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Volume 8
Journal of Environmental & Analytical Toxicology
Environment and Health Congress 2018
July 11-12, 2018
July 11-12, 2018 Sydney, Australia
World Congress on
Environmental Toxicology and Health
Role of endocrine disturbing chemicals in development of autism spectrum disorders
Omar Bagasra
Claflin University, USA
A
utism Spectrum Disorder (ASD) is a set of complex developmental disorders whose etiology is unknown. Although
the symptoms may vary from person to person, they include impairment or loss of speech, lack of empathy and social
interaction deficiency. The cases of ASD have continued to increase drastically each year, with the CDC estimating 1:45 children
diagnosed, from 1 in 10,000 40 years ago. It is believed that the ASD is caused by a combination of genetic and environmental
factors, but recent studies suggest that epigenetic factors as well as exposure to endocrine disturbing environmental chemicals,
to which expecting mothers are exposed on a daily bases, may play a critical role in its pathogenesis. Although there are
no biomarkers for the disease, low levels of Oxytocin (OXY) and Arginine Vasopressin (AVP) have been reported. These
neuropeptides play a critical role in neurodevelopment of social interaction. Social interaction deficiencies are a principal sign
of ASD in children. OXY, is involved in social recognition, pair bonding and anxiety, as well as being linked to autism. Numerous
studies have shown that children with autism have plasma levels of OXY and AVP that are significantly lower than average. The
importance for normal OXY and OXY receptor function in males may explain how hormonal malfunction leads to ASD male
bias. Also, mothers of ASD children have lower levels of OXY and AVP and, in typical children, lower concentrations of OXY
in plasma are associated with lower social and cognitive functioning. There is an inexplicable bias toward males in classical
autism by a ratio of ~4:1, and ~10:1 in Asperger’s Syndrome (AS). The clinical picture is very heterogeneous and the etiology
is unknown. The heritability is high in ASD but no individual gene variants exerting a major impact on susceptibility have as
yet been identified. The mechanism for gender bias in autism is unknown although several hypotheses have been advanced
including: (1) Epigenetic mechanisms ‘the extreme male brain’ hypothesis of Baron-Cohen which postulates that elevated fetal
testosterone is a risk factor for ASD, (2) genetic mechanisms which involves X or Y chromosome inactivation and (3) recently,
Hu, et al. have shown that retinoic acid-Related Orphan Receptor Alpha (RORA) is reduced in the brain and lymphoblastoid
cell lines of multiple cohorts of individuals with ASD. This gene targets CYP19A1 (aromatase), in a gender-dependent manner
that can also lead to elevated testosterone (or male hormones-like chemicals) levels, a proposed risk factor for autism. To date,
none of these hypotheses have been either proven or disproven. Given the high clinical heterogeneity of ASD, it is possible
that each of these mechanisms for gender bias may apply to specific cohorts of individuals with ASD. We will present data on
the neuro-modifying effects of several endocrine disturbing chemicals on developing human brain neurons and their effects at
morphologic, immunologic and at molecular levels.
Biography
Omar Bagasra has completed his PhD from University of Louisville, Kentucky, USA and his MD from UACJ, Mexico. He has completed his Post-doctorate at Union
University, Albany, New York and Residency and Fellowships at Hahnemann University, Temple University, Schools of Medicine. He is the Founding Director of
South Carolina Center for Biotechnology at Claflin University, South Carolina, USA. He has published more than 140 papers in reputed journals and published over
10 books. His recent book describes the role of environmental factors in autism. He has been serving as Editorial Board Member of over 15 journals.
obagasra@claflin.eduOmar Bagasra, J Environ Anal Toxicol 2018, Volume 8
DOI: 10.4172/2161-0525-C1-011