Without enough thyroid hormone, metabolism slows, making weight gain more likely. Even a thyroid functioning at the lower end of the normal range might cause weight gain. Treating hypothyroidism with medication may reverse some of the weight gain. If you have any concerns, seek medical advice.
1 Allele: a different version of a gene. 2  Dominant: a trait that is visible and can cover up other traits when there is more than one present. 3  Genotype: the genetic makeup of an organism, or the versions of a gene that an organism has. 4  Heterozygous: having two different versions of a gene.
Genetic variation is a term used to describe the variation in the DNA sequence in each of our genomes. Genetic variation is what makes us all unique, whether in terms of hair colour, skin colour or even the shape of our faces. There are lots of different mutations that can occur in our DNA.