Summary: An increase in the total red cell mass of the blood. (Dorland, 27th ed)

Top Publications

  1. Martínez Avilés L, Besses C, Alvarez Larran A, Cervantes F, Hernández Boluda J, Bellosillo B. JAK2 exon 12 mutations in polycythemia vera or idiopathic erythrocytosis. Haematologica. 2007;92:1717-8 pubmed
    JAK2 exon 12 mutations were detected in 4 out of 20 polycythemia vera and idiopathic erythrocytosis V617F-negative patients and were only present in the myeloid lineage...
  2. Schnittger S, Bacher U, Haferlach C, Geer T, Muller P, Mittermuller J, et al. Detection of JAK2 exon 12 mutations in 15 patients with JAK2V617F negative polycythemia vera. Haematologica. 2009;94:414-8 pubmed publisher
    To further characterize JAK2 exon 12 mutations, we performed molecular screening in 409 patients with polycythemia vera or unclear erythrocytosis with unmutated JAK2V617. The frequency of JAK2exon12 mutations was 10/63 (15...
  3. Gordeuk V, Miasnikova G, Sergueeva A, Niu X, Nouraie M, Okhotin D, et al. Chuvash polycythemia VHLR200W mutation is associated with down-regulation of hepcidin expression. Blood. 2011;118:5278-82 pubmed publisher
    ..In conclusion, up-regulation of the hypoxic response leads to decreased expression of hepcidin that may be independent of increased erythropoietin levels and increased RBC counts. ..
  4. Huang L, Shen Y, Bulut G. Advances in understanding the pathogenesis of primary familial and congenital polycythaemia. Br J Haematol. 2010;148:844-52 pubmed publisher
    Primary familial and congenital polycythemia (PFCP) is an autosomal-dominant proliferative disorder characterized by erythrocytosis and hypersensitivity of erythroid progenitors to erythropoietin (Epo)...
  5. Ghosh M, Zhang D, Jeong S, Kovtunovych G, Ollivierre Wilson H, Noguchi A, et al. Deletion of iron regulatory protein 1 causes polycythemia and pulmonary hypertension in mice through translational derepression of HIF2α. Cell Metab. 2013;17:271-81 pubmed publisher
    ..We report here that mice with targeted deletion of Irp1 developed pulmonary hypertension and polycythemia that was exacerbated by a low-iron diet...
  6. van Rooijen E, Voest E, Logister I, Korving J, Schwerte T, Schulte Merker S, et al. Zebrafish mutants in the von Hippel-Lindau tumor suppressor display a hypoxic response and recapitulate key aspects of Chuvash polycythemia. Blood. 2009;113:6449-60 pubmed publisher
    ..The vhl mutants develop polycythemia with concomitantly increased epo/epor mRNA levels and erythropoietin signaling...
  7. Mathur A, Mo J, Kraus M, O Hare E, Sinclair P, Young J, et al. An inhibitor of Janus kinase 2 prevents polycythemia in mice. Biochem Pharmacol. 2009;78:382-9 pubmed publisher
    b>Polycythemia vera (PV) is a myeloproliferative disorder characterized by increased red cell mass and splenomegaly in the absence of secondary causes [Tefferi A., Spivak J.L., Polycythemia vera: scientific advances and current practice...
  8. Williams D, Kim A, Rogers O, Spivak J, Moliterno A. Phenotypic variations and new mutations in JAK2 V617F-negative polycythemia vera, erythrocytosis, and idiopathic myelofibrosis. Exp Hematol. 2007;35:1641-6 pubmed
    The chronic myeloproliferative disorders (MPD), polycythemia vera (PV), essential thrombocytosis, and idiopathic myelofibrosis (IMF), are characterized by a spectrum of clinical features and linked by common genetic lesions in JAK2 and ..
  9. Patnaik M, Tefferi A. The complete evaluation of erythrocytosis: congenital and acquired. Leukemia. 2009;23:834-44 pubmed publisher
    ..Clonal erythrocytosis is the diagnostic feature of polycythemia vera (PV) and is almost always associated with a JAK2 mutation (JAK2V617F or exon 12)...

More Information


  1. Hutton E, Hassan E. Late vs early clamping of the umbilical cord in full-term neonates: systematic review and meta-analysis of controlled trials. JAMA. 2007;297:1241-52 pubmed
    ..for outcomes of interest: infant hematologic status; iron status; and risk of adverse events such as jaundice, polycythemia, and respiratory distress. The meta-analysis included 15 controlled trials (1912 newborns)...
