gatad2b-associated neurodevelopmental disorder gatad2b-associated neurodevelopmental disorder gatad2b-associated neurodevelopmental disorder is a rare genetic neurodevelopmental disorder which is characterized by severe intellectual disabilities, speech delays, hypotonia and facial dysmorphia. gatad2b-associated neurodevelopmental disorderother namesgandspecialtymedical geneticsusual onsetbirthdurationlife-longcausesmutation in the gatad2b gene.preventionnoneprognosismedium, nearing goodfrequencyvery rare, only 78 cases have been described in medical literaturedeaths- signs and symptoms the following is a list of all the symptoms: moderate to severe intellectual disabilities speech delay macrocephaly childhood low muscle tone feeding problems variable cardiac anomalies facial dysmorphisms additional symptoms include polyhydramnios and epilepsy. causes this condition is caused by either (usually sporadic or de novo) alterations or a deletion of the gatad2b gene, located in chromosome 1. in familial cases, inheritance is usually autosomal dominant. epidemiology 78 cases have been described in medical literature.