Diagnosis of XIAP deficiency

A key step is your specialist recognising the clinical pattern as possibly being due to XIAP deficiency. A wide range of blood tests will be carried out, including a full blood count to look for low numbers of each type of blood cell, as well as more specialised tests to check liver function and look for signs and causes of infection. Some tests will need to be performed in a specialist laboratory and will take several days. The diagnosis of XIAP deficiency is confirmed by measuring a low level of XIAP protein in blood cells, as well as genetic tests to identify the underlying genetic change.

Other samples, such as bone marrow or lymph node tissue, may be needed
depending on the patient’s condition. If there are neurological symptoms, a sample of cerebrospinal fluid may be taken by lumbar puncture. Inflammation of the gut may need to be assessed by looking inside with a flexible endoscope (while the child is asleep under anaesthetic), and many children will need specialised imaging using techniques such as ultrasound, MRI or CT scan. Your medical team will guide you through this process.