Lessons from familial myeloproliferative disorders

Area of Science:

• Hematology
• Genetics
• Oncology

Background:

• Myeloproliferative disorders (MPDs) are typically sporadic, arising from acquired somatic mutations.
• However, familial cases suggest a role for germline mutations or genetic background in MPD development.
• These familial MPDs can be clinically indistinguishable from sporadic forms.

Purpose of the Study:

• To review familial myeloproliferative disorders, focusing on inherited predispositions.
• To discuss familial polycythemia vera (PV) and its inheritance patterns.
• To differentiate familial thrombocythemias and primary familial and congenital polycythemia (PFCP) from other MPDs.

Main Methods:

• Review of documented familial cases of myeloproliferative disorders.
• Analysis of inheritance patterns in familial polycythemia vera (PV).
• Comparison of clinical and laboratory features of familial thrombocythemias and PFCP with PV.

Main Results:

• Familial PV often presents as an autosomal dominant disorder with incomplete penetrance.
• Some families exhibit diverse MPDs, including PV, essential thrombocythemia (ET), chronic myelocytic leukemia (CML), and idiopathic myelofibrosis (IMF).
• Familial thrombocythemias result from germline mutations in thrombopoietin or MPL, causing polyclonal hereditary thrombocythemia.

Conclusions:

• Germline factors play a significant role in the pathogenesis of certain myeloproliferative disorders.
• Primary familial and congenital polycythemia (PFCP) shares features with PV but has distinct genetic underpinnings.
• Understanding familial MPDs is crucial for accurate diagnosis and distinguishing them from sporadic conditions.