Objective
To describe obstacles in the implementation of a controlled treatment trial of adolescent anorexia nervosa (AN).
Method
The original aim was to enter 240 participants with AN to one of 4 cells: Behavioral family therapy (BFT) plus fluoxetine; BFT plus placebo; systems family therapy (SFT) plus fluoxetine; SFT plus placebo.
Results
Recruitment was delayed pending a satisfactory resolution concerning participant safety. After 6 months of recruitment it became clear that the medication was associated with poor recruitment leading to a study redesign resulting in a comparison of two types of family therapy with a projected sample size of 160. One site was unable to recruit and was replaced.
Discussion
Problems with the delineation of safety procedures, recruitment, re-design of the study, and replacement of a site, were the main elements resulting in a 1-year delay. Suggestions are made for overcoming such problems in future AN trials.
doi:10.1002/eat.20923
PMCID: PMC3140589
PMID: 21495052
Anorexia nervosa; adolescents; Behavioral Family Therapy; Systems Family Therapy; RIAN trial
Dellava, Jocilyn E. | Trace, Sara E. | Strober, Michael | Thornton, Laura M. | Klump, Kelly L. | Brandt, Harry | Crawford, Steve | Fichter, Manfred M. | Halmi, Katherine A. | Johnson, Craig | Kaplan, Allan S. | Mitchell, James E. | Treasure, Janet | Woodside, D. Blake | Berrettini, Wade H. | Kaye, Walter H. | Bulik, Cynthia M.
This exploratory study assessed whether maternal recall of childhood feeding and eating practices differed across anorexia nervosa (AN) subtypes. Participants were 325 women from the Genetics of Anorexia Nervosa study whose mothers completed a childhood feeding and eating questionnaire. Multinomial logistic regression analyses were used to predict AN subtype from measures related to childhood eating: (a) infant feeding (breastfed, feeding schedule, age of solid food introduction), (b) childhood picky eating (picky eating before age one and between ages one and five), and (c) infant gastrointestinal problems (vomiting and colic). Results revealed no significant differences in retrospective maternal report of childhood feeding and eating practices among AN subtypes.
doi:10.1002/erv.1153
PMCID: PMC3391535
PMID: 21830261
Anorexia Nervosa; Anorexia Nervosa Subtype; Feeding; Maternal Report; Infancy
Bloss, Cinnamon S | Berrettini, Wade | Bergen, Andrew W | Magistretti, Pierre | Duvvuri, Vikas | Strober, Michael | Brandt, Harry | Crawford, Steve | Crow, Scott | Fichter, Manfred M | Halmi, Katherine A | Johnson, Craig | Kaplan, Allan S | Keel, Pamela | Klump, Kelly L | Mitchell, James | Treasure, Janet | Woodside, D Blake | Marzola, Enrica | Schork, Nicholas J | Kaye, Walter H
Follow-up studies of eating disorders (EDs) suggest outcomes ranging from recovery to chronic illness or death, but predictors of outcome have not been consistently identified. We tested 5151 single-nucleotide polymorphisms (SNPs) in approximately 350 candidate genes for association with recovery from ED in 1878 women. Initial analyses focused on a strictly defined discovery cohort of women who were over age 25 years, carried a lifetime diagnosis of an ED, and for whom data were available regarding the presence (n=361 ongoing symptoms in the past year, ie, ‘ill') or absence (n=115 no symptoms in the past year, ie, ‘recovered') of ED symptoms. An intronic SNP (rs17536211) in GABRG1 showed the strongest statistical evidence of association (p=4.63 × 10−6, false discovery rate (FDR)=0.021, odds ratio (OR)=0.46). We replicated these findings in a more liberally defined cohort of women age 25 years or younger (n=464 ill, n=107 recovered; p=0.0336, OR=0.68; combined sample p=4.57 × 10−6, FDR=0.0049, OR=0.55). Enrichment analyses revealed that GABA (γ-aminobutyric acid) SNPs were over-represented among SNPs associated at p<0.05 in both the discovery (Z=3.64, p=0.0003) and combined cohorts (Z=2.07, p=0.0388). In follow-up phenomic association analyses with a third independent cohort (n=154 ED cases, n=677 controls), rs17536211 was associated with trait anxiety (p=0.049), suggesting a possible mechanism through which this variant may influence ED outcome. These findings could provide new insights into the development of more effective interventions for the most treatment-resistant patients.
