Just thought I would post something interesting I learned in a recent discussion with my MPN specialist regarding the connection between families and platelets.
Many of you are familiar with my situation. Age 30, platelets mildly elevated 430-455 for last 10 years. Driver mutation tests all negative. Currently being evaluated as possible ET triple-negative since all other blood counts are normal and reactive thrombocytosis ruled out.
Interestingly, I recently found out my mother (age 55) also has elevated platelets, fluctuating 435-470 as far back as her CBCs are readily available (2014). Granted, she has some health problems which may or may not contribute to these numbers. Told my MPN specialist this and he told me there is definitely a connection between platelets and family history, and that it comes in two forms:
1. Familial thrombocytosis (malignant/MPN) - A lot of us are familiar with this one. Some families seem to have an increased risk of acquiring certain driver mutations (JAK2, CALR exon 9, MPL exon 10). There are many people in this forum who have reported having children or siblings with an MPN and with the same mutation they have, despite these mutations not being able to be passed on to offspring (they are only acquired somatically after birth). Familial thrombocytosis falls under the MPN category since the mutations cause clonal disorders.
2. Hereditary thrombocytosis (benign) - There are rare mutations at different locations in JAK2, MPL, and thrombopoetin (THPO) genes, as well as in many other genes, that can be passed to offspring (germline mutations). While these mutations cause elevated platelets, the important distinction here is that hereditary thrombocytosis is usually viewed as "benign thrombocytosis" rather than a myeloid malignancy. According to my specialist, leukemic transformation has never been reported with true hereditary thrombocytosis.
It is important to note that families falling under either of these categories are extremely rare, with hereditary thrombocytosis being even more rare than familial thrombocytosis.
Unfortunately, my specialist was unable to say whether he thought my family situation fell under hereditary thrombocytosis since the platelet counts of both myself and my mother are so mildly elevated, saying he would assume the platelet counts of HT families to be much higher.
See the following paper for reference: