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J Hebebrand

Publications and source records attributed to J Hebebrand.

At least 55 records · Page 3Linked to original sources
PubMed2003

[Formal genetic findings in attention-deficit/hyperactivity-disorder].

Twin, family and adoption studies have led to a solid understanding of the contribution of both genetic and environmental factors to the development of attention deficit/hyperactivity disorder (ADHD). We review recent studies under consideration of both methodological aspects and relevant findings. Heritability estimates in the range of 0.6 - 0.8 surpass those for most other child and adolescent psychiatric disorders. First degree relatives have elevated rates for ADHD, affective disorders, conduct disorders and substance abuse and dependency. The ADHD subtype of the index patient does not predict the subtype of other family members affected with ADHD; hence non-genetic factors seemingly account for this intrafamilial variability. Because the familial rates for ADHD are not higher in families of female in comparison to male index patients, there is no indication that the genetic loading is higher in affected females. Recently, rater effects have been discussed broadly: Whereas the heritability estimates are uniformly high independent of the informant (mother, father, teacher), the correlations between quantitatively rated symptoms are low between different informants. Knowledge of the formal genetic aspects of ADHD is a prerequisite for understanding the results of recent molecular genetic studies.

Adolescent↗
PubMed2002

[Is topiramate effective for weight loss in neuroleptic-induced obesity? 2 case reports].

OBJECTIVES: Topiramate, a fairly new anticonvulsant, is increasingly being used as a mood stabilizer in bipolar and schizoaffective disorders. One common side effect is a reduced appetite that often results in weight loss. This finding raises the interesting question of whether both mood and body weight can be stabilized in patients who have gained weight while being treated with neuroleptics for one of the disorders mentioned above. METHODS: We studied the body weight, subjective sense of well-being, and psychopathology in two adolescent patients who were being treated with topiramate (alone or in combination with a neuroleptic drug). Both patients had reduced appetite, while body weight either remained stable or was reduced. RESULTS: The patients reported both improved control of food intake and mood stabilization. CONCLUSIONS: We conclude that adolescents with affective disturbance who have gained weight on neuroleptic drugs may benefit from topiramate in terms of mood stabilization and body weight control.

Adolescent↗
PubMed2002

Spousal resemblance in the Canadian population: implications for the obesity epidemic.

OBJECTIVE: To determine the extent of the spousal resemblance for adiposity and leanness in the Canadian population. DESIGN: Cross-sectional population survey. METHODS: The sample comprised parents and offspring from 1341 families (n=4023) of the Canada Fitness Survey. Indicators of adiposity included the body mass index (BMI) and the sum of five skinfolds (SF5). Both offspring and parents were ranked by their BMI and SF5 percentile position in the population using the entire Canada Fitness Survey database (n=15 818). RESULTS: Pearson correlations indicated significant spousal resemblance for both BMI (r=0.14; P<0.0001) and SF5 (r=0.13; P<0.0001). However, the magnitude of the spousal correlations varied by the adiposity status of the offspring, with spousal correlations tending to be stronger in parents of lean or obese children and lower among parents of 'average' children. Bivariate histograms indicated that among lean ( or=95th percentile), the parental pairs tended to cluster among the lower and higher percentiles of adiposity, respectively. CONCLUSIONS: There are spousal similarities in adiposity, particularly among parents of lean or obese offspring in the Canadian population. The degree to which these similarities are due to a loading of spouses with genes predisposing to obesity or a shared household environment cannot be determined from the present study. However, these results are compatible with the notion that genes and mutations predisposing to obesity are more prevalent among obese parents while those for pronounced leanness are more prevalent among lean parents.

Adolescent↗
PubMed2002

The 5-HT(2A) -1438G/A polymorphism in anorexia nervosa: a combined analysis of 316 trios from six European centres.

Several case-control association studies have raised the possibility that the A allele of a -1438 G/A polymorphism in the type 2A serotonin receptor (HTR2A) gene may be a risk factor for anorexia nervosa. However the absence of linkage and the existence of negative association studies raise the possibility of false positive findings, resulting from population stratification or lack of statistical power. To address this controversy we recruited a sample of 316 patients with anorexia nervosa from six European centres, and utilised a family-based transmission disequilibrium (TDT) approach to analyse the HTR2A-1438 G/A polymorphism. Age at onset and minimal BMI were also taken into consideration in order to detect clinical heterogeneity or a quantitative trait effect. The TDT approach showed that the A allele was transmitted 133 times and not transmitted 148 times (McNemar chi(2) = 0.29, df = 1, P = 0.59). Also, the haplotype-based haplotype relative risk method showed no evidence for association of the A allele, in samples from each centre (chi(2) < 2.15, df = 1, P > 0.14) and in the total sample (chi(2) = 0.55, df = 1; P = 0.46). Furthermore, we found no evidence for heterogeneity of the A allele frequency between samples (chi(2) = 2.54, df = 4, P = 0.64), either according to minimal-BMI (F1/242 = 2.14, P = 0.45) or age at onset (F1/224 = 2.39; P = 0.12). QTL-TDT analyses also showed no direct role of the A allele on these traits. We thus found no evidence for a significant role of the 5-HT(2A) gene in anorexia nervosa. Previous results may have been exposed to stratification bias (which we controlled by the TDT method) and/or the risk of type 1 error (from which we were less exposed because of the sample size).

