Structural variation in SBDS gene, with loss of exon 3, in two Shwachman-Diamond patients

We recently found two families, each of them with two affected children (UPN 42, UPN 43 and UPN 61, UPN 76), carrying only the [c.258+2T>C] mutation; no other DNA changes was found after complete sequencing analysis of all five exons and their flanking intronic regions of SBDS. In both families, the clinical picture of the patients completely fits the diagnostic criteria. Western-blot analysis using SBDS antibody did not demonstrate any SBDS protein in these patients, suggesting the presence of a more complex anomaly on the second allele