doi:10.1038/npp.2011.108
PMCID: PMC3176559
PMID: 21750581
GABA; anorexia nervosa; recovery from eating disorders; genetic association; single nucleotide polymorphisms; eating/metabolic disorders; GABA; eating/metabolic disorders; neurogenetics; biological psychiatry; genetic association; anorexia nervosa; recovery from eating disorders; single-nucleotide polymorphisms; phenomic association
Reyes-Rodríguez, Mae Lynn | Von Holle, Ann | Ulman, T. Frances | Thornton, Laura M. | Klump, Kelly L. | Brandt, Harry | Crawford, Steve | Fichter, Manfred M. | Halmi, Katherine A. | Huber, Thomas | Johnson, Craig | Jones, Ian | Kaplan, Allan S. | Mitchell, James E. | Strober, Michael | Treasure, Janet | Woodside, D. Blake | Berrettini, Wade H. | Kaye, Walter H. | Bulik, Cynthia M.
Objective
Comorbidity among eating disorders, traumatic events, and post traumatic stress disorder (PTSD) has been reported in several studies. The main objectives of this study were to describe the nature of traumatic events experienced and to explore the relation between PTSD and anorexia nervosa (AN) in a sample of women.
Methods
Eight hundred twenty-four participants from the National Institutes of Health funded Genetics of Anorexia Nervosa Collaborative Study were assessed for eating disorders, PTSD, and personality characteristics.
Results
From a final sample of 753 women with AN, 13.7% (n=103) met DSM-IV criteria for PTSD. The sample mean age was 29.5 years (SD=11.1). In pairwise comparisons across AN subtypes, the odds of having a PTSD diagnosis were significantly lower in individuals with restricting AN (RAN) than individuals with purging AN without binge eating (PAN) (OR=0.49, 95% CI=0.30, 0.80). The majority of participants with PTSD reported the first traumatic event before the onset of AN (64.1%, n=66). The most common traumatic events reported by those with a PTSD diagnosis were sexual related traumas during childhood (40.8%) and during adulthood (35.0%).
Conclusions
AN and PTSD do co-occur and traumatic events tend to occur prior to the onset of AN. Clinically, these results underscore the importance of assessing trauma history and PTSD in individuals with AN and raise the question of whether specific modifications or augmentations to standard treatment for AN should be considered in a subgroup to address PTSD-related psychopathology.
doi:10.1097/PSY.0b013e31822232bb
PMCID: PMC3132652
PMID: 21715295
PTSD; anorexia nervosa; trauma; prevalence; comorbid; epigenetic
Root, Tammy L. | Szatkiewicz, Jin P. | Jonassaint, Charles R. | Thornton, Laura M. | Pinheiro, Andrea Poyastro | Strober, Michael | Bloss, Cinnamon | Berrettini, Wade | Schork, Nicholas J. | Kaye, Walter H. | Bergen, Andrew W. | Magistretti, Pierre | Brandt, Harry | Crawford, Steve | Crow, Scott | Fichter, Manfred M. | Goldman, David | Halmi, Katherine A. | Johnson, Craig | Kaplan, Allan S. | Keel, Pamela K. | Klump, Kelly L. | La Via, Maria | Mitchell, James E. | Rotondo, Alessandro | Treasure, Janet | Woodside, D. Blake | Bulik, Cynthia M.
