SHROOM2 and Familial adenomatous polyposis: Closa et al. hypothesized that since GPR143 and SHROOM2 may both play a role in retinal pigmentation and patients with familial adenomatous polyposis syndrome can also develop benign RPE lesions (known as congenital hypertrophy of retinal pigment epithelium lesions) mutations in the region of Xp22.2 may increase the risk for developing colorectal cancer (Díaz-Llopis and Menezo, 1988; Galiatsatos and Foulkes, 2006; Closa et al., 2014, https://rarediseases.org/rare-diseases/familial-adenomatous-polyposis/, accessed 4 January 2022).