Deletions and duplications of the 22q11.2 region in spermatozoa from DiGeorge/velocardiofacial fathers

Background: DiGeorge/velocardiofacial syndrome (DGS/VCFS) is the most common deletion syndrome in humans. Low copy repeats flanking the 22q11.2 region confer a substrate for non-allelic homologous recombination (NAHR) events leading to rearrangements. This study sought to identify DGS/VCFS fathers w...

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Detalhes bibliográficos
Autores: Vergés i Torroella, Laia, Molina, Oscar|||0000-0001-7585-4519, Geán, Esther, Vidal, Francesca|||0000-0002-0985-7348, Blanco, Joan|||0000-0003-0647-3856
Tipo de documento: artigo
Data de publicação:2014
País:España
Recursos:Universitat Autònoma de Barcelona
Repositório:Dipòsit Digital de Documents de la UAB
Idioma:inglês
OAI Identifier:oai:ddd.uab.cat:185128
Acesso em linha:https://ddd.uab.cat/record/185128
https://dx.doi.org/urn:doi:10.1186/s13039-014-0086-3
Access Level:Acceso aberto
Palavra-chave:Deletions and duplications
DiGeorge/velocardiofacial syndrome
Non-allelic homologous recombination
Spermatozoa
Descrição
Resumo:Background: DiGeorge/velocardiofacial syndrome (DGS/VCFS) is the most common deletion syndrome in humans. Low copy repeats flanking the 22q11.2 region confer a substrate for non-allelic homologous recombination (NAHR) events leading to rearrangements. This study sought to identify DGS/VCFS fathers with increased susceptibility to deletions and duplications at the 22q11.2 region in spermatozoa and to assess the particular contribution of intra-chromatid and/or inter-chromatid NAHR. Semen samples from nine DGS/VCFS fathers were analyzed by triple-color FISH using a probe combination that discriminated between normal, deleted and duplicated genotypes. Microsatellite analysis were performed in the parents and the affected children to determine the parental origin of the deleted chromosome 22. - Results: A significant increase in 22q11.2 deletions was observed in the sperm of two out of nine DGS/VCFS fathers (odds ratio 2.03-fold, P < 0.01), and in both cases the deletion in the offspring was transmitted by the father. Patients with significant increases in sperm anomalies presented a disturbed deletion:duplication 1:1 ratio (P < 0.01). - Conclusions: Altogether, results support that intra-chromatid NAHR is the mechanism responsible for the higher rate of sperm deletions, which is directly related to the transmission of the deleted chromosome 22 to offspring. Accordingly, the screening of sperm anomalies in the 22q11.2 region should be taken into account in the genetic counseling of DGS/VCFS families.