CARDIAC GENE-EXPRESSION OF ATRIAL-NATRIURETIC-PEPTIDE AND BRAIN NATRIURETIC PEPTIDE IN TRISOMIC FETUSES

Objective: To investigate whether the increased nuchal translucency of trisomic fetuses is the consequence of heart failure by examining car diac expression of atrial natriuretic peptide and brain natriuretic pe ptide genes. Methods: Cardiac atrial natriuretic peptide and brain nat riuretic peptide messenger RNA (mRNA) levels were measured in fetal he arts from 15 pregnancies affected by trisomy 21 or 18 at 12-16 weeks' gestation and from 30 normal controls at 10-20 weeks. Results: In norm al fetuses, mRNA levels of atrial natriuretic peptide decreased, but l evels of brain natriuretic peptide did not change significantly with g estation. In trisomic fetuses, mRNA levels of both atrial natriuretic peptide and brain natriuretic peptide were significantly higher than i n gestational age-matched normal controls. Conclusion: These data demo nstrate that atrial natriuretic peptide and brain natriuretic peptide genes are transcribed prenatally, and the findings in trisomic fetuses suggest that the increased translucency of trisomic fetuses may be th e consequence of heart failure.