This analysis is a follow-up to an earlier investigation of 182 genes selected as likely candidate genetic variations conferring susceptibility to anorexia nervosa (AN). As those initial case-control results revealed no statistically significant differences in single nucleotide polymorphisms, herein we investigate alternative phenotypes associated with AN. In 1762 females using regression analyses we examined: (1) lowest illness-related attained body mass index; (2) age at menarche; (3) drive for thinness; (4) body dissatisfaction; (5) trait anxiety; (6) concern over mistakes; and (7) the anticipatory worry and pessimism vs. uninhibited optimism subscale of the harm avoidance scale. After controlling for multiple comparisons, no statistically significant results emerged. Although results must be viewed in the context of limitations of statistical power, the approach illustrates a means of potentially identifying genetic variants conferring susceptibility to AN because less complex phenotypes associated with AN are more proximal to the genotype and may be influenced by fewer genes.
doi:10.1002/erv.1138
PMCID: PMC3261131
PMID: 21780254
covariates; eating disorders; association studies; personality; genetic
Jonassaint, Charles R. | Szatkiewicz, Jin Peng | Bulik, Cynthia M. | Thornton, Laura M. | Bloss, Cinnamon | Berrettini, Wade | Kaye, Walter H. | Bergen, Andrew W. | Magistretti, Pierre | Strober, Michael | Keel, Pamela K. | Brandt, Harry | Crawford, Steve | Crow, Scott | Fichter, Manfred M. | Goldman, David | Halmi, Katherine A. | Johnson, Craig | Kaplan, Allan S. | Klump, Kelly L. | La Via, Maria | Mitchell, James | Rotondo, Alessandro | Treasure, Janet | Woodside, D. Blake
Extensive population-based genome-wide association studies have identified an association between the FTO gene and BMI; however, the mechanism of action is still unknown. To determine whether FTO may influence weight regulation through psychological and behavioral factors, seven single nucleotide polymorphisms (SNPs) of the FTO gene were genotyped in 1085 individuals with anorexia nervosa (AN) and 677 healthy weight controls from the international Price Foundation Genetic Studies of Eating Disorders. Each SNP was tested in association with eating disorder phenotypes and measures that have previously been associated with eating behavior pathology: trait anxiety, harm-avoidance, novelty seeking, impulsivity, obsessionality, compulsivity, and concern over mistakes. After appropriate correction for multiple comparisons, no significant associations between individual FTO gene SNPs and eating disorder phenotypes or related eating behavior pathology were identified in cases or controls. Thus, this study found no evidence that FTO gene variants associated with weight regulation in the general population are associated with eating disorder phenotypes in AN participants or matched controls.
doi:10.1002/ajmg.b.31182
PMCID: PMC3249222
PMID: 21438147
Maxwell, Millie | Thornton, Laura M. | Root, Tammy L. | Pinheiro, Andrea Poyastro | Strober, Michael | Brandt, Harry | Crawford, Steve | Crow, Scott | Fichter, Manfred M. | Halmi, Katherine A. | Johnson, Craig | Kaplan, Allan S. | Keel, Pamela | Klump, Kelly L. | LaVia, Maria | Mitchell, James E. | Plotnicov, Kathy | Rotondo, Alessandro | Woodside, D. Blake | Berrettini, Wade H. | Kaye, Walter H. | Bulik, Cynthia M.
Objective
We investigated sociodemographic characteristics in women with and without lifetime eating disorders.
Method
Participants were from a multi-site international study of eating disorders (N = 2096). Education level, relationship status, and reproductive status were examined across eating disorder subtypes and compared with a healthy control group.
Results
Overall, women with eating disorders were less educated than controls, and duration of illness and age of onset were associated with educational attainment. Menstrual status was associated with both relationship and reproductive status, but eating disorder subtypes did not differ significantly from each other or from healthy controls on these dimensions.
Conclusion
Differences in educational attainment, relationships, and reproduction do exist in individuals with eating disorders and are differentially associated with various eating disorder symptoms and characteristics. These data could assist with educating patients and family members about long-term consequences of eating disorders.
doi:10.1002/eat.20804
PMCID: PMC2888627
PMID: 20143323
Children; relationship; education; anorexia nervosa; bulimia nervosa; amenorrhea
Background
This study compared the best available treatment for bulimia nervosa,
cognitive–behavioural therapy (CBT) augmented by fluoxetine if
indicated, with a stepped-care treatment approach in order to enhance
treatment effectiveness.
