BTG1 and acute lymphoblastic leukemia: This revealed a P2RY8–CRLF2 gene fusion, with no other clinically relevant variants, while a custom Taqman low density array indicated the patient also had the high-risk B-ALL subtype Ph-like ALL (6), Multiplex ligation-dependent probe amplification (MLPA) (MRC Holland, Amsterdam, the Netherlands; MLPA SALSA probe mixes P202, P335 and P327) confirmed iAMP21 and identified IKZF1 exon 2-3 and BTG1 exon 1-2 deletions.