Premature Monozygotic Twins With Bilateral Choanal Atresia: A Case Report

INTRODUCTION Choanal atresia is an uncommon disorder that is the most common cause of complete nasal obstruction in the neonate. It occurs when the posterior choanae fail to develop properly. The published incidence varies from one in 5,000 to one in 8,000 live births.1 Both sexes are affected but reports suggest a female predominance of two to one.2 Unilateral cases are more common than bilateral cases and bony atresia (90%) is more common than membranous atresia (10%). However, some publications suggest that mixed bony–membranous anomalies may have the highest incidence.3 The genetic aspects of choanal atresia remain unclear. We report a case of premature, monozygotic twins who both presented with bilateral bony choanal atresia and no other syndromic genetic defects.