BMPR1A, the gene associated with JPS, shares the same chromosomal region as PTEN (10q23.2): if large deletions encompass these genes the phenotypic expression can include features of both PHTS and JPS, most typically with juvenile polyposis of infancy (JPI), an aggressive subtype of JPS characterized by severe gastrointestinal symptoms, including diarrhea, intestinal bleeding, rectal prolapse, protein-losing enteropathy with a high risk of intussusception and consequently high infant mortality (Jelsig et al., 2014). This evidence concerns the gene BMPR1A and juvenile polyposis of infancy.