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Two novel truncating variants of the AAAS gene causative of the triple A syndrome

  • V. Vezzoli
  • P. Duminuco
  • G. Pogliaghi
  • M. Saccone
  • B. Cangiano
  • M. C. Rosatelli
  • A. Meloni
  • L. Persani
  • M. BonomiEmail author
Original Article

Abstract

Purpose

The triple A syndrome (AAAS) is an inherited condition associated with mutations in the AAAS gene, which encodes a protein of 546 amino acids known as ALADIN (alacrima achalasia adrenal insufficiency neurologic disorder) whose function is not well understood. This protein belongs to the WD-repeat family of regulatory proteins and is located in the nuclear pore complexes. Only a few cohorts of AAAS patients have been reported and fully characterized. Thus, the objective of the present study was to report on a mini cohort of Italian AAAS patients and to get insights on their predisposing genetic defects.

Methods

Genetic analysis of AAAS gene in triple A syndrome patient and molecular and functional characterization of the novel identified allelic variants.

Results

Here we describe three newly diagnosed cases of AAAS, in whom genetic analysis allowed us to identify two novel allelic variants in the AAAS gene: the frameshift substitution c.765 dupT (p.Gly256Trp fsX67) in exon 8 and the splice site mutation in intron 11(c.997–2 A > G, IVS11-2A > G). Both variants result in a truncated non-functional protein, as we demonstrate by transcript analysis and expression studies.

Conclusions

Our findings establish a pathogenic role for both new variants. Moreover, our data highlight the essential role of the C-terminal domain of the protein for its correct targeting and function and underline the importance of sequencing splice sites surrounding the intron–exon junctions to ensure accurate molecular diagnosis and correct genetic counseling in AAAS patients.

Keywords

ALADIN protein Triple A syndrome Congenital hypoadrenalism Human splicing finder mRNA splicing Allgrove syndrome 

Notes

Acknowledgements

This work was supported by funds from IRCCS Istituto Auxologico Italiano (Ricerca Corrente Funds: 05C822). Authors are in debt to Professor Sungjoo Kim Yoon (Catholic University of Korea) for providing them plasmid pEGFP-C1.

Compliance with ethical standards:

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

The study, accomplishing the Declaration of Helsinki, was approved by Ethic Committee of the Istituto Auxologico Italiano.

Informed consent

All patients or their tutors gave a written informed consent.

