Neurodegenerative spliceosomopathies.

Spliceosomal syndromes are a group of disorders caused by pathogenic variants in core spliceosomal RNAs or proteins, leading to defective pre-mRNA splicing and tissue-specific disease vulnerability. Although the spliceosome is ubiquitously expressed, its dysfunction preferentially affects highly splicing-dependent tissues such as the retina and the nervous system. This mini-review focuses on neurodegenerative spliceosomopathies, including spinal muscular atrophy, amyotrophic lateral sclerosis, and retinitis pigmentosa, highlighting how alterations in snRNP biogenesis, spliceosome assembly, and splicing fidelity drive neuronal and photoreceptor degeneration. We discuss shared and distinct molecular mechanisms, unresolved questions on tissue specificity, and emerging therapeutic strategies targeting RNA splicing.