Opitz-Kaveggia syndrome is a rare X-linked multiple congenital anomalies and intellectual disability disorder caused by the recurrent p.R961W mutation in the MED12 gene. Twenty-three affected males from 10 families with this mutation in the MED12 gene have been described so far. Here we report on a new family with three affected cousins, in which we identified a novel MED12 mutation (p.G958E). This is the first demonstration that other mutations in this gene can also lead to Opitz-Kaveggia syndrome. The clinical phenotype of these three new cases is reviewed in detail and compared with the previous reported cases.