has material basis in germline mutation in CASK FG syndrome FG syndrome 4 https://github.com/monarch-initiative/mondo/issues/4521 https://github.com/monarch-initiative/mondo/issues/9747 https://rarediseases.info.nih.gov/diseases/9925/x-linked-intellectual-disability-with-or-without-nystagmus https://www.malacards.org/card/fg_syndrome_4 OMIM:300422 CASK-related FG syndrome MEDGEN:336965 FG syndrome 4 FG syndrome type 4 UMLS:C1845546 FG syndrome caused by mutation in cask MONDO:0010318 FGS4 mental retardation, X-linked, with or without Nystagmus cask FG syndrome Any FG syndrome in which the cause of the disease is a mutation in the CASK gene. CASK FG syndrome CASK-related intellectual disability