Genetic testing improves the diagnosis of adult type hypolactasia in the Mediterranean population of Sardinia.

OBJECTIVE: Recently, the C/T-13910 polymorphism on chromosome 2q21 in North-European populations has been found completely associated with lactase activity and its genetic typing proposed as first-stage screening test for adult hypolactasia. However, the C/T-13910 variant in some sub-Saharan African groups is not a predictor of lactase persistence. In this work, we wanted to verify if in the Mediterranean island of Sardinia, located in Southern Europe, the C/T-13910 polymorphism may be useful or not for the diagnosis of adult type hypolactasia. DESIGN: Validation study of a genetic testing for adult type hypolactasia in Sardinians. SETTING: Brotzu Hospital and Microcitemico Hospital, Cagliari, Italy. SUBJECTS: The sample consisted in 84 Sardinian individuals (63 women and 21 men; range 20-73 years) selected from a group of 832 patients. METHODS: Genetic testing was compared to an improved test obtained by a combination of different breath hydrogen tests and clinical assessment. RESULTS: We found that all 49 individuals with lactose malabsorption, demonstrated by a combination of different breath hydrogen tests and clinical assessment, carried the C/C-13910 genotype associated with lactase non-persistence, 23 individuals with lactose normal absorption carried the C/T-13910 genotype associated with lactase persistence and only one person with the above phenotype showed a discordant C/C-13910 genotype. The genetic testing showed very high sensitivity, specificity, positive and negative predictive values of 100, 95.8, 98 and 100%, respectively. CONCLUSIONS: Sardinians, unlike some ethnic groups in sub-Saharan Africa, show the same genetic association of hypolactasia with the C/T-13910 variant as other North-European populations. The genetic testing for the C/T-13910 variant may contribute to improving the diagnosis of adult type hypolactasia.

Frequency of the thiopurine S-methyltransferase alleles in the ancient genetic population isolate of Sardinia.

BACKGROUND: Thiopurine S-methyltransferase (TPMT) is an enzyme involved in the normal metabolic inactivation of thiopurine drugs. Patients with intermediate or no TPMT activity are at risk of toxicity after receiving standard doses of thiopurine drugs and it was shown that inter-individual differences in response to these drugs is largely determined by genetic variation at the TPMT locus. OBJECTIVE: This study was designed to investigate in the Sardinian population the frequency distribution of four of the most common variants accounting for TPMT deficiency and to conduct comparative analyses with other populations in order to obtain insights into the main factors that have shaped diversity at the TPMT locus in Sardinia. METHODS: DNA was extracted in 259 Sardinians and the frequencies of allelic variants of TPMT were determined using polymerase chain reaction-restriction fragment length polymorphism technique. RESULTS: Among the 259 Sardinians genotyped, 6.95% were found to be heterozygous for one of four TPMT variants screened; for each variant the frequency estimate was 1.74%, 0.58%, 0.39% and 0.77% for TPMT*2, TPMT*3A, TPMT*3B and TPMT*3C respectively. CONCLUSIONS: Although Sardinia does not show reduced diversity at the TPMT locus, the spectrum of TPMT allele frequencies affords evidence of remarkable influence of genetic drift and founder effects throughout its population history. In the broad context of the European TPMT diversity, the Sardinians come out as outliers, an observation consistent with previous genetic inferences that Sardinia has features of a genetic isolate.

[Screening of hypertension in a community. Data from the "Camposampiero Project" (author's transl)]. / L'ipertensione arteriosa nella comunità: valutazione dello stato del controllo in una popolazione generale. Dati dal "Progetto di Camposampiero".

During the initial phase of the international "Community Control Programme of Hypertension" sponsored by W.H.O., and carried out in Italy by the Clinica Medica II of the University of Padua, a random sample of 5852 subjects was screened (11% of the whole population). The response rate was of 75.3%; the prevalence rate of hypertension (160 or 95), based on casual blood pressure readings, was 29.5%. Measures of the control of hypertension and other relevant results are: a 35.6% of all hypertensives were aware of their condition, and of these 41% were under treatment. Effective treatment of hypertension was seen in one 12.3% of all treated hypertensives (values lower than 16/95), while 14.2% of all hypertensives had values at or above 200 (systolic) or 120 (diastolic). 98.2% of all hypertensives were not under effective control. As a whole, control of hypertension was better in women and in elderly patients.