Here, we report a 6‐year‐old male with BCP‐ALL with the t(5;14)(q31;q32) translocation and harboring a novel constitutional PAX5 variant (NM_016734.3:c.[295dup];[=], p.[(Ile99Asnfs*3)];[(=)]). Here, PAX5 is linked to acute lymphoblastic leukemia.