Preprint identifies INTS6 loss-of-function variant in Finnish families with mild intellectual disability

A bioRxiv preprint reports the discovery of pathogenic heterozygous loss-of-function variants in INTS6 in a family with six affected members from the Northern Finland Intellectual Disability cohort. INTS6 encodes a conserved component of the phosphatase module of the Integrator complex, a multi-subunit assembly that regulates RNA polymerase II activity and is required for proper transcriptional pause-release at thousands of genes. The discovery was made by screening 1,562 Finnish extended families affected by cognitive impairment — a population isolate strategy that enhances power to detect rare variants.

The Integrator complex has emerged as a recurring theme in neurodevelopmental disorders (NDDs); pathogenic variants in several Integrator subunit genes have been associated with conditions ranging from intellectual disability to epilepsy. This report adds INTS6 to that landscape and begins to characterise the downstream transcriptional consequences of its loss, consistent with broader evidence that disrupted regulation of RNA polymerase II is a point of convergence in NDDs.

The use of an extended Finnish family cohort is methodologically notable: Finland's population history, characterised by successive founder effects and relative isolation, results in enrichment of specific rare variants, facilitating gene discovery that might require much larger samples in outbred populations. Functional follow-up experiments are reported in the preprint. This work is a preprint and has not yet completed peer review.