According to the United States Department of Developmental Services, the prevalence of autism spectrum disorders increased 556% from 1991 to 1997 [1]. One in every eight boys is diagnosed with autism, and boys are four times more likely to be affected by this disease than girls. Also, one out of every sixty-eight families has a child with autism. Incidences of autism are increasing by 3.8% per year worldwide and by 15% in the USA [1]. The common signs of autism are marked by: (1) qualitative impairment in social interaction; (2) qualitative impairments in communication; (3) restricted repetitive and stereotyped patterns of behavior. Autism covers a continuum of disorders beginning from mild autism and Asperger’s Syndrome to severe autism. Autism Spectrum Disorder is defined only behaviorally, which often contributes to the heterogeneity of cohort studies. Factors such as age, gender, IQ, and behavioral traits often diverge considerably, with non-uniform matching of controls.

The six autistic participants, their parents, siblings and control groups were tested using biometric device based on gas discharge visualization (GDV). It is a non-invasive imaging technique used to assess the functional state of human body by recording the responses of the autonomic nervous system to a high intensity electromagnetic field using fingertips. The method is based on acupuncture approach, where organs and organ systems are connected by electron communication. The classification of acupuncture points for GDV has been developed by Mandel and Korotkov and is presented in Figure 1. The respective sectors of the fingertips correspond to specific organs/organ systems including the immune, respiratory, digestive, cardiovascular, central nervous, peripheral nervous, urino-genital, and endocrine systems [2–6].

The aim of our pilot study was to compare autistic individuals with controls and non-autistic siblings as well as to compare their parents with parents who do not have autistic children and analyze statistically the obtained results for possible common difference regarding particular acupuncture regions present on the fingertips.

The results of the screening of autistic individuals, their parents and siblings as well as control groups are presented graphically in Table 1, Table 2, and Table 3. Five groups were compared: (1) autistic children and controls (marked with green color) (Table 1), (2) siblings from the families with autistic children and controls (marked with blue color) (Table 2), (3) autistic children and siblings (marked with yellow color) (Table 2), (4) fathers of autistic children and controls (marked with grey color) (Table 3), (5) mothers of autistic children and controls (marked with pink color) (Table 3). The comparison of captures without filter and with filter within mentioned groups was done on the level of individual values assigned to the specific acupuncture regions of fingertips. Out of total of 48 acupuncture points present on ten fingertips of both hands and associated to organs/organ systems, autistic children differed significantly from controls (p < 0.05) in 36 (images without filter) and 12 (images with filter), siblings differed significantly from controls (p < 0.05) in 12 (images without filter) and seven (images with filter), autistic children differed significantly (p < 0.05) from siblings in eight (images without filter) and one (images with filter), fathers of autistic children differed significantly (p < 0.05) from controls in 14 (images without filter) and three (images with filter) and mothers of autistic children differed significantly (p < 0.05) from controls in five (images without filter) and nine (images with filter) acupuncture points.

The statistical analysis of data of autistic children versus controls in Table 1. (images without filter) has demonstrated statistically significant difference (p < 0.05) for the acupuncture regions corresponding to right eye, right ear, nose, maxillary sinus, jaw and teeth right side, throat, trachea, larynx, thyroid gland, jaw and teeth left side, left ear, left eye, cerebral cortex, thorax zone, lumbar zone, coccyx, pelvis minor zone, blind gut, appendix, ascending colon, transverse colon, descending colon, mammary glands and respiratory system, immune system, liver, cardiovascular system, cerebral vessels, abdominal zone, hypophysis, thyroid, pancreas, adrenal gland, urino-genital system, spleen, nervous system, epiphysis, duodenum, ileum and jejunum. Analysis of the images with filter pointed out statistically significant difference (p < 0.05) for acupuncture regions corresponding to right ear, nose, maxillary sinus, jaw and teeth right side, throat, larynx, trachea, thyroid gland, left eye, lumbar zone, pancreas, spleen, nervous system, ileum, jejunum and right part of heart.

Also, significantly different (p < 0.05) were integral parameters of autonomic tone (activation coefficient) and area of electro-photonic emission (images without filter) (Table 1).

Comparison of siblings with controls (Table 2) showed statistical significance (p < 0.05) of following variables (images without filter): jaw and teeth left side, thorax zone, lumbar zone, appendix, ascending colon, gallbladder, liver, pancreas, spleen, nervous system, epiphysis and jejunum. Statistical analysis of data obtained from the images with filter indicate significant difference (p < 0.05) for right eye, lumbar zone, coccyx, pelvis minor zone, thyroid gland, hypothalamus, mammary glands and respiratory system and jejunum.

Also, significantly different (p < 0.05) were integral parameters of autonomic tone (activation coefficient) and entropy of electro-photonic emission (images with filter) (Table 2).

Within groups of autistic children and siblings (Table 2) statistically significant (p < 0.05) difference was found for acupuncture regions corresponding to throat, larynx, trachea, thyroid gland, descending colon, liver, left kidney, abdominal zone, hypophysis, urino-genital, mammary glands and respiratory system (images without filter) and mammary glands and respiratory system (images with filter).

Also, significantly different (p < 0.05) were integral parameters of autonomic tone (activation coefficient) and area of electro-photonic emission (images without filter) (Table 2).

