FB2025_01 , released February 20, 2025
Human Disease Model Report: RNA repeat diseases
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General Information
Name
RNA repeat diseases
FlyBase ID
FBhh0000059
Disease Ontology Term
Parent Disease
OMIM
Overview

For a number of nucleotide-repeat-expansion diseases, expansions occur within non-coding regions such as UTRs, introns, promoters, or within non-coding genes. The pathological effects of such non-coding expansions appear to be complex and varied. Frequently, non-coding expansions appear to result in repeat-containing transcripts with gain-of-function RNA toxicity. It at least one case, a profound impact on gene expression has been demonstrated (see FBhh0000123). In some cases, non-coding expansions appear to be translated into toxic peptides by repeat-associated non-AUG translation (RAN); some aspects of this phenomenon have been investigated in Drosophila human disease models (see FBhh0000137 and FBhh0000024).

This report includes model systems developed in Drosophila using UAS constructs to drive synthetic constructs of nucleotide repeats of variable composition and length. Synthetic alleles are designated with the prefix "Zzzz" in FlyBase (see the 'Alleles Reported to Model Human Disease' section, below); see also the allele report for CG9650CTG-240.4 (FBal0243220). See the 'Related Diseases' section, below, for a list of RNA repeat diseases characterized in flies.

Although RNA-mediated mechanisms of neurotoxicity may also play a role in diseases associated with polypeptide repeats, expanded CAG repeats within polyglutamine-containing proteins have been shown to be due (at least primarily) to the repeat-containing protein. Results in Drosophila addressing polyglutamine models are described in disease model reports 'polyglutamine diseases, polyQ models' (FBhh0000001), 'polyglutamine diseases' (FBhh0000218), and related disease models listed in these reports.

[updated Sep. 2022 by FlyBase; FBrf0222196]

Disease Summary Information
Disease Summary: RNA repeat diseases
OMIM report
Human gene(s) implicated
Symptoms and phenotype
Genetics

A broad grouping of diseases caused by genes containing nucleotide repeat expansions (most commonly, but not exclusively, nucleotide triplet repeats); expansions may be located in exons, UTRs, or introns.

Cellular phenotype and pathology
Molecular information

RNA-mediated mechanisms of neurotoxicity appear to play a significant role in the pathogenesis of repeat expansion diseases, probably in conjunction with the protein-mediated pathways. Multiple different mechanisms, such as the alteration of gene expression levels and splicing patterns, the generation of small RNAs, the induction of nucleolar stress, the promotion of bi-directional transcription and repeat-associated non-ATG translation of the disease locus, the activation of apoptotic signaling, and the sequestration of cellular components to RNA foci, have been shown for different repeat expansion diseases.

Non-coding expansion disorders typically involve large expansions (from ~100 to 1000 copies), which reside in the non-coding regions of genes, such as promoters, introns or untranslated regions (UTRs). Non-coding expansions typically result in repeat-containing transcripts with gain-of-function RNA toxicity. However, even non-coding expansions can still be translated into toxic peptides by repeat-associated non-ATG translation.

External links
    Disease synonyms
    microsatellite-expansion diseases
    non-coding expansion disorders
    noncoding repeat expansion diseases
    nucleotide repeat expansion diseases
    READs
    repeat-expansion associated diseases
    repeat expansion disorder
    untranslated repeat diseases
    Ortholog Information
    Human gene(s) in FlyBase
      Other mammalian ortholog(s) used
        D. melanogaster Gene Information (0)
        Other Genes Used: Viral, Bacterial, Synthetic (6)
        Summary of Physical Interactions (0 groups)
        Alleles Reported to Model Human Disease (Disease Ontology) (52 alleles)
        Models Based on Experimental Evidence ( 31 )
        Allele
        Disease
        Evidence
        References
        Modifiers Based on Experimental Evidence ( 11 )
        Allele
        Disease
        Interaction
        References
        is ameliorated by AstC-R1JF02656
        is ameliorated by ERRJF02431
        is ameliorated by Eip78CJF02258
        is ameliorated by Ptp69DJF03399
        is ameliorated by ShabJF01823
        is exacerbated by eRF1GD4704
        is ameliorated by tauKO
        is exacerbated by MhcKK102402
        is exacerbated by MhcHMS01471
        is exacerbated by MhcJF02069
        is ameliorated by RanGAPSd
        is ameliorated by CG8173JF01161
        is ameliorated by MybJF02135
        is ameliorated by Top2GL00338
        is ameliorated by Top2JF01300
        is ameliorated by RelGD1199
        is ameliorated by tupHMC03317
        is exacerbated by RhauUAS.Tag:HA
        Models Based on Experimental Evidence ( 1 )
        Modifiers Based on Experimental Evidence ( 1 )
        Models Based on Experimental Evidence ( 4 )
        Modifiers Based on Experimental Evidence ( 4 )
        Allele
        Disease
        Interaction
        References
        is exacerbated by Prosβ61.B.UAS
        is exacerbated by Prosβ21.UAS
        is ameliorated by Hsc70-4UAS.cEa
        is ameliorated by bel5
        is ameliorated by bel6
        is ameliorated by belL4740
        is ameliorated by belcap-1
        is exacerbated by eIF1A645
        is exacerbated by ChATHMC05021
        is exacerbated by PectHMJ30278
        is exacerbated by Sk2HMS03001
        is exacerbated by rasJF01445
        is ameliorated by Drep2ex13
        is ameliorated by bsk1
        is ameliorated by Hsc70-4UAS.cEa
        is exacerbated by HDAC6RNAi.UAS
        is exacerbated by vimark16722
        is exacerbated by Drep2KG02396
        is ameliorated by Drep2d00223
        is exacerbated by mir-277UAS.cTa
        is ameliorated by DENRGD17852
        is ameliorated by DENRKK109336
        is exacerbated by Hrb87FJF01757
        is exacerbated by Hrb98DEJF01249
        Models Based on Experimental Evidence ( 8 )
        Modifiers Based on Experimental Evidence ( 7 )
        Allele
        Disease
        Interaction
        References
        Models Based on Experimental Evidence ( 2 )
        Modifiers Based on Experimental Evidence ( 3 )
        Allele
        Disease
        Interaction
        References
        Models Based on Experimental Evidence ( 5 )
        Modifiers Based on Experimental Evidence ( 3 )
        Alleles Representing Disease-Implicated Variants
        Genetic Tools, Stocks and Reagents
        Sources of Stocks
        Contact lab of origin for a reagent not available from a public stock center.
        Bloomington Stock Center Disease Page
        Related mammalian, viral, bacterial, or synthetic transgenes
        Allele
        Transgene
        Publicly Available Stocks
        Selected Drosophila transgenes
        Allele
        Transgene
        Publicly Available Stocks
        RNAi constructs available
        Allele
        Transgene
        Publicly Available Stocks
        Selected Drosophila classical alleles
        Allele
        Allele class
        Mutagen
        Publicly Available Stocks
        References (74)