2016). Additionally, the translated truncated N‐terminal peptide could serve as a dominant negative, competing for the intact signal peptide or processing protease of intact beta‐defensin 1 peptide encoded by the other DEFB1 allele. The heterozygous DEFB1 mutation was found in 6 PPROM cases (WES and follow‐up genotyping combined) and no term controls. The gene discussed is DEFB1; the disease is preterm premature rupture of the membranes.