"Function mutations" refers to changes or alterations that occur in the genetic code or DNA sequence, which can lead to changes in how a specific protein or biological function is performed or carried out within a living organism. Full definition
Loss of function mutations in human Oligophrenin1 (OPHN1) gene are responsible for syndromic intellectual disability (ID) associated with cerebellar hypoplasia and cerebral ventricles enlargement. (inb.u-bordeaux2.fr)
Of the genotyped Icelanders, 7.7 % are homozygotes or compound heterozygotes for loss - of - function mutations with a minor allele frequency (MAF) below 2 % in 1,171 genes (complete knockouts). (nature.com)
The first is that the Mstn loss - of - function mutation exerts a maternal effect such that muscle mass of the fetus is influenced by the number of functional Mstn alleles in the mother. (journals.plos.org)