Adolescent↗
PubMed2002

Genetic predisposition to obesity in bulimia nervosa: a mutation screen of the melanocortin-4 receptor gene.

Obesity has been identified as a risk factor for the development of bulimia nervosa (BN). Accordingly, we hypothesize that genotypes predisposing to obesity can be detected in patients with this eating disorder. In order to investigate this hypothesis we screened the melanocortin-4 receptor gene (MC4R) for mutations using single strand conformation analysis in 81 female inpatients treated for BN. A single patient with both extreme obesity and BN had a haplo-insufficiency mutation in the MC4R. Comparison of current and maximal body mass index (BMI) of all patients with cross-sectionally obtained BMI in the general population revealed an age appropriate distribution for current BMI and a substantially increased frequency for overweight at time of maximal BMI. Our findings suggest that overweight is a risk factor for BN in clinically ascertained patients. For the first time a genotype predisposing to obesity has been detected in an extremely obese patient with BN.

Adolescent↗
PubMed2002

5-HT2A promoter polymorphism -1438G/A in children and adolescents with obsessive-compulsive disorders.

Positive association between obsessive compulsive disorder (OCD) and the A-allele of the 5-HT(2A)-receptor promoter polymorphism -1438G/A has recently been reported in adults. We performed an association analysis of this polymorphism in 55 children and adolescents with OCD and in 223 controls consisting of unrelated students. We detected statistically significant differences in genotype (P < 0.05) and allele frequencies (P < 0.05) between individuals with OCD and controls. In this, to our knowledge, first association study based on children and adolescents with OCD, we confirm an association of the A-allele of the 5-HT2A receptor gene with OCD.

Adolescent↗
PubMed2002

[Pharmacological agents for treatment of paraphilias and hypersexual disorders].

We review the indications, modes of action, effectiveness, side effects, legal and ethical aspects of pharmacological agents which reduce sexual desire. It needs to be emphasized that these agents - regardless of their indication - should never be used without concomitant psychotherapy. Nevertheless, in this review we focus on pharmacotherapy, because it can be an important part of the therapeutic procedure and appropriate knowledge is required. A part of the review pertains to the therapy of male adolescents.

Adolescent↗
PubMed2002

Circulating soluble leptin receptor and free leptin index during childhood, puberty, and adolescence.

Leptin is bound in human blood by a high affinity binding protein, which appears to be identical with the soluble leptin receptor (sOB-R). Using a ligand-mediated immunofunctional assay for the determination of serum sOB-R, we investigated its course during childhood, puberty, and adolescence in a large cohort of 581 healthy children and adolescents and a small group of 13 patients with anorexia nervosa. In the first years of life, sOB-R is detectable in remarkably high concentrations. Thereafter, a continuous decline of sOB-R levels was found. Consequently, correlation analyses demonstrated significant inverse relationships (P < 0.001) of sOB-R with age, IGF-I levels, pubertal stage, auxological and body composition parameters, as well as with leptin concentrations. Multiple regression analysis revealed that height, IGF-I, and age (only in girls) were independent predictors of sOB-R levels; these variables account for approximately 65% and 48% of the variation of sOB-R levels in boys and girls, respectively. The courses of age-dependent median values for the free leptin index (FLI, ratio between leptin and sOB-R levels) and for leptin levels were parallel in both genders. Correlation analyses demonstrated that in particular parameters of growth and sexual maturation are more closely related to the FLI than to leptin alone; this closer relationship is more pronounced among boys. Weight gains of patients with anorexia nervosa resulted in a significant increase in leptin and IGF-I levels (P < 0.01), whereas the median of sOB-R values decreased (P < 0.01). sOB-R and IGF-I levels were again significantly correlated (r = -0.55, P < 0.01). These findings suggest that high levels of sOB-R in emaciation may reflect an up-regulation of the sOB-R to suppress leptin action during energy deficiency. Furthermore, determinations of sOB-R and FLI are additional valuable tools to investigate the leptin axis during growth and sexual maturation.

Adolescent↗
PubMed2001

[Asperger syndrome: an update].

