In our hematology department, we have a 3yo male with a recent history of multiple infections, anemia, thrombocytopenia, splenomegaly, lymphadenopathy, and CD4 lymphopenia. He also has a history of CMV positivity and elevated IgG levels. PID NGS panel found a pathogenic GOF mutation in the PIK3CD gene, c.3061G>A, p.Glu1021Lys. This is a mutation that has been reported in several individuals with PI3Kδ syndrome.
In view of cytopenias and organomegaly, we intend to start treatment shortly. Last year during one of our monthly conferences we discuss the use of Idelalisib as an alternative to Sirolimus. The clinical trial does not appear to include children <12 years of age. We are currently thinking of initiating sirolimus but wanted to see if there are any other alternatives.
One of my colleagues have sent it to the CIS listserv so I will update y'all if we get any additional ideas.