Decline of lactase activity and c/t-13910 variant in Sardinian childhood

SCHIRRU E;CORONA V;USAI SATTA P;SCARPA M;CUCCA F;DE VIRGILIIS S;ROSSINO, ROSSANO;FRAU F;MACIS MD;JORES RD;CONGIA M.

2007-01-01

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Abstract

Our study aims to determine the age of onset of adult-type hypolactasia in Sardinians, and to establish the age at which genotyping of the C/T-13910 variant can be used reliably in the diagnosis of lactose malabsorption. PATIENTS AND METHODS: A lactose breath hydrogen test was given to 383 randomly selected patients, from 3 to 19 years old. RESULTS: The C/C-13910 genotype was found in 90% of patients; the frequency of the positive lactose breath hydrogen test increased with age and reached a prevalence of 85% at 9 years. CONCLUSIONS: In Sardinians, adult-type hypolactasia becomes phenotypically evident in all individuals older than 9 years, suggesting that this should be considered the minimum age at which the genetic test for lactase nonpersistence should be applied.