  2. Baffert F, Regnier C, De Pover A, Pissot Soldermann C, Tavares G, Blasco F, et al. Potent and selective inhibition of polycythemia by the quinoxaline JAK2 inhibitor NVP-BSK805. Mol Cancer Ther. 2010;9:1945-55 pubmed publisher
    ..Strikingly, the JAK2(V617F) mutation is found in nearly all patients suffering from polycythemia vera and in roughly every second patient suffering from essential thrombocythemia and primary myelofibrosis...
  3. Russell R, Sufan R, Zhou B, Heir P, Bunda S, Sybingco S, et al. Loss of JAK2 regulation via a heterodimeric VHL-SOCS1 E3 ubiquitin ligase underlies Chuvash polycythemia. Nat Med. 2011;17:845-53 pubmed publisher
    Chuvash polycythemia is a rare congenital form of polycythemia caused by homozygous R200W and H191D mutations in the VHL (von Hippel-Lindau) gene, whose gene product is the principal negative regulator of hypoxia-inducible factor...
  4. Rives S, Pahl H, Florensa L, Bellosillo B, Neusuess A, Estella J, et al. Molecular genetic analyses in familial and sporadic congenital primary erythrocytosis. Haematologica. 2007;92:674-7 pubmed
    ..All familial cases, varied in phenotype, presented the EPOR 1414C->G (Tyr426Stop) mutation. JAK2 mutations are not involved in the pathogenesis of primary congenital erythrocytosis. ..
  5. Weinberg I, Borohovitz A, Krichevsky S, Perlman R, Ben Yehuda A, Ben Yehuda D. Janus Kinase V617F mutation in cigarette smokers. Am J Hematol. 2012;87:5-8 pubmed publisher
    ..responsible for the constitutive activation of the erythropoietin receptor signaling pathway in most cases of polycythemia vera (PV). The mutation has also been described in healthy people...
  6. Minamishima Y, Moslehi J, Bardeesy N, Cullen D, Bronson R, Kaelin W. Somatic inactivation of the PHD2 prolyl hydroxylase causes polycythemia and congestive heart failure. Blood. 2008;111:3236-44 pubmed
    ..The latter is likely the result of hyperviscosity syndrome and volume overload, although a direct effect of chronic, high-level HIF stimulation on cardiac myocytes cannot be excluded. ..
  7. Perrotta S, Cucciolla V, Ferraro M, Ronzoni L, Tramontano A, Rossi F, et al. EPO receptor gain-of-function causes hereditary polycythemia, alters CD34 cell differentiation and increases circulating endothelial precursors. PLoS ONE. 2010;5:e12015 pubmed publisher
    Gain-of-function of erythropoietin receptor (EPOR) mutations represent the major cause of primary hereditary polycythemia. EPOR is also found in non-erythroid tissues, although its physiological role is still undefined...
  8. Ladroue C, Hoogewijs D, Gad S, Carcenac R, Storti F, Barrois M, et al. Distinct deregulation of the hypoxia inducible factor by PHD2 mutants identified in germline DNA of patients with polycythemia. Haematologica. 2012;97:9-14 pubmed publisher
    ..is the Arginine 200-Tryptophan mutant of the von Hippel-Lindau tumor suppressor gene, resulting in Chuvash polycythemia. This mutant displays a weak deficiency in hypoxia inducible factor ? regulation and does not promote ..
  9. Scott L, Tong W, Levine R, Scott M, Beer P, Stratton M, et al. JAK2 exon 12 mutations in polycythemia vera and idiopathic erythrocytosis. N Engl J Med. 2007;356:459-68 pubmed
    ..for valine at position 617 of the Janus kinase (JAK) 2 gene (JAK2), is often present in patients with polycythemia vera, essential thrombocythemia, and idiopathic myelofibrosis...
  10. Wiesener M, Münchenhagen P, Gläser M, Sobottka B, Knaup K, Jozefowski K, et al. Erythropoietin gene expression in renal carcinoma is considerably more frequent than paraneoplastic polycythemia. Int J Cancer. 2007;121:2434-42 pubmed
    ..Paraneoplastic polycythemia by cancerous overproduction of EPO is a rare event, but most frequently seen in patients with renal cell ..