References

  1. 1.
    Cho AR, Yang KJ, Bae Y et al (2009) Tissue-specific expression and subcellular localization of ALADIN, the absence of which causes human triple A syndrome. Exp Mol Med 41:381–386.  https://doi.org/10.3858/emm.2009.41.6.043 CrossRefPubMedPubMedCentralGoogle Scholar
  2. 2.
    Allgrove J, Clayden GS, Grant DB, Macaulay JC (1978) Familial glucocorticoid deficiency with achalasia of the cardia and deficient tear production. Lancet (London, England) 1:1284–1286CrossRefGoogle Scholar
  3. 3.
    Huebner A, Elias LL, Clark AJ (1999) ACTH resistance syndromes. J Pediatr Endocrinol Metab 12(Suppl 1):277–293PubMedGoogle Scholar
  4. 4.
    Tullio-Pelet A, Salomon R, Hadj-Rabia S et al (2000) Mutant WD-repeat protein in triple-A syndrome. Nat Genet 26:332–335.  https://doi.org/10.1038/81642 CrossRefPubMedGoogle Scholar
  5. 5.
    Weber A, Wienker TF, Jung M et al (1996) Linkage of the gene for the triple A syndrome to chromosome 12q13 near the type II keratin gene cluster. Hum Mol Genet 5:2061–2066.  https://doi.org/10.1093/hmg/5.12.2061 CrossRefPubMedGoogle Scholar
  6. 6.
    Papageorgiou L, Mimidis K, Katsani KR, Fakis G (2013) The genetic basis of triple A (Allgrove) syndrome in a Greek family. Gene 512:505–509.  https://doi.org/10.1016/j.gene.2012.10.008 CrossRefPubMedGoogle Scholar
  7. 7.
    Huebner A, Kaindl AM, Knobeloch KP et al (2004) The triple A syndrome is due to mutations in ALADIN, a novel member of the nuclear pore complex. Endocr Res 30:891–899CrossRefGoogle Scholar
  8. 8.
    Vallet A-E, Verschueren A, Petiot P et al (2012) Neurological features in adult Triple-A (Allgrove) syndrome. J Neurol 259:39–46.  https://doi.org/10.1007/s00415-011-6115-9 CrossRefPubMedGoogle Scholar
  9. 9.
    Roucher-Boulez F, Brac de la Perriere A, Jacquez A et al (2018) Triple-A syndrome: a wide spectrum of adrenal dysfunction. Eur J Endocrinol 178:199–207.  https://doi.org/10.1530/EJE-17-0642 CrossRefPubMedGoogle Scholar
  10. 10.
    Handschug K, Sperling S, Yoon SJ et al (2001) Triple A syndrome is caused by mutations in AAAS, a new WD-repeat protein gene. Hum Mol Genet 10:283–290.  https://doi.org/10.1093/hmg/10.3.283 CrossRefPubMedGoogle Scholar
  11. 11.
    Cronshaw JM, Krutchinsky AN, Zhang W et al (2002) Proteomic analysis of the mammalian nuclear pore complex. J Cell Biol 158:915–927.  https://doi.org/10.1083/jcb.200206106 CrossRefPubMedPubMedCentralGoogle Scholar
  12. 12.
    Hirano M, Furiya Y, Asai H et al (2006) ALADINI482S causes selective failure of nuclear protein import and hypersensitivity to oxidative stress in triple A syndrome. Proc Natl Acad Sci USA 103:2298–2303.  https://doi.org/10.1073/pnas.0505598103 CrossRefPubMedGoogle Scholar
  13. 13.
    Storr HL, Kind B, Parfitt DA et al (2009) Deficiency of ferritin heavy-chain nuclear import in triple a syndrome implies nuclear oxidative damage as the primary disease mechanism. Mol Endocrinol 23:2086–2094.  https://doi.org/10.1210/me.2009-0056 CrossRefPubMedPubMedCentralGoogle Scholar
  14. 14.
    Prasad R, Metherell LA, Clark AJ, Storr HL (2013) Deficiency of ALADIN impairs redox homeostasis in human adrenal cells and inhibits steroidogenesis. Endocrinology 154:3209–3218.  https://doi.org/10.1210/en.2013-1241 CrossRefPubMedPubMedCentralGoogle Scholar
  15. 15.
    Jühlen R, Idkowiak J, Taylor AE et al (2015) Role of ALADIN in human adrenocortical cells for oxidative stress response and steroidogenesis. PLoS ONE 10:e0124582.  https://doi.org/10.1371/journal.pone.0124582 CrossRefPubMedPubMedCentralGoogle Scholar
  16. 16.
    Carvalhal S, Ribeiro SA, Arocena M et al (2015) The nucleoporin ALADIN regulates Aurora A localization to ensure robust mitotic spindle formation. Mol Biol Cell 26:3424–3438.  https://doi.org/10.1091/mbc.E15-02-0113 CrossRefPubMedPubMedCentralGoogle Scholar
  17. 17.
    Sandrini F, Farmakidis C, Kirschner LS et al (2001) Spectrum of mutations of the AAAS gene in Allgrove syndrome: lack of mutations in six kindreds with isolated resistance to corticotropin. J Clin Endocrinol Metab 86:5433–5437.  https://doi.org/10.1210/jcem.86.11.8037 CrossRefPubMedGoogle Scholar
  18. 18.
