Background: Reports of recurrent isolated hypoplastic left heart syndrome have been infrequent, and the genetic basis of this occurrence is not well understood.
Case: A 32-year-old woman with a noncontributory medical and family history terminated her first pregnancy after the fetus was diagnosed with hypoplastic left heart syndrome. Chromosomes were normal and no extracardiac anomalies were found at autopsy. In one subsequent pregnancy, a healthy live-born neonate was delivered, but in two other pregnancies isolated hypoplastic left heart syndrome was diagnosed again.
Conclusion: Parents with an infant affected with hypoplastic left heart syndrome have been quoted a recurrence risk of 2%. The occurrence of isolated hypoplastic left heart syndrome in three siblings suggests that this anomaly has an autosomal recessive mode of inheritance. Consequently, the possibility of a recurrence risk higher than 2% should be included during counseling.