ANOREXIA AND BULIMIA GENETIC 2007----1974 ANOREXIA PARENTS MUCH OLDER

Genetic Risk Factors For Eating Disorders Discovered
Science Daily — Until recently, it was generally believed that eating disorders such as anorexia nervosa and bulimia nervosa resulted solely from environmental influences such as peer pressure and certain perceived expectations of society.
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But research at Michigan State University has found that there are genetic risk factors at work as well. The research of Kelly Klump, an MSU associate professor of psychology, published in the May issue of Psychological Medicine, indicates that the origin of eating disorders has biological roots, similar to how bipolar disorder and schizophrenia are thought to have biological causes.

Specifically, Klump’s work found that when girls enter puberty their chances of developing such a disease grow rapidly.

“During puberty, there is an increased risk for developing an eating disorder,” said Klump. “Up to 50 percent of this risk can be attributed to genetic factors that emerge during puberty.”

Klump’s research looked at more than 500 female 14-year-old twins who were examined using sophisticated statistical modeling techniques. It was found that before puberty, environmental factors alone contribute to the development of various eating disorders. As puberty progresses, the genetic risk is activated and increases in importance to accounting for more than half the risk for eating pathology.

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Psychosomatic Medicine Vol. 36, No. 1 (Jan.-Feb. 1974)
Anorexia Nervosa:
Demographic and Clinical Features in 94 Cases
KATHERINE A. HALMI, MD
A comprehensive chart study was made of numerous clinical and demographic features in 94
patients with anorexia nervosa. Unlike other large series, this survey included the pediatric age
group. A significantly greater maternal and paternal age at time of the patient's birth and a
greater incidence of both low and high birth weights compared with the general population was
found. A relatively high occurrence of premorbid feeding problems was present. Anxiety and
obsessive-compulsive traits were frequent premorbid symptoms. Precipitating events were
identified more frequently in patients with a greater age at onset of illness. Characteristic
behavior noted during the course of this illness is described.




The mothers' age at time of the patients'
birth was significantly greater (p < .001,
Kolmogorov-Smirnov goodness fit test)
than that for national control mothers (14)
or Iowa control mothers2 (Fig. 1). Also,
the fathers' age at the time of the patients'
birth was significantly greater (p < .05,
Kolmogorov-Smirnov goodness-of-fit test)
than that of national control fathers (15)
(Fig. 2). A significantly higher mothers'
age at the time of probands' birth compared
to that of Swedish control mothers
was also reported by Theander (1). Kay
and Leigh (11) did not analyze their data
statistically, but nonetheless stated that
youthfulness or advanced age of mothers
at the patients' birth appeared unimportant.


SUMMARY
Significant demographic characteristics
found in this survey of the hospital
records of 94 anorexia patients include a
greater maternal and paternal age at time
of the probands' birth and a greater
incidence of both low and high birth
weights than in the general population.
Unlike other large series of anorexia
nervosa patients, this survey included the
pediatric age group. This would explain
the relatively high incidence, 8%, of onset
of illness prior to age 10.