Heterogeneous nuclear ribonucleoprotein H2

HNRNPH2 (heterogeneous nuclear ribonucleoprotein H2) is a 449-amino acid protein component of hnRNP complexes involved in pre-mRNA processing (UniProt: P55795). The protein binds poly(RG) sequences and facilitates the processing events necessary to convert pre-mRNAs into mature, translatable mRNA molecules in the cytoplasm.

HNRNPH2 is implicated in intellectual developmental disorder, X-linked, syndromic, Bain type (MRXSB), a condition affecting females and characterized by developmental delay, intellectual disability, hypotonia, seizures, and dysmorphic facial features. Pathogenic variants in HNRNPH2 disrupt normal mRNA processing and contribute to this neurodevelopmental phenotype.

HNRNPH2 is curated in the SFARI database as a Category 2 (strong candidate) autism gene associated with syndromic presentations (SFARI Cat 2). The gene's involvement in autism is most clearly documented in the context of MRXSB, where autism spectrum features co-occur with other developmental and neurological manifestations related to impaired pre-mRNA processing.