  11. Cote C, Zilberberg M, Mody S, Dordelly L, Celli B. Haemoglobin level and its clinical impact in a cohort of patients with COPD. Eur Respir J. 2007;29:923-9 pubmed
    ..Anaemia was present in 116 (17%) patients and polycythemia in 40 (6%)...
  12. Gursoy A, Dogruk Unal A, Ayturk S, Karakus S, Nur Izol A, Bascil Tutuncu N, et al. Polycythemia as the first manifestation of Cushing's disease. J Endocrinol Invest. 2006;29:742-4 pubmed
    ..His follow-up for erythrocytosis had begun 2 yr earlier in another hospital and he had been diagnosed with polycythemia rubra vera...
  13. Sulahian R, Cleaver O, Huang L. Ligand-induced EpoR internalization is mediated by JAK2 and p85 and is impaired by mutations responsible for primary familial and congenital polycythemia. Blood. 2009;113:5287-97 pubmed publisher
    ..Furthermore, mutated EpoRs from primary familial and congenital polycythemia (PFCP) patients lacking the 3 important tyrosines do not bind p85 or internalize on stimulation...
  14. Prchal J. Classification and molecular biology of polycythemias (erythrocytoses) and thrombocytosis. Hematol Oncol Clin North Am. 2003;17:1151-8, vi pubmed
    ..In contrast, the molecular bases of polycythemia vera and essential thrombocythemia remain unknown, thus their diagnostic criteria are imprecise and their ..
  15. Zhuang Z, Yang C, Lorenzo F, Merino M, Fojo T, Kebebew E, et al. Somatic HIF2A gain-of-function mutations in paraganglioma with polycythemia. N Engl J Med. 2012;367:922-30 pubmed publisher
    ..in two patients, one presenting with paraganglioma and the other with paraganglioma and somatostatinoma, both of whom had polycythemia. The two mutations were associated with increased HIF-2α activity and increased protein half-life.
  16. Tomasic N, Piterkova L, Huff C, Bilic E, Yoon D, Miasnikova G, et al. The phenotype of polycythemia due to Croatian homozygous VHL (571C>G:H191D) mutation is different from that of Chuvash polycythemia (VHL 598C>T:R200W). Haematologica. 2013;98:560-7 pubmed publisher
    ..Only two known inherited homozygous VHL mutations exist and they cause polycythemia: Chuvash R200W and Croatian H191D...
  17. Hickey M, Lam J, Bezman N, Rathmell W, Simon M. von Hippel-Lindau mutation in mice recapitulates Chuvash polycythemia via hypoxia-inducible factor-2alpha signaling and splenic erythropoiesis. J Clin Invest. 2007;117:3879-89 pubmed
    ..protein (pVHL) is unique in that it is not associated with tumor development, but rather with Chuvash polycythemia, a heritable disease characterized by elevated hematocrit and increased serum levels of erythropoietin and VEGF...
  18. Al Sheikh M, Mazurier E, Gardie B, Casadevall N, Galacteros F, Goossens M, et al. A study of 36 unrelated cases with pure erythrocytosis revealed three new mutations in the erythropoietin receptor gene. Haematologica. 2008;93:1072-5 pubmed publisher
    ..Asn487Ser)] and another, a silent one (g.5799G>A). All were heterozygotes. In addition, 2 patients were positive for JAK2 (Val617Phe), and 2 reported elsewhere, were mutated in the PHD2 gene [c.606delG (p.Met202IlefsX71). ..
  19. Kim M, Kim S, Shin M, Lee D, Kim T, Kim K, et al. Human erythropoietin induces lung failure and erythrocytosis in transgenic mice. Mol Cells. 2007;23:17-22 pubmed
    ..The number of red blood cell, white blood cell and hemoglobin in the hEPO transgenic mice was higher than in normal mice. These results indicate that overexpression of hEPO is deleterious and can provoke lung failure and erythrocytosis. ..
  20. Yang C, Sun M, Matro J, Huynh T, Rahimpour S, Prchal J, et al. Novel HIF2A mutations disrupt oxygen sensing, leading to polycythemia, paragangliomas, and somatostatinomas. Blood. 2013;121:2563-6 pubmed publisher
    ..gain-of-function somatic mutations in patients presenting with multiple paragangliomas or somatostatinomas, and polycythemia. Here, we report 2 additional unique HIF2A mutations, which disrupt the hydroxylation domain recognized by ..
