De novo 2q+ masquerading as Smith-Lemli-Opitz syndrome.

We report a female infant diagnosed shortly after birth as having Smith-Lemli-Opitz syndrome. Despite previously reported normal G banded karyotypes, a high resolution banded chromosome analysis identified 46,XX,2q+. The importance of attention to established features of clinical syndromes, as well as persistence in investigation when diagnostic uncertainties exist, are discussed.