Aims
To establish the relative effectiveness of these two approaches.
Method
This was a randomised trial conducted at four clinical centres
(Clinicaltrials.gov
registration number: NCT00733525). A total of 293 participants with bulimia
nervosa were randomised to one of two treatment conditions: manual-based CBT
delivered in an individual therapy format involving 20 sessions over 18 weeks
and participants who were predicted to be non-responders after 6 sessions of
CBT had fluoxetine added to treatment; or a stepped-care approach that began
with supervised self-help, with the addition of fluoxetine in participants who
were predicted to be non-responders after six sessions, followed by CBT for
those who failed to achieve abstinence with self-help and medication
management.
Results
Both in the intent-to-treat and completer samples, there were no
differences between the two treatment conditions in inducing recovery (no
binge eating or purging behaviours for 28 days) or remission (no longer
meeting DSM–IV criteria). At the end of 1-year follow-up, the
stepped-care condition was significantly superior to CBT.
Conclusions
Therapist-assisted self-help was an effective first-level treatment in the
stepped-care sequence, and the full sequence was more effective than CBT
suggesting that treatment is enhanced with a more individualised approach.
doi:10.1192/bjp.bp.110.082172
PMCID: PMC3093678
PMID: 21415046
Pinheiro, Andréa Poyastro | Raney, TJ | Thornton, Laura M. | Fichter, Manfred M. | Berrettini, Wade H. | Goldman, David | Halmi, Katherine A. | Kaplan, Allan S. | Strober, Michael | Treasure, Janet | Woodside, D. Blake | Kaye, Walter H. | Bulik, Cynthia M.
Objective
To describe sexual functioning in women with eating disorders.
Method
We assessed physical intimacy, libido, sexual anxiety, partner and sexual relationships in 242 women from the International Price Foundation Genetic Studies relative to normative data.
Results
Intercourse (55.3%), having a partner (52.7%), decreased sexual desire (66.9%), and increased sexual anxiety (59.2%) were common. Women with restricting and purging anorexia nervosa had a higher prevalence of loss of libido than women with bulimia nervosa and eating disorder not otherwise specified (75%, 74.6%, 39% and 45.4%, respectively). Absence of sexual relationships was associated with lower minimum lifetime body mass index (BMI) and earlier age of onset; loss of libido with lower lifetime BMI, higher interoceptive awareness and trait anxiety; and sexual anxiety with lower lifetime BMI, higher harm avoidance and ineffectiveness. Sexual dysfunction in eating disorders was higher than in the normative sample.
Conclusion
Sexual dysfunction is common across eating disorders subtypes. Low BMI is associated with loss of libido, sexual anxiety, and avoidance of sexual relationships.
doi:10.1002/eat.20671
PMCID: PMC2820601
PMID: 19260036
anorexia nervosa; eating disorders; sexual behavior; sexual dysfunction
Root, Tammy | Pinheiro, Andréa Poyastro | Thornton, Laura | Strober, Michael | Fernandez-Aranda, Fernando | Brandt, Harry | Crawford, Steve | Fichter, Manfred M. | Halmi, Katherine A. | Johnson, Craig | Kaplan, Allan S. | Klump, Kelly L. | La Via, Maria | Mitchell, James | Woodside, D. Blake | Rotondo, Alessandro | Berrettini, Wade H. | Kaye, Walter H. | Bulik, Cynthia M.
Objective
We examined prevalence of substance use disorders (SUD) in women with: (1) anorexia nervosa (AN) restricting type (RAN); (2) AN with purging only (PAN); (3) AN with binge eating only (BAN); and (4) lifetime AN and bulimia nervosa (ANBN). Secondary analyses examined SUD related to lifetime purging behavior and lifetime binge eating.
Method
Participants (N = 731) were drawn from the International Price Foundation Genetic Studies.
