Polar overdominance

Polar overdominance is a unique form of inheritance originally described in livestock, with relevant examples in humans[1] and mice being discovered shortly after.

This polarity is shown as differential phenotype is only present in one of the heterozygote configurations when the recessive allele is inherited in a parent of origin type fashion.

After researching it was discovered that the two regions were likely unrelated due to different forms of parental inheritance exhibited in both cases and a relatively large physical distance between the loci on the chromosome.

[8] The term polar is used to describe this type of inheritance because the phenotype of one heterozygote is expressed at a level higher than other genotypes for the same locus including those displaying either homozygous geneotype.

[10] Individuals who inherit this mutant allele from their father are more likely to show signs of obesity because the DLK1 gene is key in adipogenesis, or more simply the formation of fat cells.