PTEN and PTEN hamartoma tumor syndrome: PTEN Hamartoma Tumour Syndrome (PHTS) is an autosomal dominant tumour predisposition syndrome resulting from whole exonic deletions, truncating, splicing, missense or promoter mutations with diverse functional effects on PTEN including haploinsufficiency, lost or reduced phosphatase activity, dominant-negative and aberrant function and/or localisation [56–59].