Haploinsufficiency of the HIRA gene may not always produce severe neurodevelopmental consequences.

A recent report describes neurodevelopmental disorder in a total of three unrelated patients with de novo truncating variants in the HIRA gene. 200 632 subjects who have undergone exome sequencing by the UK Biobank were investigated to identify any variants predicted to cause HIRA haploinsufficiency. Four were found, three with frameshift variants and one with a stop variant. One of these subjects had depression but the others did not have any major neuropsychiatric phenotypes. Variants causing haploinsufficiency of HIRA are very rare but when they do occur it seems that they are not always associated with neurodevelopmental disorder.