Sequence and copy number analyses of HEXB gene in patients affected by sandhoff disease: Functional characterization of 9 novel sequence variants

Stefania Zampieri, Silvia Cattarossi, Ana Maria Ramirez, Camillo Rosano, Charles Marques Lourenco, Nadia Passon, Isabella Moroni, Graziella Uziel, Antonella Pettinari, Franco Stanzial, Raquel Dodelson de Kremer, Nydia Beatriz Azar, Filiz Hazan, Mirella Filocamo, Bruno Bembi, Andrea Dardis

Research output: Contribution to journalArticle

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Abstract

Sandhoff disease (SD) is a lysosomal disorder caused by mutations in the HEXB gene. To date, 43 mutations of HEXB have been described, including 3 large deletions. Here, we have characterized 14 unrelated SD patients and developed a Multiplex Ligation-dependent Probe Amplification (MLPA) assay to investigate the presence of large HEXB deletions. Overall, we identified 16 alleles, 9 of which were novel, including 4 sequence variation leading to aminoacid changes [c.626C>T (p.T209I), c.634C>A (p.H212N), c.926G>T (p.C309F), c.1451G>A (p.G484E)] 3 intronic mutations (c.1082+5G>A, c.1242+1G>A, c.1169+5G>A), 1 nonsense mutation c.146C>A (p.S49X) and 1 small in-frame deletion c.1260_1265delAGTTGA (p.V421_E422del). Using the new MLPA assay, 2 previously described deletions were identified. In vitro expression studies showed that proteins bearing aminoacid changes p.T209I and p.G484E presented a very low or absent activity, while proteins bearing the p.H212N and p.C309F changes retained a significant residual activity. The detrimental effect of the 3 novel intronic mutations on the HEXB mRNA processing was demonstrated using a minigene assay. Unprecedentedly, minigene studies revealed the presence of a novel alternative spliced HEXB mRNA variant also present in normal cells. In conclusion, we provided new insights into the molecular basis of SD and validated an MLPA assay for detecting large HEXB deletions.

Original languageEnglish
Article numbere41516
JournalPLoS One
Volume7
Issue number7
DOIs
Publication statusPublished - Jul 27 2012

Fingerprint

Sandhoff Disease
Multiplex Polymerase Chain Reaction
Assays
Bearings (structural)
Genes
Amplification
mutation
Mutation
assays
genes
nonsense mutation
Messenger RNA
Nonsense Codon
Proteins
proteins
Alleles
alleles
Processing
cells

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Medicine(all)

Cite this

Sequence and copy number analyses of HEXB gene in patients affected by sandhoff disease : Functional characterization of 9 novel sequence variants. / Zampieri, Stefania; Cattarossi, Silvia; Ramirez, Ana Maria; Rosano, Camillo; Lourenco, Charles Marques; Passon, Nadia; Moroni, Isabella; Uziel, Graziella; Pettinari, Antonella; Stanzial, Franco; de Kremer, Raquel Dodelson; Azar, Nydia Beatriz; Hazan, Filiz; Filocamo, Mirella; Bembi, Bruno; Dardis, Andrea.

In: PLoS One, Vol. 7, No. 7, e41516, 27.07.2012.

Research output: Contribution to journalArticle

Zampieri, S, Cattarossi, S, Ramirez, AM, Rosano, C, Lourenco, CM, Passon, N, Moroni, I, Uziel, G, Pettinari, A, Stanzial, F, de Kremer, RD, Azar, NB, Hazan, F, Filocamo, M, Bembi, B & Dardis, A 2012, 'Sequence and copy number analyses of HEXB gene in patients affected by sandhoff disease: Functional characterization of 9 novel sequence variants', PLoS One, vol. 7, no. 7, e41516. https://doi.org/10.1371/journal.pone.0041516
Zampieri, Stefania ; Cattarossi, Silvia ; Ramirez, Ana Maria ; Rosano, Camillo ; Lourenco, Charles Marques ; Passon, Nadia ; Moroni, Isabella ; Uziel, Graziella ; Pettinari, Antonella ; Stanzial, Franco ; de Kremer, Raquel Dodelson ; Azar, Nydia Beatriz ; Hazan, Filiz ; Filocamo, Mirella ; Bembi, Bruno ; Dardis, Andrea. / Sequence and copy number analyses of HEXB gene in patients affected by sandhoff disease : Functional characterization of 9 novel sequence variants. In: PLoS One. 2012 ; Vol. 7, No. 7.
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AU - Rosano, Camillo

AU - Lourenco, Charles Marques

AU - Passon, Nadia

AU - Moroni, Isabella

AU - Uziel, Graziella

AU - Pettinari, Antonella

AU - Stanzial, Franco

AU - de Kremer, Raquel Dodelson

AU - Azar, Nydia Beatriz

AU - Hazan, Filiz

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AU - Dardis, Andrea

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