  21. Brna P, Gordon K, Dooley J, Price V. Manganese toxicity in a child with iron deficiency and polycythemia. J Child Neurol. 2011;26:891-4 pubmed publisher
    ..She had concurrent severe iron deficiency and polycythemia. Her magnetic resonance imaging (MRI) scan showed increased signal in the basal ganglia on T1-weighted images ..
  22. Rad F, Ulusakarya A, Gad S, Sibony M, Juin F, Richard S, et al. Novel somatic mutations of the VHL gene in an erythropoietin-producing renal carcinoma associated with secondary polycythemia and elevated circulating endothelial progenitor cells. Am J Hematol. 2008;83:155-8 pubmed
    ..With this regard, we analyzed a patient with EPO-producing clear-cell RCC and polycythemia. DNA extraction and sequencing analysis of the VHL gene were performed from the tumor and the adjacent normal ..
  23. Al Sheikh M, Moradkhani K, Lopez M, Wajcman H, Prehu C. Disturbance in the HIF-1alpha pathway associated with erythrocytosis: further evidences brought by frameshift and nonsense mutations in the prolyl hydroxylase domain protein 2 (PHD2) gene. Blood Cells Mol Dis. 2008;40:160-5 pubmed
    ..In addition to erythrocytosis, other complications, such as inflammatory arthromyalgia, have been observed in one case. ..
  24. Singh S, Verma R, Pradeep A, Leu K, Mortensen R, Young P, et al. Dynamic ligand modulation of EPO receptor pools, and dysregulation by polycythemia-associated EPOR alleles. PLoS ONE. 2012;7:e29064 pubmed publisher
    ..Consequently, these aspects of EPOR biology are not well defined, nor are actions of polycythemia- associated mutated EPOR alleles...
  25. Percy M, Furlow P, Beer P, Lappin T, McMullin M, Lee F. A novel erythrocytosis-associated PHD2 mutation suggests the location of a HIF binding groove. Blood. 2007;110:2193-6 pubmed
    ..These findings substantiate PHD2 as a critical enzyme controlling HIF and therefore Epo in humans, and furthermore suggest the location of an active site groove in PHD2 that binds HIF. ..
  26. Yoon D, Okhotin D, Kim B, Okhotina Y, Okhotin D, Miasnikova G, et al. Increased size of solid organs in patients with Chuvash polycythemia and in mice with altered expression of HIF-1alpha and HIF-2alpha. J Mol Med (Berl). 2010;88:523-30 pubmed publisher
    Chuvash polycythemia, the first hereditary disease associated with dysregulated oxygen-sensing to be recognized, is characterized by a homozygous germ-line loss-of-function mutation of the VHL gene (VHL(R200W)) resulting in elevated ..
  27. Percy M, Furlow P, Lucas G, Li X, Lappin T, McMullin M, et al. A gain-of-function mutation in the HIF2A gene in familial erythrocytosis. N Engl J Med. 2008;358:162-8 pubmed publisher
    ..Our functional studies indicate that this mutation leads to stabilization of the HIF-2alpha protein and suggest that wild-type HIF-2alpha regulates erythropoietin production in adults. ..
  28. Bourantas L, Chatzikyriakidou A, Dasoula A, Syrrou M, Bournatas K, Georgiou I. Absence of mutations of the EPO-receptor gene in Greek patients with familial polycythemia. Eur J Haematol. 2006;76:537-8 pubmed
  29. Percy M, McMullin M, Roques A, Westwood N, Acharya J, Hughes A, et al. Erythrocytosis due to a mutation in the erythropoietin receptor gene. Br J Haematol. 1998;100:407-10 pubmed
    ..The mutation (G6002A) has arisen independently in a Finnish family and de novo in this English boy. Patients with unexplained erythrocytosis and low serum Epo levels should be investigated for EpoR mutations. ..
  30. Vogel J, Kiessling I, Heinicke K, Stallmach T, Ossent P, Vogel O, et al. Transgenic mice overexpressing erythropoietin adapt to excessive erythrocytosis by regulating blood viscosity. Blood. 2003;102:2278-84 pubmed
    ..Apart from the nitric oxide-mediated vasodilation we reported earlier, adaptation to high hematocrit levels in tg mice involves regulated elevation of blood viscosity by increasing erythrocyte flexibility. ..
