Jozef Gécz is a human molecular geneticist internationally recognised for his contributions to the genetics of childhood onset neurological disorders, including intellectual disabilities, epilepsies, autisms and cerebral palsies. Gécz identified the first gene for non-syndromic intellectual disability, the FMR2 gene in 1994 and more than 100 other genes for various forms of neurodevelopmental disabilities. His research has transformed the understanding of the genetic architecture of neurodevelopmental disorders and those arising from genes on the human X chromosome specifically, and has led to better management and treatment of these conditions. His research delved into fundamental aspects of disease mechanisms and led, among others, to clinical trial of the neurosteroid allopregnanolone for treatment of PCDH19 girls-only epilepsy and autism.