Frequency of low-level and high-level mosaicism in sporadic retinoblastoma: genotype-phenotype relationships.
J Hum Genet
; 65(2): 165-174, 2020 Jan.
Article
en En
| MEDLINE
| ID: mdl-31772335
ABSTRACT
Somatic mutational mosaicism is a common feature of monogenic genetic disorders, particularly in diseases such as retinoblastoma, with high rates of de novo mutations. The detection and quantification of mosaicism is particularly relevant in these diseases, since it has important implications for genetic counseling, patient management, and probably also on disease onset and progression. In order to assess the rate of somatic mosaicism (high- and low-level mosaicism) in sporadic retinoblastoma patients, we analyzed a cohort of 153 patients with sporadic retinoblastoma using ultra deep next-generation sequencing. High-level mosaicism was detected in 14 out of 100 (14%) bilateral patients and in 11 out of 29 (38%) unilateral patients in whom conventional Sanger sequencing identified a pathogenic mutation in blood DNA. In addition, low-level mosaicism was detected in 3 out of 16 (19%) unilateral patients in whom conventional screening was negative in blood DNA. Our results also reveal that mosaicism was associated to delayed retinoblastoma onset particularly in unilateral patients. Finally we compared the level of mosaicism in different tissues to identify the best DNA source to identify mosaicism in retinoblastoma patients. In light of these results we recommended analyzing the mosaic status in all retinoblastoma patients using accurate techniques such as next-generation sequencing, even in those cases in which conventional Sanger sequencing identified a pathogenic mutation in blood DNA. Our results suggest that a significant proportion of those cases are truly mosaics that could have been overlooked. This information should be taking into consideration in the management and genetic counseling of retinoblastoma patients and families.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Retinoblastoma
/
Mosaicismo
Tipo de estudio:
Diagnostic_studies
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Etiology_studies
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Incidence_studies
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Observational_studies
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Prognostic_studies
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Risk_factors_studies
Límite:
Humans
Idioma:
En
Revista:
J Hum Genet
Asunto de la revista:
GENETICA MEDICA
Año:
2020
Tipo del documento:
Article
País de afiliación:
España