OBJECTIVES: Asperger's Syndrome is a pervasive developmental disorder that manifest itself at pre-school age. It is characterized by qualitative impairments of social interaction, deficits in empathy, motor disturbances, and restricted repetitive and stereotyped patterns of behavior, interests and activities. A genetic etiology is assumed in context with brain dysfunctions and neuropsychological deficits which are all focused upon nonverbal learning, even though the general intellectual level is within the normal range. Treatment must take into account the individual aspects of each case and is based mainly on behavior therapy, group training of social skills, vocational training and adaptation, and if necessary, on medication. Medical treatment is indicated in the presence of special symptoms such as hyperactivity, aggressive behavior, sleep disorders, or depression.

Adult↗
PubMed2001

Systematic screening for mutations in the human necdin gene (NDN): identification of two naturally occurring polymorphisms and association analysis in body weight regulation.

BACKGROUND: NDN, which codes for the human necdin protein, is a candidate gene for Prader-Willi syndrome (PWS). One feature of this neurogenetic disorder is hyperphagia resulting in extreme obesity observed later in development. OBJECTIVE AND DESIGN: In this study we have used single-strand conformation polymorphism (SSCP) analysis to identify sequence variants at the human necdin gene. Furthermore we tested whether these variants were associated with obesity in extremely obese German children and adolescents. RESULTS: Two gene variants could be identified: a g.1352T-->C polymorphism in the putative promotor region and a silent g.2311C-->T polymorphism in the coding region. Genotype and allele frequency distribution of both of the polymorphisms were not significantly different between lower and higher body mass index (BMI) subjects. CONCLUSIONS: Hence, it is unlikely that these polymorphisms play a major role in the emergence of juvenile onset human obesity.

Adolescent↗
PubMed2001

The genetics of obesity: practical implications.

Over the past years substantial progress has been made in the molecular elucidation of monogenic forms of obesity both in rodents and in humans. In addition, several quantitive trait loci have been mapped in mice. In humans, non-parametric linkage studies have led to the identification of relevant chromosomal regions, some of which have already been confirmed. In this review we focus on an interpretation of the heritability estimates obtained in twin, family and adoption studies. These estimates include both direct and indirect genetic effects. Non-additive genetic factors seemingly contribute even more than additive factors. The importance of the non-shared environment is stressed. Gene x gene interactions need to be considered when interpreting recent molecular genetic results pertaining to haplo-insufficiency mutations in the melanocortin-4 receptor gene. We conclude by discussing the implications of the recent molecular findings in humans for phenotypical assessment in ongoing family studies.

Age Factors↗
PubMed2001

Association between an agouti-related protein gene polymorphism and anorexia nervosa.

Anorexia nervosa (AN) is a life threatening disorder affecting mostly adolescent women. It is a dramatic psychiatric syndrome accompanied by severe weight loss, hyperactivity and neuroendocrine changes (reviewed in Refs 1 and 2). Several studies have shown a strong genetic component in AN (reviewed in Ref 3). Recent advances in unraveling the mechanisms of weight control point to a crucial role of the melanocortin-4 receptor (MC4-r) system in regulating body weight. The orexigenic neuropeptide agouti-related protein (AGRP), a MC4-r antagonist, plays a crucial role in maintaining body weight, by inducing food intake. The sequence of the coding region of the human AGRP gene (AGRP) was determined and the AGRP of 100 patients with AN was screened for variations. Three single nucleotide polymorphisms (SNPs) were identified and screened in a further 45 patients and 244 controls. Two alleles were in complete linkage disequilibrium and were significantly enriched in anorectic patients (11%; P = 0.015) compared to controls (4.5%). These data indicate that variations of AGRP are associated with susceptibility for AN. This is possibly caused by defective suppression of the MC4-r by the variant AGRP, leading to a decreased feeding signal, increasing the risk of developing AN. These results implicate that antagonism of the MC4-r might be considered as pharmacotherapy for patients with AN.

Adolescent↗
PubMed2001

No evidence for involvement of alleles of the 825-C/T polymorphism of the G-protein subunit beta 3 in body weight regulation.

The 825-C/T polymorphism of the beta 3 subunit of the heterotrimeric G protein gene (GNB3) has been shown to be associated with essential hypertension in humans. Recently, it was also reported that the 825-T allele has a higher frequency in obese than non-obese hypertensives suggesting that the primary effect of this allele is on body weight. The association to hypertension might merely be a secondary effect of the higher weight of the respective allele carriers. To investigate an involvement of the 825-T allele in body weight regulation in young individuals, we evaluated allele frequencies in 440 extremely obese children and adolescents (82.9% had a body mass index [BMI] > or = 99th percentile), 51 obese students (BMI > or = 90th percentile), 110 normal weight students (BMI between 40th and 60th percentile) and 144 underweight students (BMI < or = 15th percentile). The study groups were genotyped by polymerase chain reaction with subsequent restriction fragment length polymorphism analysis (PCR-RFLP). The one-sided Yates-corrected chi(2)-test and the Cochran-Armitage trend test for association were performed. Tests for association were negative. The 825-T allele frequencies were similar in the four study groups belonging to different weight ranges (extreme early onset obesity: 0.29; obesity: 0.28; normal weight: 0.35; underweight: 0.32). Similarly, genotype frequencies did not differ between the groups. We concluded that the 825-T allele of the GNB3 does not play a major role in weight regulation in German children, adolescents and young adults.

