X-linked Lymphoproliferative Syndrome (XLP)
Utility: 1) Evaluate the presence of SLAM-associated protein (SAP) and X-linked inhibitor of apoptosis (XIAP) in peripheral blood.
2) Diagnostic screen for X-Linked Lympho¬proliferative Syndrome (XLP), types 1 and 2.
3) Detection of carrier status in female relatives of XLP patients.
Specimen: 8 - 15 mL peripheral blood in sodium heparin (green top).
CPT codes: 86359, 86360, 86355, 86357, 88184, 88185 x 15, 88188.
Clinical indication/general description
XLP, also called Duncan disease, is a rare X-linked disorder affecting predominantly male patients. Mutations in SH2D1A gene encoding the signaling lymphocyte activation molecule (SLAM)-associated protein (SAP) cause XLP1. XLP type 2 (XLP2) is caused by mutations in BIRC4 gene encoding the XIAP protein.
Intracellular protein expression of SAP and XIAP in peripheral blood lymphocytes is determined by flow cytometry. Deficient expression of SAP and XIAP in lymphocytes is associated with XLP type 1 or XLP type 2, respectively.