Clinical
Recently, several heterozygous missense human NOG mutations in unrelated families with proximal symphalangism (SYM1) and multiple synostoses syndrome (SYNS1) have been identified; both SYM1 and SYNS1 have multiple joint fusion as their principal feature, and map to the same region on chromosome 17 (17q22) as NOG. These mutations indicate functional haploinsufficiency where the homozygous forms are embryonically lethal.
All these NOG mutations have altered evolutionarily conserved amino acid residues.
Read more about this topic: Noggin (protein)