De novo sequence variants, including truncating and splicing variants, in the additional sex‑combs like 3 gene (ASXL3) have been described as the cause of Bainbridge‑Ropers syndrome (BRS).
Bainbridge-Ropers syndrome is a genetic syndrome caused by heterozygous loss-of-function pathogenic variants in ASXL3, which encodes a protein involved in transcriptional regulation.
We identified three novel de novo heterozygous truncating variants distributed across ASXL3, outside the original cluster of ASXL3 mutations previously described for BRS.
Our findings suggest that the expression of the truncated ASXL3 protein, including ASXN and ASXH domains, give rise to BRPS, which is distinct from but overlaps with BOS.
De novo loss of function (LOF) mutations in the ASXL3 gene cause Bainbridge-Ropers syndrome, a severe form of intellectual disability (ID) and developmental delay, but there is evidence that they also occur in healthy individuals.
Therefore we emphasize that BRPS syndrome, caused by ASXL3 loss-of-function variants, is a clinically distinct intellectual disability syndrome with a recognizable phenotype distinguishable from that of Bohring-Opitz syndrome.
De novo truncating mutations in Additional sex combs-like 3 (ASXL3) have been identified in individuals with Bainbridge-Ropers syndrome (BRS), characterized by failure to thrive, global developmental delay, feeding problems, hypotonia, dysmorphic features, profound speech delays and intellectual disability.
Although overlapping features with Bohring-Opitz and Bainbridge-Ropers syndromes exist, features that distinguish the ASXL2-associated condition from ASXL1- and ASXL3-related disorders are macrocephaly, absence of growth retardation, and more variability in the degree of intellectual disabilities.
De novo loss of function (LOF) mutations in the ASXL3 gene cause Bainbridge-Ropers syndrome, a severe form of intellectual disability (ID) and developmental delay, but there is evidence that they also occur in healthy individuals.