The availability of clinical, laboratory and genetic data on 12.517 inhabitants of 10 villages in a secluded area of Sardinia (Ogliastra) allowed us to address the theme of the prevalence of thrombocytopenia in general population, a matter that has never been extensively investigated. High density SNPs analysis and genealogical records demonstrated a high genetic differentiation among such villages. We observed a platelet count lower than 150x109/L in 3.2% of females and 4.8% of males, with a mean value of 3.9% in the entire population. Thrombocytopenia was mild (100-150x109 platelets/L), asymptomatic and not associated with other cytopenias or overt disorders in most cases. Its prevalence was quite different in different villages, with values ranging from 1.5% to 6.8%. Interestingly, it was negatively correlated with the prevalence of a mild form of thrombocytosis, which ranged from 0.9 to 4.5%. The analysis of platelet counts in different villages revealed that their distribution curves were roughly Gaussian, and that they were shifted to the left in the populations with the highest prevalence of thrombocytopenia and the lowest of thrombocytosis, while they were shifted to the right in those with opposite characteristics. Analysis of platelet counts in different classes of age revealed that platelet number progressively decreased during ageing. As a consequence, thrombocytopenia was nearly absent in young people and its prevalence regularly increased during the lifetime. The opposite occurred for thrombocytosis. Given the high genetic differentiation among Ogliastra villages with "high" and "low" platelet counts and the substantial heritability of this quantitative trait (54%), we concluded that the propensity to present mild and transient thrombocytosis in the youth and to acquire mild thrombocytopenia during ageing are new genetic traits. Further investigation is required to ascertain whether this conclusion applies also to populations other than those of Ogliastra.
News on thrombocytopenia and thrombocytosis from the study of sardinian genetic isolates
Simona Vaccargiu;Mario Pirastu;Ginevra Biino
2010
Abstract
The availability of clinical, laboratory and genetic data on 12.517 inhabitants of 10 villages in a secluded area of Sardinia (Ogliastra) allowed us to address the theme of the prevalence of thrombocytopenia in general population, a matter that has never been extensively investigated. High density SNPs analysis and genealogical records demonstrated a high genetic differentiation among such villages. We observed a platelet count lower than 150x109/L in 3.2% of females and 4.8% of males, with a mean value of 3.9% in the entire population. Thrombocytopenia was mild (100-150x109 platelets/L), asymptomatic and not associated with other cytopenias or overt disorders in most cases. Its prevalence was quite different in different villages, with values ranging from 1.5% to 6.8%. Interestingly, it was negatively correlated with the prevalence of a mild form of thrombocytosis, which ranged from 0.9 to 4.5%. The analysis of platelet counts in different villages revealed that their distribution curves were roughly Gaussian, and that they were shifted to the left in the populations with the highest prevalence of thrombocytopenia and the lowest of thrombocytosis, while they were shifted to the right in those with opposite characteristics. Analysis of platelet counts in different classes of age revealed that platelet number progressively decreased during ageing. As a consequence, thrombocytopenia was nearly absent in young people and its prevalence regularly increased during the lifetime. The opposite occurred for thrombocytosis. Given the high genetic differentiation among Ogliastra villages with "high" and "low" platelet counts and the substantial heritability of this quantitative trait (54%), we concluded that the propensity to present mild and transient thrombocytosis in the youth and to acquire mild thrombocytopenia during ageing are new genetic traits. Further investigation is required to ascertain whether this conclusion applies also to populations other than those of Ogliastra.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
