An unbalanced 5;22 translocation in a patient with features of VCFS: Confirmation by FISH of loss of the DGS/VCFS critical region
- Baylor College of Medicine, Houston, TX (United States)
- Georgia Neurological Institute, Savannah, GA (United States)
A 14-month-old male with a history of ventricular septal defect (VSD) and cleft lip and palate (CL/P) was referred for evaluation because of growth retardation, developmental delay and hypotonia. The initial cytogenetic analysis was 45,XY,-5,-22,+der(5)t(5q:22q). Determination of breakpoints 5q35.3 and 22q11.2 were made on G-banded chromosomes with band lengths of over 550. However, with both regions being light G bands, it was difficult to tell if the break in 22 was proximal to or distal to the DiGeorge syndrome/velocardiofacial syndrome (DGS/VCFS) critical region. Since the patient had a VSD and CL/P, velocardiofacial syndrome and a deletion of the DGS/VCFS critical region was suspected. FISH analysis of the derivative chromosome was performed with a cocktail containing two probes (ONCOR), D22S75, which maps to the DGS/VCFS region in 22q11.2 and D22S39, which maps to 22q13.3 and is used as a control for the presence of chromosome 22. Three fluorescent signals were observed, two on the normal 22 and the third on the terminal end of the derivative 5 chromosome verifying the translocation of 22q to 5q. No signal was observed for D22S75 on the proximal part of the translocated segment, verifying a deletion of the DGS/VCFS region in a patient whose clinical evaluation is consistent with velocardiofacial syndrome. Experiments with additional probes are underway to determine the deletion boundaries.
- OSTI ID:
- 133759
- Report Number(s):
- CONF-941009--
- Journal Information:
- American Journal of Human Genetics, Journal Name: American Journal of Human Genetics Journal Issue: Suppl.3 Vol. 55; ISSN AJHGAG; ISSN 0002-9297
- Country of Publication:
- United States
- Language:
- English
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