However, the identification of only missense variants for Marbach-Schaaf neurodevelopmental syndrome and the abundant presence of loss-of-function variants (nonsense, frameshift, and splice variants) in the population database gnomAD (https://gnomad.broadinstitute.org/gene/ENSG00000188191) indicate that PRKAR1B is not haploinsufficient, consistent with its low statistical values for haploinsufficiency index and probability of loss-of-function intolerance (https://search.clinicalgenome.org/kb/genes/HGNC:9390). The gene discussed is PRKAR1B; the disease is Marbach-Schaaf neurodevelopmental syndrome.