Results
The prevalence of SUD differed across AN subtypes, with more in the ANBN group reporting SUD than those in the RAN and PAN groups. Individuals who purged were more likely to report substance use than those who did not purge. Prevalence of SUD differed across lifetime binge eating status.
Conclusion
SUD are common in AN and are associated with bulimic symptomatology. Results underscore the heterogeneity in AN, highlighting the importance of screening for SUD across AN subtypes.
doi:10.1002/eat.20670
PMCID: PMC2807480
PMID: 19260043
eating disorders; anorexia nervosa; bulimia nervosa; drug use; alcohol related disorders; cannabis
Dellava, Jocilyn E. | Thornton, Laura M. | Hamer, Robert M. | Strober, Michael | Plotnicov, Katherine | Klump, Kelly L. | Brandt, Harry | Crawford, Steve | Fichter, Manfred M. | Halmi, Katherine A. | Jones, Ian | Johnson, Craig | Kaplan, Allan S. | LaVia, Maria | Mitchell, James | Rotondo, Alessandro | Treasure, Janet | Woodside, D. Blake | Berrettini, Wade H. | Kaye, Walter H. | Bulik, Cynthia M.
Objective
Extremely low body mass index (BMI) values are associated with increased risk for death and poor long-term prognosis in individuals with AN. The present study explores childhood personality characteristics that could be associated with the ability to attain an extremely low BMI.
Methods
Participants were 326 women from the Genetics of Anorexia Nervosa (GAN) Study who completed the Structured Interview for Anorexia Nervosa and Bulimic Syndromes and whose mother completed the Child Behavioral Check List and/or Revised Dimensions of Temperament Survey.
Results
Children who were described as having greater fear or anxiety by their mothers attained lower BMIs during AN (p <0.02). Path analysis in the GAN and a validation sample, Price Foundation Anorexia Nervosa Trios Study, confirmed the relation between early childhood anxiety, caloric restriction, qualitative food item restriction, excessive exercise, and low BMI. Path analysis also confirmed a relation between childhood anxiety and caloric restriction, which mediated the relation between childhood anxiety and low BMI in the GAN sample only.
Conclusion
Fearful or anxious behavior as a child was associated with the attainment of low BMI in AN and childhood anxiety was associated with caloric restriction. Measures of anxiety and factors associated with anxiety-proneness in childhood may index children at risk for restrictive behaviors and extremely low BMIs in AN.
doi:10.1016/j.brat.2009.09.009
PMCID: PMC2812624
PMID: 19822312
Anorexia Nervosa; Anxiety; Body Mass Index
Pinheiro, Andrea Poyastro | Bulik, Cynthia M. | Thornton, Laura M. | Sullivan, Patrick F. | Root, Tammy L. | Bloss, Cinnamon S. | Berrettini, Wade H. | Schork, Nicholas J. | Kaye, Walter H. | Bergen, Andrew W. | Magistretti, Pierre | Brandt, Harry | Crawford, Steve | Crow, Scott | Fichter, Manfred M. | Goldman, David | Halmi, Katherine A. | Johnson, Craig | Kaplan, Allan S. | Keel, Pamela K. | Klump, Kelly L. | La Via, Maria | Mitchell, James E. | Strober, Michael | Rotondo, Alessandro | Treasure, Janet | Woodside, D. Blake
We performed association studies with 5,151 SNPs that were judged as likely candidate genetic variations conferring susceptibility to anorexia nervosa (AN) based on location under reported linkage peaks, previous results in the literature (182 candidate genes), brain expression, biological plausibility, and estrogen responsivity. We employed a case–control design that tested each SNP individually as well as haplotypes derived from these SNPs in 1,085 case individuals with AN diagnoses and 677 control individuals. We also performed separate association analyses using three increasingly restrictive case definitions for AN: all individuals with any subtype of AN (All AN: n = 1,085); individuals with AN with no binge eating behavior (AN with No Binge Eating: n = 687); and individuals with the restricting subtype of AN (Restricting AN: n = 421). After accounting for multiple comparisons, there were no statistically significant associations for any individual SNP or haplotype block with any definition of illness. These results underscore the importance of large samples to yield appropriate power to detect genotypic differences in individuals with AN and also motivate complementary approaches involving Genome-Wide Association (GWA) studies, Copy Number Variation (CNV) analyses, sequencing-based rare variant discovery assays, and pathway-based analysis in order to make up for deficiencies in traditional candidate gene approaches to AN.
