A

                              Guide to  

                          the Genetics of

                  Polycythaemia Vera (Rubra)

                                   &

                  Essential Thrombocythaemia

                              'PV & ET'


Mitochondrial DNA Haplogroups


If Polycythaemia Vera is indeed inherited down the maternal line, then it might be expected there will be a correlation between the mitochondrial DNA (mtDNA) haplogroups and PV. Mitochondria pass down the maternal line, going in each generation from the mother to her children. A son does get his mitochondria from his mother, but does not pass any to his children. However, a daughter passes her mitochondria to all of her children. The mtDNA sequence in a person has a distinctive pattern of mutations, and this may be found in just close family members, but more likely in many thousands of relations. At present over 5,000 mtDNA haplogroups have been identified by their 'defining' mutations; and each is linked to a particular geographical area. In effect mtDNA haplogroups split the world population into small groups; with each being given a particular label. - Haplogroups labels starting with: H, V, J, T, U, K are European. - Haplogroups labels starting with L are African - Haplogroups with labels starting with I, N, X are European and Asian - and the remaining haplogroups are Asian. Americans are in European, Asian, or African haplogroups depending on their maternal line ethnicity. The haplogroups can be arranged as a 'phylogenetic tree' and the complete tree can be seen at: https://www.phylotree.org/tree/index.htm It is unfortunate that a list of mitochondrial haplogroups have not been made available for any of the groups surveyed in the past. So it will extremely useful if any person with a diagnosis of PV or ET, or a sibling, who knows their mitochondrial haplogroup lets me add their details to the list below: Type mtDNA label Test used Identifier PV H1-C16239T FTDNA-FGS 'DC' PV H3c2b1 FTDNA-FGS 'CK' ET H7 23andMe '--' Mitochondrial DNA testing is available from https://www.23andme.com - the test looks at 20% of the mtDNA However, the Full Genome Sequencing (FGS) from https://www.familytreedna.com gives a more accurate result, as 100% of the mtDNA is sequenced.