Large scale deletions in the GPC3 gene may account for a minority of cases of Simpson-Golabi-Behmel syndrome

Aims of the study-To identify the proportion and type of deletions present in the glypican 3 (GPC3) gene in a group of patients with Simpson- Golabi-Behmel syndrome (SOBS). Subjects and methods-PCR analysis using primer pairs which amplify fragments from each of the eight exons of the GPC3 gene was carried out in a series of 18 families with SOBS (approximately half of reported cases). Results-Deletions were detected in only five families (one reported previously). We found deletions in all exons of the gene except exon 3. Conclusions-Our results suggest that large scale deletions may be less common in SGBS than was originally thought. One patient, with an exon 4 and 5 deletion, lacked the characteristic facial dysmorphic features. This raises the possibility of involvement of GPC3 gene defects in a wider range of overgrowth disorders.