  31. Sokol L, Luhovy M, Guan Y, Prchal J, Semenza G, Prchal J. Primary familial polycythemia: a frameshift mutation in the erythropoietin receptor gene and increased sensitivity of erythroid progenitors to erythropoietin. Blood. 1995;86:15-22 pubmed
    Primary familial and congenital polycythemia (PFCP) is characterized by erythrocytosis with normal arterial PO2, blood P50, and serum erythropoietin (EPO) levels...
  32. van Rheenen P, Brabin B. Late umbilical cord-clamping as an intervention for reducing iron deficiency anaemia in term infants in developing and industrialised countries: a systematic review. Ann Trop Paediatr. 2004;24:3-16 pubmed
    ..In developing countries where fetal anaemia is common, the advantages of delayed cord-clamping might be especially beneficial. ..
  33. Balal M, Seyrek N, Karayaylali I, Paydas S. A unique form of polycythemia associated with minimal change disease. Med Princ Pract. 2004;13:366-8 pubmed
    To present a case with nephrotic syndrome due to minimal change disease and polycythemia. A 20-year-old female was admitted to our clinic for edema and severe proteinuria present with minimal change disease since the age of 7 years...
  34. Arcasoy M, Karayal A. Erythropoietin hypersensitivity in primary familial and congenital polycythemia: role of tyrosines Y285 and Y344 in erythropoietin receptor cytoplasmic domain. Biochim Biophys Acta. 2005;1740:17-28 pubmed
    ..carboxy-terminal region of EPOR have been described in some patients with primary familial and congenital polycythemia (PFCP), a disorder characterized by isolated erythrocytosis and increased sensitivity of erythroid progenitors ..
  35. Feliu Torres A, Eberle S, Roldan A, Gonzalez S, Sciuccati G. Hb Johnstown [beta109(G11)Val-->Leu]: A high oxygen affinity variant associated with beta0-thalassemia. Hemoglobin. 2004;28:335-8 pubmed
    ..The erythrocytosis and low values for actual P50 due to Hb Johnstown were more marked due to the co-inheritance of the beta0-thal. ..
  36. Pappas A, Delaney Black V. Differential diagnosis and management of polycythemia. Pediatr Clin North Am. 2004;51:1063-86, x-xi pubmed
    ..Fortunately, relatively few infants who have neonatal polycythemia or hyperviscosity develop complications attributable to their thick blood; however, controversy and the need ..
  37. Bushuev V, Miasnikova G, Sergueeva A, Polyakova L, Okhotin D, Gaskin P, et al. Endothelin-1, vascular endothelial growth factor and systolic pulmonary artery pressure in patients with Chuvash polycythemia. Haematologica. 2006;91:744-9 pubmed
    ..In Chuvash polycythemia, homozygous germline von Hippel-Lindau (VHL) 598C->T leads to up-regulation during normoxia of hypoxia ..
  38. Percy M, Mooney S, McMullin M, Flores A, Lappin T, Lee F. A common polymorphism in the oxygen-dependent degradation (ODD) domain of hypoxia inducible factor-1alpha (HIF-1alpha) does not impair Pro-564 hydroxylation. Mol Cancer. 2003;2:31 pubmed
    ..Thus, it is unlikely that this polymorphism accounts for the erythrocytosis in the group of IE patients studied. ..
  39. Dobo I, Donnard M, Girodon F, Mossuz P, Boiret N, Boukhari R, et al. Standardization and comparison of endogenous erythroid colony assays performed with bone marrow or blood progenitors for the diagnosis of polycythemia vera. Hematol J. 2004;5:161-7 pubmed
    ..collagen-based media was investigated in a multicentric study including 140 patients with polyglobuly (80 polycythemia vera (PV), 54 secondary erythrocytosis (SE), six idiopathic erythrocytosis (IE)) and 10 healthy donors...
  40. McMullin M, Bareford D, Campbell P, Green A, Harrison C, Hunt B, et al. Guidelines for the diagnosis, investigation and management of polycythaemia/erythrocytosis. Br J Haematol. 2005;130:174-95 pubmed
  41. Charache S, Weatherall D, Clegg J. Polycythemia associated with a hemoglobinopathy. J Clin Invest. 1966;45:813-22 pubmed
  42. Muszynski K, Ohashi T, Hanson C, Ruscetti S. Both the polycythemia- and anemia-inducing strains of Friend spleen focus-forming virus induce constitutive activation of the Raf-1/mitogen-activated protein kinase signal transduction pathway. J Virol. 1998;72:919-25 pubmed
    ..This pathway was activated in cells infected with the polycythemia-inducing strain of SFFV, which induces both proliferation and differentiation of erythroid cells in the absence ..
