Clinical validity of karyotyping for the diagnosis of chromosomal imbalance following array comparative genomic hybridisation.
J Med Genet
; 48(12): 851-5, 2011 Dec.
Article
em En
| MEDLINE
| ID: mdl-21965346
ABSTRACT
BACKGROUND:
Array comparative genomic hybridisation (aCGH) represents a major advance in the ability to detect chromosomal imbalances (CI). A recent meta-analysis recommended aCGH for replacing karyotyping for patients with unexplained disabilities. However, favouring aCGH over karyotyping must be based on solid evidence due to the major implications of selecting a preferential diagnostic tool. METHODS ANDRESULTS:
A prospective study of 376 samples was conducted to assess the relevance of karyotyping after a first-tier aCGH in patients with unexplained disabilities. aCGH detected CI in 28.7% of the cases. Out of 376 patients, 288 had undergone parallel karyotyping testing 69.8% (201/288) showed similar results for both aCGH and karyotyping. For patients with a CI detected by aCGH, 7.9% (7/89) showed similar results for both aCGH and karyotyping. Among 20 patients with abnormal karyotyping, 13 showed dissimilar results compared to aCGHanalysis:
4 patients (1.4%) had balanced rearrangements and 9 patients (3.1%) had additional chromosomal anomalies unseen using aCGH. This rate of unseen chromosomal anomalies is far superior to the previously estimated 0.5-0.78% prevalence and affects 10.1% (9/89) of patients with CI detected by aCGH in the tested population.CONCLUSIONS:
Since the clinical significance of CI identified by aCGH might be influenced by such discrepancies between the two methods, these may in turn have an impact on clinical diagnosis and patient counselling. It is proposed that each genetic laboratory should evaluate the relevance of karyotyping for all first-tier abnormal aCGH results in order to include the genomic (chromosomal) aspects of the aCGH findings in the diagnosis.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Testes Genéticos
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Aberrações Cromossômicas
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Hibridização Genômica Comparativa
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Doenças Genéticas Inatas
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Cariotipagem
Tipo de estudo:
Diagnostic_studies
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Observational_studies
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Prognostic_studies
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Risk_factors_studies
Limite:
Female
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Humans
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Male
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article