Hydrometrocolpos, postaxial polydactyly, and hypothalamic hamartoma in a patient with confirmed Pallister-Hall syndrome: a clinical overlap with McKusick-Kaufman syndrome.

We present a preterm-born girl with polydactyly of both hands and massive hydrometrocolpos, the latter due to vaginal atresia. This association led initially to the diagnosis of McKusick-Kaufman syndrome (MKKS). However, additional features, including characteristic radiographic findings of the hands and a large hypothalamic tumour, presumably a hamartoma, favoured the diagnosis of Pallister-Hall syndrome (PHS), which was then genetically confirmed by detection of a GLI3 mutation (Q717X). This is the second genetically confirmed case revealing the previously described association of PHS with hydrometrocolpos due to vaginal atresia as a clinical overlap with MKKS.