Comments on: Interactive Effects of Genetics on Depression

By: Can You ‘Catch’ Depression?

Can You ‘Catch’ Depression? — Fri, 05 Jul 2013 11:18:44 +0000

[…] Interactive Effects of Genetics on Depression […]

By: Elizabeth Schaefer

Elizabeth Schaefer — Mon, 09 Jun 2008 16:42:34 +0000

Thanks for an interesting article. Despite the terminology issues noted above, your overall assertions — that we’re gaining ground on being able to identify genetically one’s susceptibility to depression in the face of stressors — is an important one.

There’s an additional, less-studied level of contol that may be at play too: epigenetics. Epigenetics looks at the expression (frequency of use) of genes as they are transcribed to make proteins. That is, other specific proteins may attach to the DNA, turning up and down the frequency at which it is transcribed into RNA to then make the proteins such as the serotonin transporter discussed in your article. I’m not aware of any research yet into the epigenetics of genes related to depression, but there’s an interesting article on epigenetics in general in the current Scientic American MIND.

Thanks for covering these topics.

By: Dan

Dan — Sat, 07 Jun 2008 10:29:09 +0000

SLC6A4 is the serotonin transporter gene, not an allele. The alleles you are referring to are the “s” and “l” alleles of the serotonin transporter’s promoter region (written as 5-HTTLPR). Each individual carries two versions of the allele, l/l, s/s or s/l. The s version of the allele is shorter than the l allele and it is the s allele that is linked to a variety of dysfunctions (because it is less effective than the l allele).

You use the terms “allele” and “gene” interchangeably, which is also incorrect, as an allele is a common variation in a gene, not a gene itself. When talking of SLC6A4 the term gene is the correct one. When talking about the part of the gene that varies, you want the acronym 5-HTTLPR (serotonin transporter gene promoter region).