SPINK1 and alkaline phosphatase measurement: A 2019 study demonstrated that patients with AP who had SPINK1 mutations developed RAP more quickly.358 In another study comparing 87 patients with RAP to those who had a sentinel attack and healthy individuals, the frequencies of the PRSS1 p.R122H mutation, SPINK1 p.N34S variant, and PRSS3 p.E32del variant were found to be higher in the RAP group.359 Additionally, a study showed that while the SPINK1 N34S polymorphism did not increase the risk of a sentinel attack, it did increase the risk of recurrent attacks (OR: 19.1, 95% CI: 2.4-149.6).360