  43. Percy M, Zhao Q, Flores A, Harrison C, Lappin T, Maxwell P, et al. A family with erythrocytosis establishes a role for prolyl hydroxylase domain protein 2 in oxygen homeostasis. Proc Natl Acad Sci U S A. 2006;103:654-9 pubmed
    ..Our findings indicate that PHD2 is critical for normal regulation of HIF in humans. ..
  44. Liu E, Percy M, Amos C, Guan Y, Shete S, Stockton D, et al. The worldwide distribution of the VHL 598C>T mutation indicates a single founding event. Blood. 2004;103:1937-40 pubmed
    ..congenital defect of hypoxia-sensing homozygosity for VHL 598C>T mutation was recently identified in Chuvash polycythemia. Subsequently, we found this mutation in 11 unrelated individuals of diverse ethnic backgrounds...
  45. Rhoden E, Morgentaler A. Risks of testosterone-replacement therapy and recommendations for monitoring. N Engl J Med. 2004;350:482-92 pubmed
  46. Kralovics R, Indrak K, Stopka T, Berman B, Prchal J, Prchal J. Two new EPO receptor mutations: truncated EPO receptors are most frequently associated with primary familial and congenital polycythemias. Blood. 1997;90:2057-61 pubmed
    ..Primary familial and congenital polycythemia (PFCP; also known as familial erythrocytosis) is characterized by elevated red blood cell mass, low serum ..
  47. Gordeuk V, Stockton D, Prchal J. Congenital polycythemias/erythrocytoses. Haematologica. 2005;90:109-16 pubmed
    ..in red blood cell precursors, or from inherited conditions that cause low tissue oxygen tension and secondary polycythemia. Conditions of defective hypoxia sensing feature inappropriately normal or elevated serum erythropoietin (Epo) ..
  48. Percy M, McMullin M, Jowitt S, Potter M, Treacy M, Watson W, et al. Chuvash-type congenital polycythemia in 4 families of Asian and Western European ancestry. Blood. 2003;102:1097-9 pubmed
    The Chuvash form of polycythemia is an autosomal recessive disorder common to a large number of families in central Russia...
  49. Motohashi T, Nakamura Y, Osawa M, Hiroyama T, Iwama A, Shibuya A, et al. Increased cell surface expression of C-terminal truncated erythropoietin receptors in polycythemia. Eur J Haematol. 2001;67:88-93 pubmed
    Primary familial and congenital polycythemia (PFCP) is a disorder characterized by an increased number of erythrocytes despite normal blood oxygen pressure and a normal serum erythropoietin (EPO) level...
  50. Thiele J, Kvasnicka H, Zankovich R, Diehl V. The value of bone marrow histology in differentiating between early stage Polycythemia vera and secondary (reactive) Polycythemias. Haematologica. 2001;86:368-74 pubmed
    The diagnostic criteria of the Polycythemia Vera Study Group (PVSG), although generally acknowledged as the gold standard for establishing a diagnosis of polycythemia vera (PV), do not consider bone marrow features...
  51. Emhamed M, van Rheenen P, Brabin B. The early effects of delayed cord clamping in term infants born to Libyan mothers. Trop Doct. 2004;34:218-22 pubmed
    ..It is a safe, simple and low cost delivery procedure that should be incorporated in integrated programmes aimed at reducing iron deficiency anaemia in infants in developing countries. ..
  52. Ang S, Chen H, Gordeuk V, Sergueeva A, Polyakova L, Miasnikova G, et al. Endemic polycythemia in Russia: mutation in the VHL gene. Blood Cells Mol Dis. 2002;28:57-62 pubmed
    Chuvash polycythemia (CP) is an autosomal recessive condition that is endemic in the Russian mid-Volga River region of Chuvashia...
  53. Zhang J, Randall M, Loyd M, Li W, Schweers R, Persons D, et al. Role of erythropoietin receptor signaling in Friend virus-induced erythroblastosis and polycythemia. Blood. 2006;107:73-8 pubmed
    Friend virus is an acutely oncogenic retrovirus that causes erythroblastosis and polycythemia in mice...