    Goizet C, Catargi B, Tison F et al (2002) Progressive bulbospinal amyotrophy in Triple A syndrome with AAAS gene mutation. Neurology 58:962–965.  https://doi.org/10.1212/WNL.58.6.962 CrossRefPubMedGoogle Scholar
  19. 19.
    Wang W, Malcolm BA (1999) Two-stage PCR protocol allowing introduction of multiple mutations, deletions and insertions using QuikChange(TM) Site-Directed Mutagenesis. Biotechniques 26:680–682.  https://doi.org/10.2144/99264st03 CrossRefPubMedGoogle Scholar
  20. 20.
    Krumbholz M, Koehler K, Huebner A (2006) Cellular localization of 17 natural mutant variants of ALADIN protein in triple A syndrome - shedding light on an unexpected splice mutation. Biochem Cell Biol 84:243–249.  https://doi.org/10.1139/o05-198 CrossRefPubMedGoogle Scholar
  21. 21.
    Desmet F-O, Hamroun D, Lalande M et al (2009) Human Splicing Finder: an online bioinformatics tool to predict splicing signals. Nucleic Acids Res 37:e67.  https://doi.org/10.1093/nar/gkp215 CrossRefPubMedPubMedCentralGoogle Scholar
  22. 22.
    Smith TF, Gaitatzes C, Saxena K, Neer EJ (1999) The WD repeat: a common architecture for diverse functions. Trends Biochem Sci 24:181–185CrossRefGoogle Scholar
  23. 23.
    Persic M, Prpić I, Huebner A, Severinski S (2001) Achalasia, alacrima, adrenal insufficiency, and autonomic dysfunction: double A, triple A, or quaternary A syndrome? J Pediatr Gastroenterol Nutr 33:503–504CrossRefGoogle Scholar
  24. 24.
    Schmittmann-Ohters K, Huebner A, Richter-Unruh A, Hauffa BP (2001) Clinical and novel molecular findings in a 6.8-year-old Turkish boy with triple A syndrome. Horm Res 56:67–72.  https://doi.org/10.1159/000048093 CrossRefPubMedGoogle Scholar
  25. 25.
    Houlden H, Smith S, De Carvalho M et al (2002) Clinical and genetic characterization of families with triple A (Allgrove) syndrome. Brain 125:2681–2690.  https://doi.org/10.1093/brain/awf270 CrossRefPubMedGoogle Scholar
  26. 26.
    Gazarian M, Cowell CT, Bonney M, Grigor WG (1995) The “4A” syndrome: adrenocortical insufficiency associated with achalasia, alacrima, autonomic and other neurological abnormalities. Eur J Pediatr 154:18–23.  https://doi.org/10.1007/bf01972967 CrossRefPubMedGoogle Scholar
  27. 27.
    Patt H, Koehler K, Lodha S et al (2017) Phenotype-genotype spectrum of AAA syndrome from Western India and systematic review of literature. Endocr Connect 6:901–913.  https://doi.org/10.1530/EC-17-0255 CrossRefPubMedPubMedCentralGoogle Scholar
  28. 28.
    Clark AJL, Weber A (1998) Adrenocorticotropin Insensitivity Syndromes. Endocr Rev 19:828–843.  https://doi.org/10.1210/edrv.19.6.0351 CrossRefPubMedGoogle Scholar
  29. 29.
    Collares CVA, Antunes-Rodrigues J, Moreira AC et al (2008) Heterogeneity in the molecular basis of ACTH resistance syndrome. Eur J Endocrinol 159:61–68.  https://doi.org/10.1530/EJE-08-0079 CrossRefPubMedGoogle Scholar
  30. 30.
    Maquat LE (2004) Nonsense-mediated mRNA decay: splicing, translation and mRNP dynamics. Nat Rev Mol Cell Biol 5:89–99.  https://doi.org/10.1038/nrm1310 CrossRefPubMedGoogle Scholar
  31. 31.
    Cronshaw JM, Matunis MJ (2003) The nuclear pore complex protein ALADIN is mislocalized in triple A syndrome. Proc Natl Acad Sci USA 100:5823–5827.  https://doi.org/10.1073/pnas.1031047100 CrossRefPubMedGoogle Scholar
  32. 32.
    Dumic M, Barišic N, Kusec V et al (2012) Long-term clinical follow-up and molecular genetic findings in eight patients with triple A syndrome. Eur J Pediatr 171:1453–1459.  https://doi.org/10.1007/s00431-012-1745-1 CrossRefPubMedGoogle Scholar
  33. 33.
    Prpic I, Huebner A, Persic M et al (2003) Triple A syndrome: genotype-phenotype assessment. Clin Genet 63:415–417CrossRefGoogle Scholar

Copyright information

© Italian Society of Endocrinology (SIE) 2020

Authors and Affiliations

  1. 1.Dipartimento di Scienze Cliniche e di Comunità, Division of Endocrine and Metabolic Diseases and Lab. of Endocrine and Metabolic Research, Dipartimento di Medicina Endocrino-MetabolicaUniversità degli studi di Milano, IRCCS Istituto Auxologico ItalianoMilanoItaly
  2. 2.Pediatric Hospital “Microcitemico” Antonio Cao, Azienda Ospedaliera Brotzu, University of CagliariCagliaryItaly
  3. 3.Department of Clinical Sciences and Community HealthUniversity of MilanMilanItaly

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