RNU4-2 Syndrome or ReNU syndrome is a neurodevelopmental disorder caused by de novo variants in the human gene RNU4-2, which encodes an RNA component of the major spliceosome. It is characterized by hypotonia, global developmental delay, severely impaired intellectual development with poor or absent speech, delayed walking or inability to walk, feeding difficulties with poor overall growth, dysmorphic facial features, and brain anomalies, including ventriculomegaly.[1][2][3][4]

RNU4-2 syndrome
SpecialtyNeurology

RNU4-2 / ReNU syndrome is one of the most prevalent monogenic neurodevelopmental disorders, with variants in RNU4-2 estimated to account for around 0.4% of all neurodevelopmental disorders.[2] The syndrome is an autosomal dominant genetic disorder caused by de novo variants in RNU4-2, a gene on chromosome 12, which encodes the small nuclear RNA (snRNA) U4. U4 is a component of the major spliceosome, a complex of proteins and non-coding RNAs that is necessary for RNA splicing. Most cases of RNU4-2 / ReNU syndrome are explained by a 1-bp insertion (n.64_65insT, NR_003137.2), which is thought to disrupt the interactions of snRNA U4 with the snRNA U6, affecting the stability of the ACAGAGA loop of U6 sRNA which binds 5' splice sites and induces splicing after U4-U6 unwinding.[1][2][3] Disrupted splicing, in particular a change in 5' splice site usage, has been reported in individuals with variants in RNU4-2.[2]

The genetic etiology of RNU4-2 / ReNU syndrome was first described in a preprint in April 2024.[5] It was subsequently published by two research teams independently, both who used data collected by Genomics England. One team, led by the English statistician Daniel Greene working at the Icahn School of Medicine at Mount Sinai, used a Bayesian analysis.[6][3][7] The other team involved a global collaboration led by Yuyang Chen and Nicola Whiffin of the University of Oxford.[2]

Neurodevelopmental disorder with hypotonia, brain anomalies, distinctive facies, and absent language (NEDHAFA) was a suggested name for this syndrome, however, ReNU syndrome (pronounced 'renew') was chosen through a collaboration between researchers and the families of those impacted by variants in RNU4-2. The name symbolises that this diagnosis “renews” hope for a brighter future for all those affected.

References

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  1. ^ a b "ReNU SYNDROME; RENU". OMIM. Retrieved 23 August 2024.
  2. ^ a b c d e Chen, Yuyang; et al. (2024-07-11). "De novo variants in the RNU4-2 snRNA cause a frequent neurodevelopmental syndrome". Nature. doi:10.1038/s41586-024-07773-7. ISSN 1476-4687. PMC 11338827. PMID 38991538.
  3. ^ a b c Greene, Daniel; Thys, Chantal; Berry, Ian R; Jarvis, Joanna; Ortibus, Els; Mumford, Andrew D; Freson, Kathleen; Turro, Ernest (2024-05-31). "Mutations in the U4 snRNA gene RNU4-2 cause one of the most prevalent monogenic neurodevelopmental disorders". Nature Medicine. doi:10.1038/s41591-024-03085-5. PMC 11333284. PMID 38821540.
  4. ^ Schot, Rachel; Ferraro, Federico; Geeven, Geert; Diderich, Karin E M; Barakat, Tahsin Stefan (2024-06-11). "Re-analysis of whole genome sequencing ends a diagnostic odyssey: Case report of an RNU4-2 related neurodevelopmental disorder". Clinical Genetics. doi:10.1111/cge.14574. PMID 38859706.
  5. ^ "De novo variants in the non-coding spliceosomal snRNA gene RNU4-2 are a frequent cause of syndromic neurodevelopmental disorders".
  6. ^ Greene, Daniel; Richardson, Sylvia; Turro, Ernest (2017-07-06). "A Fast Association Test for Identifying Pathogenic Variants Involved in Rare Diseases". American Journal of Human Genetics. 101 (1): 104–114. doi:10.1016/j.ajhg.2017.05.015. PMC 5501869. PMID 28669401.
  7. ^ Yuyang Chen and Daniel Greene (2024-05-31). Genomics England Research Seminar May 2024 - Yuyang Chen and Daniel Greene. YouTube. Retrieved 2024-07-12.

Further reading

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