Aneta Kubranská

Polymorphisms of candidate genes in Slovak autistic patients.

Autism is one of the most genetically influenced neuropsychiatric disorders. However, its detailed genetic basis is far from being clear. Genome-wide association studies have revealed a number of candidate genes, mostly related to synaptogenesis and various neuroendocrine pathways. In our study we have focused on oxytocin (OT), oxytocin receptor (OXTR), GABA receptor gamma 3 (GABRG3), neuroligin (NLGN4X), and reelin (RELN). After signed consent, 90 autistic boys and 85 healthy controls were enrolled in the study. Polymorphisms of OT (rs2740204), OXTR (rs2228485), GABRG3 (rs28431127), and NLGN4X (rs5916338) were analyzed using restriction fragment length polymorphism. (GGC)n STR polymorphism in the 5′ UTR of the RELN gene was genotyped using fragment analysis. The only significant association in autistic boys in Slovakia was found with higher number of GGC repeats in the RELN gene (P=0.001) potentially explaining lower RELN levels in blood and brain of autistic patients.

Mental rotation in intellectually gifted boys is affected by the androgen receptor CAG repeat polymorphism

Testosterone was shown to organize brain and modulate cognitive functions. It is currently unknown whether mental rotation is also associated with prenatal testosterone exposure and testosterone-related genetic polymorphisms. The aim of our study was to analyze associations between mental rotation performance, the actual testosterone levels, the prenatal testosterone level (expressed as 2D:4D ratio) and the androgen receptor CAG repeat polymorphism in intellectually gifted boys. One hundred forty-seven boys aged 10-18 years with IQ>130 were enrolled. Saliva samples were collected and used for ELISA of actual levels of salivary testosterone. The 2D:4D finger length ratio as an indicator of prenatal testosterone was measured on both hands and averaged. Amthauer mental rotation test was used for the assessment of this spatial ability. The CAG repeat polymorphism in the androgen receptor gene was analyzed using PCR and capillary electrophoresis. Linear regression revealed that 2D:4D finger length ratio and the number of CAG repeats in the androgen receptor gene were associated with mental rotation. Actual levels of testosterone did not correlate significantly with mental rotation. Multivariate analysis of covariance revealed that after adjustment of age as a confounding variable, only the effect of the genetic polymorphism was significant. The results are in line with our previous genetic analysis of intellectually gifted boys showing the importance of CAG repeat polymorphism in the androgen receptor gene. Details of the interactions between androgen signaling, testosterone levels and its metabolism especially during the prenatal development of brain function remain to be elucidated.

Testosterone and Androgen Receptor Sensitivity in Relation to Hyperactivity Symptoms in Boys with Autism Spectrum Disorders.

Introduction Autism spectrum disorders (ASD) and hyperactivity symptoms exhibit an incidence that is male-biased. Thus androgen activity can be considered a plausible biological risk factor for these disorders. However, there is insufficient information about the association between increased androgen activity and hyperactivity symptoms in children with ASD. Methods In the present study, the relationship between parameters of androgenicity (plasmatic testosterone levels and androgen receptor sensitivity) and hyperactivity in 60 boys (age 3–15) with ASD is investigated. Given well documented differences in parent and trained examiners ratings of symptom severity, we employed a standardized parent`s questionnaire (Nisonger Child Behavior Rating Form) as well as a direct examiner`s rating (Autism diagnostic observation schedule) for assessment of hyperactivity symptoms. Results Although it was found there was no significant association between actual plasmatic testosterone levels and hyperactivity symptoms, the number of CAG triplets was significantly negatively correlated with hyperactivity symptoms (R2 = 0.118, p = 0.007) in the sample, indicating increased androgen receptor sensitivity in association with hyperactivity symptoms. Direct trained examiner´s assessment appeared to be a relevant method for evaluating of behavioral problems in the investigation of biological underpinnings of these problems in our study. Conclusions A potential ASD subtype characterized by increased rates of hyperactivity symptoms might have distinct etiopathogenesis and require a specific behavioral and pharmacological approach. We propose an increase of androgen receptor sensitivity as a biomarker for a specific ASD subtype accompanied with hyperactivity symptoms. Findings are discussed in terms of their implications for practice and future research.

Spatial abilities are not related to testosterone levels and variation in the androgen receptor in healthy young men.

Androgens modulate brain functions such as cognition, emotions and ability. Several studies have shown a correlation between testosterone levels and mental rotation. The aim of the present study was to confirm the influence of salivary testosterone levels, 2D/4D ratio (such as a putative marker of prenatal testosterone), and sensitivity of androgen receptor on the mental rotation in healthy young men. Seventy-five healthy young men (age, 21.86 year) volunteered in this study. Mental rotation scores of our subjects were assessed using the Vandenberg and Kuse Mental Rotation Test. The 2D/4D finger length ratio as an indicator of prenatal testosterone was used as an average measurement of both hands. Correlation analysis revealed no correlation between salivary testosterone levels and mental rotation. However, we have observed a trend towards a negative correlation. There were no statistically significant results between 2D/4D ratio and mental rotation or between polymorphic three-nucleotide (CAG) repeats and mental rotation tests. Future studies should focus on other genetic determinants of spatial abilities, potentially genes involved in testosterone metabolism.

