TNNI2 and digestive system disorder: A gene‐based association was also found between PS and TNNI2. TNNI2 (Homo sapiens troponin I2, fast skeletal type), is part of a collection of genes involved in governing muscle function, and mutations in this gene are associated with digestive system disease (Jostins et al., 2012) and muscle contractures (Sung et al., 2003; Toydemir & Bamshad, 2009).