Recently, autosomal recessive mutations in the human tweek ortholog gene KIAA1109 were found to cause Alkuraya-Kucinskas syndrome (MIM #617822) characterized by global developmental delay and severe neurological abnormalities (Alazami et al., 2015; Gueneau et al., 2018). Here, BLTP1 is linked to Alkuraya-Kucinskas syndrome.