gene (Xq22.1; c.835C>T; p.Arg279Cys) and an unknown missense variant of Transmembrane protein 187 (<i>TMEM187</i>) gene (Xq28; c.708G>T; p. Gln236His).