Familial periventricular nodular heterotopia, epilepsy and Melnick-Needles Syndrome caused by a single FLNA mutation with combined gain-of-function and loss-of-function effects.

Loss-of-function mutations of the FLNA gene cause a neuronal migration disorder defined as X-linked periventricular nodular heterotopia (PNH); gain-of-function mutations are associated with a group of X-linked skeletal dysplasias designed as otopalatodigital (OPD) spectrum. We describe a family in which a woman and her three daughters exhibited a complex phenotype combining PNH, epilepsy and Melnick-Needles syndrome (MNS), a skeletal disorder assigned to the OPD spectrum. All four individuals harboured a novel non-conservative missense mutation in FLNA exon 3.