Spontaneous recurrent mutations and a complex rearrangement in the MECP2 gene in the light of current models of mutagenesis.
Mutat Res
; 734(1-2): 69-72, 2012 Jun 01.
Article
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| MEDLINE
| ID: mdl-22525432
ABSTRACT
Mutations in the methyl-CpG-binding protein 2 (MECP2) gene are associated with Rett syndrome (RTT). The MECP2 gene has some unique characteristics (1) it is mainly affected by de novo mutations, due to recurrent independent mutational events in a defined "hot spot" regions or positions; (2) complex mutational events along a single allele are frequently found in this gene; (3) most mutations arise on paternal X chromosome. The recurrent point mutations involve mainly CpG dinucleotides, where C>T transitions are explained by methylation-mediated deamination. The complex mutational events might be explained by the genomic architecture of the region involving the MECP2 gene. The finding that most spontaneous mutations arise on paternal X-chromosome supports the higher contribution of replication-mediated mechanism of mutagenesis. We present 9 types of mutations in the MECP2 gene, detected in a group of 22 Bulgarian and 6 Romanian classical RTT patients. Thirteen patients were clarified on molecular level (46.4%). The point mutations in our sample account for 61.5%. One intraexonic deletion was detected in the present study (7.7%). One novel insertion c.321_322insGAAG, p.(Lys107_Leu108insGluAlafs2*) was found (7.7%). Large deletions and complex mutations account for 23%. A novel complex mutational event c.[584_624del41insTT; 638delTinsCA] was detected in a Romanian patient. We discuss different types of the MECP2 mutations detected in our sample in the light of the possible mechanisms of mutagenesis. Complex gene rearrangements involving a combination of deletions and insertions have always been most difficult to detect, to specify precisely and hence to explain in terms of their underlying mutational mechanisms.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Síndrome de Rett
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Proteína 2 de Unión a Metil-CpG
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Mutación
Tipo de estudio:
Prognostic_studies
Límite:
Female
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Humans
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Infant
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Newborn
Idioma:
En
Año:
2012
Tipo del documento:
Article