Background: Although imperforate hymen occurs in approximately 0.1% of female newborns, familial occurrence of imperforate hymen has been reported only once.
Cases: We report two families in which imperforate hymen was diagnosed in three siblings of each family. One family is described in detail; the patients were two postmenarchal young women and one premenarchal girl.
Conclusion: Imperforate hymen usually occurs sporadically but can be familial. We advise screening all female newborns and children for vaginal patency, especially family members of an affected child. Identification of other families with a similar problem might point to a specific mode of inheritance.