Transcript levels of 4 genes in umbilical cord blood are predictive of later autism development: a longitudinal follow-up study.

BACKGROUND: Over recent decades, autism spectrum disorder (ASD) has been of increasing epidemiological importance, given the substantial increase in its prevalence; at present, clinical diagnosis is possible only after 2 years of age. In this study, we sought to develop a potential predictive model for ASD screening. METHODS: We conducted a longitudinal follow-up study of newborns over 3 years. We measured transcript levels of 4 genes (superoxide dismutase-2 [SOD2], retinoic acid-related orphan receptor-α [RORA], G protein-coupled estrogen receptor-1 [GPER], progesterone receptor [PGR]), 2 oxidative stress markers and epigenetic marks at the RORA promoter in case-control umbilical cord blood mononuclear cell (UCBMC) samples. RESULTS: We followed 2623 newborns; we identified 41 children with ASD, 63 with delayed development and 2519 typically developing children. We matched the 41 children with ASD to 41 typically developing children for UCBMC measurements. Our results showed that children with ASD had significantly higher levels of H3K9me3 histone modifications at the RORA promoter and oxidative stress in UCBMC than typically developing children; children with delayed development showed no significant differences. Children with ASD had significantly lower expression of SOD2, RORA and GPER, but higher PGR expression than typically developing children. We established a model based on these 4 candidate genes, and achieved an area under the curve of 87.0% (standard deviation 3.9%) with a sensitivity of 1.000 and specificity of 0.854 to predict ASD in UCBMC. LIMITATIONS: Although the gene combinations produced a good pass/fail cut-off value for ASD evaluation, relatively few children in our study sample had ASD. CONCLUSION: The altered gene expression in UCBMC can predict later autism development, possibly providing a predictive model for ASD screening immediately after birth.

Prenatal exposure of diabetes and progestin-mediated autistic biomarker in peripheral blood mononuclear cells.

Despite the importance of early diagnosis and intervention, the diagnosis of autism spectrum disorders (ASDs) remains delayed as it is mostly based on clinical symptoms and abnormal behaviours appearing after 2 years of age. Identification of autistic markers remains a top priority in achieving an early and effective ASD diagnosis. We have previously reported that prenatal exposure of hormones or diabetes triggers epigenetic changes and oxidative stress, resulting in gene suppression with autism-like behaviours in offspring. Here, a potential biomarker for ASD diagnosis was established through gene analysis in peripheral blood mononuclear cells (PBMCs). The study from in vivo mouse showed that prenatal hormone exposure or maternal diabetes suppresses mRNA expression of estrogen-related receptor α (ERRα), superoxide dismutase 2 (SOD2), G protein-coupled estrogen receptor (GPER) and retinoic acid-related orphan receptor α (RORA) in the brain as well as oxidative stress and mitochondrial dysfunction, subsequently triggering autism-like behaviour in mouse offspring. Also, similar gene suppression was found in hematopoietic stem cells (HSCs) and PBMC, with inherited epigenetic changes being identified on the related promoters. The human case-control study found that mRNA levels of ERRα, SOD2, GPER and RORA were significantly reduced in PBMC from ASD subjects (n = 132) compared with typically developing (n = 135) group. The receiver operating characteristic curve showed a .869 ± .021 of area under the curve for ASD subjects with 95% confidence interval of .829-.909, together with 1.000 of sensitivity and .856 of specificity. In conclusion, the combined mRNA expression in PBMC based on prenatal factor exposure-mediated gene suppression could be a potential biomarker for ASD diagnosis.