A diagnostic approach to identifying submicroscopic 7p21 deletions in Saethre-Chotzen syndrome: Fluorescence in situ hybridization and dosage-sensitive Southern blot analysis
Kw. Gripp et al., A diagnostic approach to identifying submicroscopic 7p21 deletions in Saethre-Chotzen syndrome: Fluorescence in situ hybridization and dosage-sensitive Southern blot analysis, GENET MED, 3(2), 2001, pp. 102-108
Purpose: To report on the use of fluorescence in situ hybridization (FISH)
and dosage-sensitive Southern blot analysis in the molecular diagnosis of p
atients with Saethre-Chotzen syndrome, Methods: FISH and dosage-sensitive S
outhern blot analysis utilizing TWIST gene probes were performed on patient
s with Saethre-Chotzen syndrome but without an identifiable TWIST sequence
variation. Results: Four unrelated patients with a deletion of the TWIST ge
ne were identified by Southern blot; one of them had a complex chromosomal
rearrangement involving 7p21 and no apparent deletion by FISH, suggesting a
smaller deletion in the region including the TWIST gene. A fifth patient h
ad an abnormal TWIST gene fragment on Southern blot analysis that segregate
d with the disease in the family; FISH was normal in this patient, suggesti
ng a partial deletion or rearrangement in or near the gene. Conclusion: FIS
H and dosage-sensitive Southern blot analysis are useful diagnostic tools i
n Saethre-Chotzen syndrome without TWIST sequence variation.