Abstract 5056

Introduction:

JAK2V617F point mutation have been confirmed to be one of the major molecular mechanism of BCR/ABL negative myeloproliferative disorders(MPD). Besides, some other gene mutations such as JAK2 exon12, MPL W515L/K, c-mpl and EPOR have extended the scope of the research in this field. Most of the MPD patients are sporadic and there are seldom reports in Chinese familial MPD. 2008 ASH metting we have reported in a Chinese family of MPD's findings, the two brothers in our hospital diagnosis for MPD (one is a PV, another is ET), then we investigated the 15 members of the family. We discovered that there were three male members carried the JAK2V617F mutation in this family, including the two MPD patients and their father, which affected in two generations. All the family members were confirmed as BCR/ABL, MPL W515L/K, c-mpl, and EPOR negative. Subsequently, in order to understand the existence of family members in addition to the gene JAK2 V617F mutation, the existence of JAK2 gene mutations in other parts of the? if other mutations in existence and the high incidence of family members of MPD? We focus on the cDNA full-length of JAK2 gene to provide some theory basis on the pathogenesis in MPD.

Methods:

A total of 15 family members were enrolled in our study, including 2 brothers of MPD patients (the older one was thrombocythemia (ET), and another is polycythemia vera (PV)) and the other members in the same family. The mRNA of mononuclear cells from peripheral blood sample was extracted according to the manufacturer's instruction (TAKARA). RT-PCR and DNA sequencing have been used to analyze the cDNA full-length of the JAK2 gene.

Results:

All of the samples can be analyzed for JAK2 cDNA full-length. 3 members carried the JAK2V617F mutation (1849G®T) in this family, including the two MPD patients and their father. And the older brother was homozygous mutation and the other two were heterozygous mutation. All of the 15 samples were JAK2 exon12 gene mutation negative. 2 persons who were the male ET patient's children had a heterozygous mutation (380G®A) in JAK2 exon 3, caused a glycine-to-asparticacid substitution at position 127. Besides, 13 persons had 489C®T mutation in exon 4 and 14 persons had 2490G→A mutation in exon 17 in this family, But they were both same-sense mutation.

Conclusion:

It is necessary to do routine analysis of blood and other related inspection for MPD patient's family members, so as to make diagnosis earlier. However, we are not sure that the sequencing results are unique to all the familial MPD and need to be confirmed by more cases. We still do not determine the current discovery point mutations have biological significance, still need to be further explored.

Disclosures:

No relevant conflicts of interest to declare.

Author notes

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Asterisk with author names denotes non-ASH members.