Abstract
We report a child with clinical findings consistent with Werdnig-Hoffmann disease (spinal muscular atrophy type I) who was found not to have the homozygous absence of the survival motor neurone (SMN(T)) gene observed in ~ 95% of spinal muscular atrophy patients. A quantitative PCR based dosage assay for SMN(T) copy number showed that this patient possessed a single copy of the SMN(T) gene. Heteroduplex and sequence analysis of the remaining copy of SMN(T) showed a 2 base pair deletion within exon 4 which produces a frameshift and premature termination of the deduced SMN(T) protein. This protocol of initial SMN(T) gene dosage analysis followed by mutation detection allows identification of SMA compound heterozygotes (patients lacking one copy of SMN(T) and having another mutation in their other copy), thereby increasing the sensitivity of SMA molecular diagnosis.
Original language | English (US) |
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Pages (from-to) | 674-676 |
Number of pages | 3 |
Journal | Journal of medical genetics |
Volume | 35 |
Issue number | 8 |
DOIs | |
State | Published - 1998 |
Externally published | Yes |
Keywords
- Quantitative PCR
- Spinal muscular atrophy
- Survival motor neurone gene
ASJC Scopus subject areas
- Genetics
- Genetics(clinical)