Findings that are reminiscent of those observed in Gnasxl knockout mice and the mice with paternal Gnas exon 2 disruption have been reported in two unrelated children with large paternal deletions of chromosome 20q13.3 that comprise the GNAS locus [83]. These findings included perinatal growth retardation, intractable feeding difficulties, and loss of subcutaneous adiposity, as well as dysmorphic facial features. Because the deletion involved, in each case, the entire GNAS locus, it is possible that the phenotype reflects, at least partially, the deficiency of Gsα and/or the other paternally expressed GNAS products (see below).
