There are cases of familial MPN characterised by a number of rare germline mutations including RBBP6. The JAK2 46/1 combination of haplotypes is also associated with both JAK2 V617F positive and MPL positive MPN and is suggested to impact of a clonal advantage for any cells acquiring these mutations [67]. This evidence concerns the gene RBBP6 and myeloproliferative neoplasm.