Inheritance of the chronic myeloproliferative neoplasms. A systematic review

This systematic review investigated the inheritance of the classical chronic myeloproliferative neoplasms (MPNs) including polycythemia vera (PV), essential thrombocythemia (ET), primary myelofibrosis (PMF) and chronic myelogenous leukemia (CML). Sixty-one articles were included and provided 135 families with a total of 341 participants distributed to various subtypes of MPN: 50% PV, 23% ET, 14% PMF, 10% CML and 3% non-MPN hematological disorder. Women developed the disease earlier than men (43.1 years vs 47.3 years; p = 0.074), while the general average age of onset was 46 years, notably younger than sporadic cases. The clinical phenotype of the families showed a homogenous (67%) and a heterogeneous (33%) pattern, with the majority being PV-PV pairs (36%) and PV-PMF pairs (17%), respectively. This observation suggests that the susceptibility gene (or genes) is not restricted to one subtype supporting the hypothesis of a mutation in an early multipotent stem cell. Furthermore, a major subgroup of families provided evidence of an autosomal dominant (AD) inheritance with reduced penetrance. This study suggests that the origin of MPNs may occur in at least three different settings: (i) a sporadic, (ii) genetic heterogeneity with polygenetic and environmental impact and (iii) a familial phenotype following an AD inheritance.