OBJECTIVETo comprehend the abnormalities of JAK2, c-mp, EPOR, MPW515L/K and TET2 genes in patients with familial myeloproliferative neoplasm (MPN) and their relatives, and to explore mechanism of MPN pathogenesis.

METHODSThe complete blood counts of 2 brothers diagnosed with MPN in out hospital and their family members (15 persons in together) were performed, and bone marrow (BM) examinations in patients with abnormal blood count were performed PCR, DNA sequencing were used to evaluate the expression of related genes.

RESULTSThe elder brother was diagnosed with essential thrombocythemia (ET), the younger one was polycythemia vera (PV), and others had no clinical manifestation. The third MPN patient was diagnosed based on the blood count and BM examination. The PCR and sequencing results showed that there was JAK2V617F mutation in 3 patients, the elder brother was homozygous, the younger and their father were heterozygous. There were no BCR/ABL fusion gene and c-mp, EPOR, MPW515L/K, TET2 gene mutation in any member. By sequencing the full-length cDNA of familia JAK2 gene, we found that G380A heterozygous mutation was detected in 2 patients, which changed glycine at 127 into aspartic acid, C489T mutation was detected in 13 patients, G2490A mutation in 14, but both of them were synonymous mutations.

CONCLUSIONSJAK2V617F is one of the important indicators to diagnose MPN. The JAK2V617F mutation of this family involves two generations. For newly diagnosed MPN patients, their family members should consider screening, so some familial patients can be diagnosed as early as possible. Gene mutation besides JAK2V627F can be detected by sequencing the full-length of JAK2 gene.