Association with Autism of Two Polymorphisms in Gene Encoding Oxytocin Receptors in Slovakia

Study background: Autism is a complex neurodevelopmental disorder involving genetic components in its etiology. Oxytocin is a neuropeptide affecting social behavior acting in the CNS via binding its only type of receptor (OXTR). A number of studies have shown an association of polymorphisms in the OXTR gene and the diagnosis of autism in different ethnic populations. The aim of this study is to find an association of polymorphisms in the OXTR gene and the diagnosis of autism in Slovakia. Methods: After acquiring informed consent, 108 autism patients were recruited into the study (83 males, 25 females), in addition to 131 healthy children as a control group (106 males, 25 females). DNA was extracted from whole blood and four single nucleotide polymorphisms (rs223785, rs2270465, rs2268498, rs53576) were assessed using the PCR-RFLP method. Results: We found two positive associations of polymorphisms in OXTR with autism in boys, namely markers rs2270465 and rs237851 (p<0.0001 and p=0.0016). Both markers survived multiple comparison testing (p<0.0005, p<0.001, respectively). There were no significant differences in the genotype and allelic distribution among groups in girls. Conclusion: Polymorphisms in oxytocin receptor are associated with autism. The addition of psychological profiling may reveal possible correlations of gentoypes/alleles within OXTR with symptom severities.

The effect of mental rotation on changes in plasma testosterone and cortisol levels

Testosterone level has an influence on cognitive functions, especially spatial abilities. The relationship is, however, bidirectional and brain activity also affects testosterone levels. The aim of this study was to analyze the effects of an intensive 3D mental rotation task on testosterone levels in young healthy men and women. In the mental rotation task, men reached a higher top score (P=0.027) and total score (P=0.004) compared to women. In 8 out of 9 women (P=0.008) but not in men (P=0.129) testosterone levels decreased after one hour of mental rotation testing. A significant gender difference was shown (P<0.0001). In all women, plasma cortisol levels was significantly lower after testing (P=0.004). In men cortisol levels decreased in 7 out of 9 subjects (P=0.039). A significant gender difference was not found (P=0.19). No association was found in women between baseline testosterone levels and mental rotation total score (P=0.810). In men there was a positive correlation between baseline testosterone and mental rotation total score (P=0.015). A significant difference gender difference was seen in the association between testosterone and mental rotation score (P<0.05). Mental rotation stimuli caused significant changes in hormonal levels of testosterone and cortisol. A gender-specific response was detected in testosterone fluctuation.

Problem Behavior and Testosterone in Pre-pubertal Boys with Autism Spectrum Disorder

Aim The aim of this study was to compare testosterone level with clinical features of problem behavior in children with ASD. Methods The study sample consisted of 35 pre-pubertal boys with clinical diagnosis of ASD. In all children (ages 3-10) diagnosed as ASD, parents completed Nisonger Child Behavior Rating Form (NCBRF) (version for intellectual disabilities)-parent version. Rating scale assessed child´s behavior as observed in previous 1-2 months. Specific problem behavior was rated on subscales for conduct problems, anxiety, hyperactivity, self-injury/stereotypic behavior, self-isolated/ritualistic and overly sensitive. On this rating form parents also assessed social behavior: compliant behavior and adaptive social behavior. Total serum testosterone levels were determined after the parents completed rating forms, according to standardized procedure. Results It was found positive correlation between total serum testosterone levels and conduct problem subscale (p=0.007, r=0.445) and as well as total serum testosterone levels and overly sensitive subscale (p=0.03, r=0.348) of NCBRF. In other subscalesof NCBRF(problem behavior or social behavior) were no significant correlations. Conclusions The results suggest that there might be some relationship between problem behavior (specifically conduct problems and overal sensitivity) and testosterone levels in boys with ASD. Testosterone levels had no significant correlation with other subscales of NCBRF. However further research is needed for investigation of complex androgen activity (free TST levels, SHBD levels) and potential roles of other hormones in complex etiology of conduct problems and overall sensitivity in children with ASD. This findings rise interest in further investigation of relationship between testosterone and conduct problems and overall sensitivity in children with ASD and indicate that therapeutic strategies targeting testosteronecould be useful in the treatment of problem behaviors in children with ASD. This study was part of broader projects focused on ASD conducted in Autism Research Center for Autism (ARCA), Comenius University and was supported by grants APVV 02544-11 and VEGA1/0086/14.