For example, larger gene deletion syndrome such as ‘TSC2 and PKD1 deletion’ has been described as a contiguous gene deletion syndrome, ‘Polycystic kidney disease, infantile severe, with tuberous sclerosis (OMIM: 600273)’, as PKD1 is in close proximity to TSC2 (van den Ouweland et al., 2011). This evidence concerns the gene PKD1 and polycystic kidney disease.