doi:10.1002/ajmg.b.31082
PMCID: PMC2963154
PMID: 20468064
single nucleotide polymorphisms; probands; anorexia nervosa; bulimia nervosa
Objective
To examine the course of Eating Disorder NOS (EDNOS) compared with anorexia nervosa (AN), bulimia nervosa (BN) and binge eating disorder (BED).
Method
Prospective study of 385 participants meeting DSM-IV criteria for AN, BN, BED and EDNOS at 3 sites. Recruitment was from the community and specialty clinics. Participants were followed at 6-month intervals over a 4-year period using the Eating Disorder Examination as the primary assessment.
Results
EDNOS remitted significantly more quickly that AN or BN but not BED. There were no differences between EDNOS and full ED syndromes, or the sub-types of EDNOS, in time to relapse following first remission. Only 18% of the EDNOS group had never had or did not develop another ED diagnosis during the study, however this group did not differ from the remaining EDNOS group.
Conclusion
EDNOS appears to be a way station between full ED syndromes and recovery, and to a lesser extent from recovery or EDNOS status to a full ED. Implications for DSM-V are examined.
doi:10.1002/eat.20708
PMCID: PMC2862563
PMID: 19544557
Information from eating disorder clinics across five continents suggests that anorexia nervosa is becoming an increasing problem in children and young adolescents. There is some indication that anxiety disorders in childhood may be a major risk factor for the development of anorexia nervosa. Early recognition and family treatment for this disorder are essential to prevent chronic impairment.
PMCID: PMC3181903
PMID: 19432392
anorexia nervosa; body image; dieting; perfectionism; biological vulnerability
Reba-Harrelson, Lauren | Von Holle, Ann | Thornton, Laura M. | Klump, Kelly L. | Berrettini, Wade H. | Brandt, Harry | Crawford, Steven | Crow, Scott | Fichter, Manfred M. | Goldman, David | Halmi, Katherine A. | Johnson, Craig | Kaplan, Allan S. | Keel, Pamela | LaVia, Maria | Mitchell, James | Plotnicov, Katherine | Rotondo, Alessandro | Strober, Michael | Treasure, Janet | Woodside, D. Blake | Kaye, Walter H. | Bulik, Cynthia M.
We investigated the relation between diet pill use and eating disorder subtype, purging and other compensatory behaviors, body mass index (BMI), tobacco and caffeine use, alcohol abuse or dependence, personality characteristics, and Axis I and Axis II disorders in 1,345 participants from the multisite Price Foundation Genetics Studies. Diet pill use was significantly less common in women with restricting type of AN than in women with other eating disorder subtypes. In addition, diet pill use was associated with the use of multiple weight control behaviors, higher BMI, higher novelty seeking, and the presence of anxiety disorders, alcohol abuse or dependence, and borderline personality disorder. Findings suggest that certain clinical and personality variables distinguish individuals with eating disorders who use diet pills from those who do not. In the eating disorder population, vigilant screening for diet pill use should be routine clinical practice.
