Demystifying the Genetics of Eating Disorders – Part II

In my last post I talked about some methods that scientists use to study the genetics of eating disorders. I focused on a subfield of genetics called behavioural genetics (which you can think of as a field that attempts to understand, in part, the interplay of genetics and environment in behaviour). In this post I’ll shift gears and focus on molecular genetics. I’ll be working of the same review paper by Drs. Zerwas and Bulik (2011). Molecular geneticists study the structure and function of genes on a molecular level. For example, they try to understand how different mutations or alterations in the genetic code can affect protein function and lead to disease states.

GENETIC ASSOCIATION STUDIES

Genetic association studies are hypothesis driven. This means that researchers make a list of genes that are known to be involved in biological mechanisms or behaviours that are affected in eating disorders, such … Continue reading →

Endophenotypes and Biomarkers in Eating Disorders: Genetic Underpinnings, Personality Traits, Vulnerabilities – Part 2

This post continues the discussion of the chapter on eating disorders by Carolina Lopez, Marion Roberts, and Janet Treasure from The Handbook of Neuropsychiatric Biomarkers, Endophenotypes and Genes (2009). Part 1 focused on neurotransmitter biomarkers, and this second part will focus on the neuropsychological biomarkers.

NEUROPSYCHOLOGICAL BIOMARKERS

Attentional biases

Attentional bias is the tendency for individuals to attend to or be distracted by emotionally relevant stimuli over neutral stimuli. Attentional biases have been observed in several studies:

  • Current AN and BN individuals showed bias towards food, body-related stimuli.
  • Past AN but not past BN showed bias towards body shape concerns.
  • Both current and “long-term recovered” AN showed “abnormally higher activation in the medial prefrontal and anterior cingulate cortices in response to food stimuli using fMRI [brain imaging]” (232)

These biases can be minimal but annoying: waiting in line at the pharmacy, staring into space and finding your focus … Continue reading →

Endophenotypes and Biomarkers in Eating Disorders: Genetic Underpinnings, Personality Traits, Vulnerabilities – Part 1

There have been some interesting discussions on the F.E.A.S.T. Facebook group over the past month regarding the role of genetics, personality traits, environmental factors and their role (or lack thereof) in the development of eating disorders and their prognosis. A parent group may seem like an unlikely forum for several hundred-odd comment threads on etiology; however, what we (caregivers, patients or clinicians) believe to underlie these disorders naturally informs our attitudes, decisions and choices with regards to treatment and our relationship to the disorders themselves:

Is this something they will have to manage their entire life?
Does anyone ever fully recover?
I had bulimia as a young adult and now my son has an eating disorder, too – did I pass on “bad genes”, bad habits, or is it a coincidence?
Is her rigidity and anxiety merely a side affect of starvation, or should we treat those as
Continue reading →