SMA carrier testing--validation of hemizygous SMN exon 7 deletion test for the identification of proximal spinal muscular atrophy carriers and patients with a single allele deletion.
Eur J Hum Genet
; 8(2): 79-86, 2000 Feb.
Article
en En
| MEDLINE
| ID: mdl-10757638
ABSTRACT
To facilitate the detection of carriers of a hemizygous survival motor neuron (SMN) exon 7 deletion we have modified the quantitative SMN exon 7 assay described by McAndrew et al (1997). The major changes include quantitative analysis of the amount of SMN exon 7-specific fluorescently-labelled PCR product on an automated sequencer, and the monitoring of the completeness of a DraI digestion necessary to distinguish the PCR products of exons 7 of SMN and its copy gene. In our method the amount of SMN exon 7 PCR product is compared with the amount of a co-amplified PCR product of the retinoblastoma (RB1) exon containing a DraI restriction site. By co-amplification using the same primers of plasmids included in the reaction as internal standards containing SMN exon 7 with a 36-nucleotide deletion and RB1 exon 13 with a 19-nucleotide deletion, respectively, the relative amplification efficacy can be monitored. The assay has been validated in 63 ascertained carriers and 28 ascertained non-carriers. The sensitivity of the test is approximately 97%, the specificity approaches 100%. In four out of six SMA patients without a homozygous deletion we detected a hemizygous deletion. The implications of the use of this assay for carrier testing and for confirmation of the clinical diagnosis of SMA are discussed.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Atrofia Muscular Espinal
/
Exones
/
Tamización de Portadores Genéticos
/
Proteínas del Tejido Nervioso
Tipo de estudio:
Diagnostic_studies
/
Guideline
Límite:
Female
/
Humans
/
Male
Idioma:
En
Revista:
Eur J Hum Genet
Asunto de la revista:
GENETICA MEDICA
Año:
2000
Tipo del documento:
Article
País de afiliación:
Países Bajos