DOK7 and fetal akinesia deformation sequence: 4.2. Escobar Variant of Multiple Pterygium Syndrome (EVMPS, Escobar Syndrome) (CHRNG) and Lethal Form of Multiple Pterygium Syndrome (LMPS)/Fetal Akinesia Deformation Sequence (FADS) (CHRNA1, CHRND, MUSK, RAPSN, DOK7, and SLC18A3)