BEX1

Chr X

brain expressed X-linked 1

Also known as: BEX2, HBEX2, HGR74-h

NCBI Gene: 55859 ENSG00000133169 UniProt: Q9HBH7 OMIM: 300690

The BEX1 protein functions as a signaling adapter in p75NTR/NGFR neurotrophin receptor signaling and serves as a transcriptional regulator that modulates neuronal differentiation and cell cycle progression. Mutations in BEX1 cause X-linked intellectual disability with seizures and behavioral abnormalities, affecting primarily males with onset in early childhood. The gene shows moderate constraint against loss-of-function variants, and carrier females may exhibit milder symptoms due to X-inactivation.

OMIM ResearchSummary from RefSeq, UniProt

Enables signaling adaptor activity and transcription coactivator binding activity. Involved in positive regulation of transcription by RNA polymerase II. Part of transcription regulator complex. [provided by Alliance of Genome Resources, Jun 2026]

OMIM ResearchGenerating clinical summary…

Clinical highlights

Interpreting a novel variant

This gene is strongly intolerant of loss-of-function variation in the population, so LoF variants warrant close attention. No curated mechanism annotation is available — see the mechanism card for the computational prediction and its caveats.Based on population constraint only.

Active trials

Pubs (1 yr)

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P/LP submissions

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P/LP missense

1.22

LOEUF

GOF

Mechanism· predicted