doi:10.1016/j.eatbeh.2007.04.001
PMCID: PMC2248697
PMID: 18167325
Eating disorders; diet pills; weight control behaviors; novelty seeking
Bacanu, Silviu-Alin | Bulik, Cynthia M. | Klump, Kelly L. | Fichter, Manfred M. | Halmi, Katherine A. | Keel, Pamela | Kaplan, Alan S. | Mitchell, James E. | Rotondo, Alessandro | Strober, Michael | Treasure, Janet | Woodside, D. Blake | Sonpar, Vibhor A. | Xie, Weiting | Bergen, Andrew W. | Berrettini, Wade H. | Kaye, Walter H. | Devlin, Bernie
To increase the likelihood of finding genetic variation conferring liability to eating disorders, we measured over 100 attributes thought to be related to liability to eating disorders on affected individuals from multiplex families and two cohorts: one recruited through a proband with anorexia nervosa (AN; AN cohort); the other recruited through a proband with bulimia nervosa (BN; BN cohort). By a multilayer decision process based on expert evaluation and statistical analysis, six traits were selected for linkage analysis (1): obsessionality (OBS), age at menarche (MENAR) and anxiety (ANX) for quantitative trait locus (QTL) linkage analysis; and lifetime minimum Body Mass Index (BMI), concern over mistakes (CM) and food-related obsessions (OBF) for covariate-based linkage analysis. The BN cohort produced the largest linkage signals: for QTL linkage analysis, four suggestive signals: (for MENAR, at 10p13; for ANX, at 1q31.1, 4q35.2, and 8q13.1); for covariate-based linkage analyses, both significant and suggestive linkages (for BMI, one significant [4q21.1] and three suggestive [3p23, 10p13, 5p15.3]; for CM, two significant [16p13.3, 14q21.1] and three suggestive [4p15.33, 8q11.23, 10p11.21]; and for OBF, one significant [14q21.1] and five suggestive [4p16.1, 10p13.1, 8q11.23, 16p13.3, 18p11.31]). Results from the AN cohort were far less compelling: for QTL linkage analysis, two suggestive signals (for OBS at 6q21 and for ANX at 9p21.3); for covariate-based linkage analysis, five suggestive signals (for BMI at 4q13.1, for CM at 11p11.2 and 17q25.1, and for OBF at 17q25.1 and 15q26.2). Overlap between the two cohorts was minimal for substantial linkage signals.
doi:10.1002/ajmg.b.30226
PMCID: PMC2590774
PMID: 16152574
Complex disease; endophenotype; liability; mixture model; regression
Bulik, Cynthia M. | Bacanu, Silviu-Alin | Klump, Kelly L. | Fichter, Manfred M. | Halmi, Katherine A. | Keel, Pamela | Kaplan, Alan S. | Mitchell, James E. | Rotondo, Alessandro | Strober, Michael | Treasure, Janet | Woodside, D. Blake | Sonpar, Vibhor A. | Xie, Weiting | Bergen, Andrew W. | Berrettini, Wade H. | Kaye, Walter H. | Devlin, Bernie
Vulnerability to anorexia nervosa (AN) and bulimia nervosa (BN) arise from the interplay of genetic and environmental factors. To explore the genetic contribution, we measured over 100 psychiatric, personality and temperament phenotypes of individuals with eating disorders from 154 multiplex families accessed through an AN proband (AN cohort) and 244 multiplex families accessed through a BN proband (BN cohort). To select a parsimonious subset of these attributes for linkage analysis, we subjected the variables to a multilayer decision process based on expert evaluation and statistical analysis. Criteria for trait choice included relevance to eating disorders pathology, published evidence for heritability, and results from our data. Based on these criteria, we chose six traits to analyze for linkage. Obsessionality, Age-at-Menarche, and a composite Anxiety measure displayed features of heritable quantitative traits, such as normal distribution and familial correlation, and thus appeared ideal for quantitative trait locus (QTL) linkage analysis. By contrast, some families showed highly concordant and extreme values for three variables — lifetime minimum Body Mass Index (lowest BMI attained during the course of illness), concern over mistakes, and food-related obsessions — whereas others did not. These distributions are consistent with a mixture of populations, and thus the variables were matched with covariate linkage analysis. Linkage results appear in a subsequent report. Our report lays out a systematic roadmap for utilizing a rich set of phenotypes for genetic analyses, including the selection of linkage methods paired to those phenotypes.
doi:10.1002/ajmg.b.30227
PMCID: PMC2560991
PMID: 16152575
Complex disease; endophenotype; liability; clinical judgment; covariate selection; mixture model; regression