An excess of tetralogy of Fallot in Malta.

STUDY OBJECTIVE To estimate birth prevalence of tetralogy of Fallot (TF) in Malta. DESIGN Retrospective data collection and analysis, and comparison with earlier epidemiological studies dealing with congenital heart disease. SETTING Regional hospital providing exclusive diagnostic and follow up services for the entire country of Malta. PATIENTS All Maltese live births diagnosed as having TF. MAIN RESULTS The birth prevalence of TF in Malta for the period 1980-1994 was 0.64/1000 live births (95% confidence intervals 0.48, 0.85/1000 live births). This was significantly higher than previously reported in the medical literature. CONCLUSIONS The Maltese gene pool seems to have a genetic predisposition towards live births with TF. Population genetic studies with emphasis on the prevalence of 22q11 microdeletion may yield clues regarding the cause of the high rate of this condition.