MED12-related Hardikar syndrome: Two additional cases and novel phenotypic features

Hardikar syndrome (HS) is a MED12-related ultra-rare multiple congenital malformation syndrome known to affect the gastrointestinal, cardiac, and genitourinary systems among other features including cleft lip/palate and pigmentary retinopathy. Only 10 patients affected with HS have been previously described in literature, of which seven were molecularly confirmed. We report a 20-year-old and a 13-month-old patient with HS diagnosed by exome sequencing bringing the total number of clinically diagnosed cases to 12 and MED12 associated to 9. We describe previously unreported molecular and clinical findings associated with HS and review all reported cases to permit prompt diagnosis, appropriate management, and genetic counseling of HS patients.