Interstitial deletions encompassing SH2D1Aexon 1 are present in patients HLH-PZ and HLH-OT.

(A) Nested PCR analysis of SH2D1A exon 1 reveals no detectable product in patients HLH-PZ or HLH-OT, in comparison to a normal patient (denoted as “+”), indicating the presence of interstitial genomic deletions. Amplification of the centromeric sequence gSH2D1A-L reveals a product in patient HLH-PZ, establishing an approximate centromeric boundary for the deletion in this patient. The gSH2D1A-L is absent in HLH-OT, indicating the presence of a larger deletion, the centromeric boundary of which was not further mapped. “M” denotes the 123-base pair (bp) ladder, and “−” the negative control (no input DNA). (B) Schematic representation of the wild-type SH2D1A genomic locus and the constitutional deletions in these patients. SH2D1A exons are shown as black boxes, and the gSH2D1A-L marker as a hatched box.