Fathers of autistic children versus control group (Table 3) exhibited statistically significant difference (p < 0.05) in the regions of left ear, nose, maxillary sinus, left eye, thorax zone, sacrum, coccyx, pelvis minor zone, blind gut, appendix, immune system, right kidney, thyroid gland, hypothalamus, epiphysis, mammary glands and respiratory system and heart (images without filter) and throat, larynx, trachea, thyroid gland, mammary glands and respiratory system and heart (images with filter).

Mothers of autistic children versus control group (Table 3) demonstrated statistically significant difference (p < 0.05) in acupuncture regions corresponding to right eye, right ear, nose, maxillary sinus, throat, larynx, trachea, thyroid gland, left eye and epiphysis (images without filter) and right eye, jaw and teeth left side, left ear, nose, maxillary sinus, left eye, cervical zone, thorax zone, abdominal zone, pancreas and right part of heart (images with filter).

The GDV biometric technique has been successfully used in psychology and cognitive studies mainly to assess the psycho-emotional and physiological state of an individual as well as to evaluate the changes that take place in a human organism over a period of time. Based on integral parameters such as form and size of electro-photonic emission, symmetry and relationship of the captured image with the rest of the GDV-grams of all fingertips, the presence or absence of aggressive signs and defects with the organs/organ systems one can conclude about the functional state of an individual at the moment of study [7,8].

Autism is a severe neurodevelopmental disorder with the development prior to 3 years of age [9]. The cause of autism remains unknown, and it is a heterogeneous disorder as to its etiology and phenotype. Autistic children are vulnerable to oxidative stress and are easily influenced by genetic, environmental, and immunological factors [10]. Immune [10–13], autoimmune, and infectious factors [14,15] have also been mentioned as playing role in the manifestation of autism. GDV assessment of psycho- emotional and physiological state of autistic individuals confirms that acupuncture regions on fingertips corresponding to the regions of “spleen” and “immune system” significantly differ from the same regions in controls (Table 1). The genetic nature of autism is unclear; there is no single gene that has been found to be associated with autism. Instead, multiple genes have been reported as being associated with autism [16]. Patients with autism can differ in the severity and scope of their symptoms suggesting that multiple factors contribute to explaining the disorder’s symptoms. Environmental aspects, such as mercury, lead, measles, rubella virus, retinoic acid, maternal thalidomide, valproic acid and alcohol use during pregnancy and stress have been implicated in autism [17,18]. In addition, patients with autism are described as having behavior impairments, gastrointestinal deviations [19] and epilepsy [20]. According to GDV testing, autistic children have shown significant difference from normal children in acupuncture regions corresponding to descending, transverse, ascending colon, blind gut, appendix, pelvis minor zone as well as nervous system which may relate to behavioral impairments in autistic individuals. Recent clinical evidence emphasizes the significance of oxidative stress in the development and expression of autism [21]. Interestingly, autistic children in our experimental setting have acupuncture regions corresponding to respiratory system, trachea, larynx, maxillary sinus significantly different from controls and many impaired manifestations in autism relate to weakness of respiratory muscle in autistic patients [22]. There are numerous studies in the medical literature [23–30] that confirm cerebral hypoperfusion (decreased blood flow to the brain) in as many as 86% of individuals with autism [23]. Furthermore, this diminished blood flow typically correlates with many core autistic symptoms. Thus, it has been suggested that abnormal areas in the cerebral cortex are related to the cognitive impairments (such as deficits in language, impaired executive function and abnormal responses to sensory stimuli) observed in autistic children. In fact, sometimes the cerebral blood flow actually decreases, and this appears to be mediated, in part, by inappropriate vasoconstriction (narrowing of blood vessels) instead of vasodilation [31]. Cerebral hypoperfusion appears to lead to cerebral hypoxia (impaired oxygen delivery) to the brain in some autistic individuals. The cause of cerebral hypoperfusion in autistic individuals is unknown, but might be due to inflammation. Inflammation around blood vessels can cause the vessel wall to become stiff and inflexible. Vasculitis decreases the ability of the blood vessel to dilate and can lead to diminished blood flow. Other studies confirm the presence of inflammation in the brain of some autistic individuals. Inflammation, generally associated with increased content of water (edema), can increase the space between cells [32], and might increase the amount of fluid present inside cells [33]. Furthermore, the ability of one brain cell to communicate to another cell is reduced in some autistic children when compared to neurotypical children [34]. Thus, there exists a high probability that inflammation present in the brain of some autistic individuals is leading to diminished blood flow, impaired functional connectivity, impaired cognition, and increased fluid inside brain cells. Researchers at the Pennsylvania School of Medicine have shown constricted blood vessels and low blood flow in autistic individuals via biochemical analysis [35]. Our results shown in Table 1 confirm that there is a significant difference between autistic children and normal children (images without filter) for acupuncture region corresponding to cerebral vessels and cerebral cortex which could imply that autistic children may have malfunctioning blood flow in cerebral vessels and cortex.

All compared groups have shown significant difference on both psycho-emotional (images without filter) and physiological (images with filter) levels. However, the differences between autistic children and controls expressed on psycho-emotional level were the most significant as compared to the other groups. Therefore, the activity of the sympathetic autonomic nervous system is significantly altered in children with autism. The biometric method based on GDV is a promising step in autism research that may lead towards creating a disease profile and identify unique signature/biomarker for autism. Further work should involve more participants in order to augment our findings.