Adolescent↗
PubMed2001

Serum leptin, gonadotropin, and testosterone concentrations in male patients with anorexia nervosa during weight gain.

Amenorrhea in female patients with anorexia nervosa is associated with low leptin secretion, thus suggesting a causal link. In an attempt to address the hypothesis that leptin also influences the hypothalamo-pituitary-gonadal function in males, we studied three male patients with acute anorexia nervosa longitudinally. Serum levels of leptin, LH, FSH, testosterone, and SHBG were measured on a biweekly basis during weight gain. Leptin levels at low body mass index values were below the 5th percentile. During weight gain, leptin levels reached or surpassed the 95th percentile. The temporal dynamics of body mass index and fat mass were closely related to those of leptin concentrations in serum. Leptin increments were paralleled by increments of gonadotropins, testosterone, and the free androgen index (FAI). In each of the patients, serum concentrations of leptin were positively correlated with those of testosterone (P = 0.0001, P = 0.01, P = 0.07, respectively) and FAI (P = 0.0001, P = 0.0001, P = 0.09, respectively). In addition, in the combined data set of all patients changes of leptin over time were positively correlated with changes in LH (P = 0.01), FSH (P = 0.0001), testosterone (P = 0.002), and FAI (P = 0.002). In conclusion, these data suggest that leptin might also play an important role in the regulation of the hypothalamo-pituitary-gonadal axis and fertility in underweight males as has previously been shown in underweight females.

Adipose Tissue↗
PubMed2001

Identification of a deletion variant in the gene encoding the human alpha(2A)-adrenergic receptor.

OBJECTIVE: The alpha(2)-adrenergic receptors are involved in the effects of catecholamines on energy metabolism. Of three known subtypes with differential expression, alpha(2A)-adrenergic receptors are also localized in adipose tissue where they counteract the lipolytic activity of beta-adrenergic receptors. This study was undertaken to assess whether variants in the alpha(2A)-adrenergic receptor gene are associated with body weight. DESIGN AND METHODS: Single strand conformation polymorphism (SSCP) screening and subsequent sequencing were applied to determine genetic variants in DNA samples from individuals with obesity, those of normal weight and those underweight. RESULTS: Analysis of the coding region resulted in the identification of an 18 bp deletion, with no other mutation found. Of 429 genotyped subjects, 7 carried the deletion, with no significant differences between lean and obese subjects. A previously identified polymorphism in the promoter of the alpha(2A)-adrenergic receptor gene also did not show an association with any of the tested body weight categories. CONCLUSION: Our data suggest that variants in the alpha(2A)-adrenergic receptor gene are unlikely to contribute to the predisposition for the lean or obese state.

Adolescent↗
PubMed2001

Prospective 10-year follow-up in adolescent anorexia nervosa--course, outcome, psychiatric comorbidity, and psychosocial adaptation.

The aim of the present study was to follow up the long-term course of adolescent-onset anorexia nervosa by repeated assessment, to analyze the association between the course of the eating disorder and psychiatric comorbidity, and to evaluate psychosocial outcome. The sample consisted of 39 inpatients who were reinvestigated 3, 7, and 10 years after discharge. The patients and 39 controls matched for age, gender, and occupational status were assessed with structured interviews on DSM-III-R eating disorders, additional axis I and axis II psychiatric disorders, and psychosocial functioning. Results showed that 69 % of the original subjects met the criteria for full recovery at the 10-year follow-up. One patient (3%) still exhibited the full syndrome of restrictive anorexia nervosa, two patients (5%) the full syndrome of bulimia nervosa. None of the patients had died. Of the subjects, 51% currently had an axis I psychiatric disorder and 23% met the full criteria for a personality disorder. Apart from the eating disorder, anxiety disorders and avoidant-dependent and obsessive-compulsive personality disorders were the most common psychiatric diagnoses. There was a significant association between psychiatric comorbidity and the outcome of the eating disorder and between outcome and psychosocial adaptation. With regard to psychiatric morbidity and psychosocial functioning, long-term recovered patients did not differ significantly from normal controls. It is concluded that in most patients adolescent anorexia nervosa takes a prolonged course, although it seems to be more favorable than in adult-onset forms. Those who achieve complete recovery from the eating disorder have a good chance of overcoming other psychiatric disorders and to adapt to social requirements.

Adaptation, Psychological↗