Editor’s note 2/6/2013: Pending an FDA decision, 23andMe no longer offers new customers access to health reports referred to in this post. Customers who received their health information prior to November 22, 2013 will still be able to see their health reports, but those who purchased after that time will only have access to ancestry information as well as access to their uninterpreted raw data. These new customers may receive health reports in the future dependent on FDA marketing authorization.
By Alison Chubb
We’ve all known teenagers who grow several inches in a year, and then start bumping into people and furniture as they figure out what to do with their big feet and long arms. The growth spurt that happens during adolescence can account for up to 20 percent of one’s final height, and we know that genetics is largely responsible for why kids grow less or more, during that time. But until now, we didn’t know much about the genetic variants involved in this sometimes awkward phase of childhood growth.
Recently, researchers from the Early Growth Genetics Consortium analyzed growth data from over 10,000 people of European descent looking for genes relevant to childhood growth rates. They found genetic variants linked to height and growth during adolescence and published their results in the journal Human Molecular Genetics.
The single-nucleotide polymorphism (SNP) rs7759938 was associated with late adolescent growth. People with the C version of this SNP tended to grow slightly more between the ages of 14 and 18 compared to people without the C version. This SNP is located near LIN28B, a gene linked to height in adulthood and age at menarche (first period).
Another SNP, rs1172294, was associated with overall adolescent growth. People with the A version of this SNP tended to grow slightly more between the ages of eight and 18, while those with the G version tended to grow slightly less. The researchers also discovered that women with the G version of rs1172294 experienced their first period at a slightly earlier age, on average. This marker is located near ADCY3 and POMC, two genes implicated in childhood and adult obesity. ADCY3 is an enzyme important for communication between cells throughout the body, and POMC is expressed in the pituitary gland that releases several hormones important for growth.
We know from epidemiological studies that obesity during childhood is linked to earlier puberty, and that earlier puberty raises the risk for obesity and possibly other health conditions in adults. This new study is interesting because it shows that some of the genetic factors underlying obesity and growth patterns in childhood may overlap, and that they may also influence risk for other diseases in adults, but much more research is needed to unravel these complicated genetic connections.