Summary: Where and when the children’s grandparents and parents were born could contribute to an increased risk of ASD in their offspring.
Source: University of Utah
When and where are often vital clues for epidemiologists, the medical sleuths who help solve the mysteries underlying disease. The technique dates back to at least the 19th century in London, where a physician named John Snow mapped cholera deaths and traced the source of the outbreak to a single well in the city. Once the well was closed, the outbreak ended.
Taking this idea to a new level, scientists at the University of Utah Health, using a unique combination of geographic and demographic data, recently concluded that when and where parents and grandparents of children in Utah born and raised could contribute to an increased risk of autism among their children. offspring.
The scientists believe this new approach could be used to explore the temporal and spatial aspects of any disease for which family pedigree information is available.
The study published in the International Journal of Health Geographyis among the first to assess the influence of time and space (when and where) across generations on increased risk of autism.
Over time, the researchers say, this discovery could lead to the identification of environmental factors, such as exposure to pollutants, that could have disruptive effects on genetic information passed between generations.
“Looking at families and where and when they lived has helped us detect groups of individuals who appear to have a higher later risk of autism among their descendants,” says James VanDerslice, environmental epidemiologist at the Division of Public Health at the U of U Health and lead author of the study.
“Knowing that the parents and grandparents of these autistic children shared space and time brings us closer to understanding the environmental factors that may have influenced this health outcome.”
Multigenerational epidemiological studies are difficult and time-consuming, says Rebecca Richards-Steed, the study’s principal investigator and a graduate student in the Department of Geography at the University of Utah. In fact, most of these studies have been done on animals, which reproduce rapidly and can be tracked for multiple generations in a shorter time frame than in humans.
Using existing technology in a new way, VanDerslice and Richards-Steed circumvented this drawback by examining existing data available to parents and grandparents to identify places and times that may be associated with factors. risk factors that increase the risk of disease in subsequent generations.
Researchers used the Utah Autism and Developmental Disabilities Registry, in conjunction with the Utah Population Database (UPDB), to identify parents and grandparents of children born between 1989 and 2014 with autism.
Birth certificates, driver’s license information, and census and medical records from the UPDB have helped scientists track when and where these people lived over time. The UPDB is one of the few databases in the world to include this type of information.
For comparison, they randomly selected parents and grandparents of children from the UPDB database who had not been diagnosed with autism. The names of the individuals have not been released to the researchers.
In total, VanDerslice and her colleagues identified where 7,900 parents and 31,600 grandparents were born and raised. They identified 20 key clusters, or groupements, scattered across the state. After analysis, 13 of the 20 groups – nine among grandparents and four among parents – were associated with a high risk of autism in their children or grandchildren. In particular, descendants of paternal grandparents were about three times more likely to have autism than expected.
“What we saw aligns with current scientific understanding of how paternal genetics is key to evolutionary change and adaptation,” Richards-Steed said. “So it’s entirely possible in the case of autism that a signal, shaped in part by environmental experiences, comes from the paternal line, which is passed down through the family.”
Seven clusters, all rural, had low risk of an association between autism and family lineage.
“We really don’t know why some rural areas seemed to have what you might call a protective effect,” says Richards-Steed. “It is certainly possible that parents and grandparents living in urban areas had different environmental exposures or experiences.”
“What we can say, based on our findings, is that what we’re exposed to now probably doesn’t just affect us or even our children, but maybe even our children’s children.”
Going forward, researchers will dig deeper into factors, including lifestyle, that might help explain these findings.
“Evidence shows that our environment has a deterministic effect on our growth and development, which includes the germ cells we carry for the next generation,” says VanDerslice.
“Examining the space and time shared by our ancestors can give us clues about environmental factors that may drive biological changes that increase the risk of disease in future generations.”
See also
Scientists believe this new approach could be used to explore temporal and spatial aspects of other conditions where family ancestry information is available.
“This idea is not limited to autism,” says Richards-Steed. “It can be applied to any disease and could improve our ability to understand how a confluence of genetic and environmental factors can have long-term health consequences for families.”
About this autism research news
Author: Press office
Source: University of Utah
Contact: Press Office – University of Utah
Picture: Image is in public domain
Original research: free access.
“Evidence of transgenerational effects on autism spectrum disorders using multigenerational spatio-temporal cluster detectionby Rebecca Richards Steed et al. International Journal of Health Geography
Summary
Evidence of transgenerational effects on autism spectrum disorders using multigenerational spatio-temporal cluster detection
Background
Transgenerational epigenetic risks associated with complex health conditions, such as autism spectrum disorders (ASD), have attracted increasing attention. Transgenerational exposures to environmental hazards with potential for epigenetic effects can be effectively identified using spatio-temporal clustering. Specifically applied to the ancestors of diseased individuals, spatiotemporal clustering characterized for vulnerable developmental stages of growth can provide a measure of the relative risk of disease in offspring.
Goals
(1) Identify spatiotemporal clusters of ancestors with a descendant with a clinical diagnosis of ASD and matched controls. (2) Identify ancestor developmental windows with the highest relative risk of ASD in offspring. (3) Identify how relative risk may vary by maternal or paternal line.
Methods
Family pedigrees linked to places of residence of ASD cases in Utah were used to identify spatiotemporal groups of ancestors. Family control pedigrees of no cases based on age and sex were matched to cases 2:1. Data were categorized by maternal or paternal line at birth, childhood, and adolescence. A total of 3957 children, both parents and maternal and paternal grandparents were identified. Bernoulli’s space-time binomial relative risk (RR) analysis statistic was used to identify clusters. Monte Carlo simulation was used for statistical significance testing.
Results
Twenty statistically significant groups were identified. Thirteen spatio-temporal clusters with increased RR (>1.0) were identified from maternal and paternal lines at a p-value <0.05. Paternal grandparents carry the highest RR (2.86 to 2.96) during birth and childhood in the 1950s to 1960s, which represent the smallest size clusters and occur in urban areas. Additionally, seven statistically significant clusters with RR < 1 were relatively large, covering more rural areas of the state.
Conclusion
This study identified statistically significant spatio-temporal clusters during critical developmental windows that are associated with ASD risk in offspring. Geographic space and time brings together the family pedigrees of more than 3 generations, which we call a person’s family tree. geographical heritage, is a powerful tool to study transgenerational effects that may be epigenetic in nature. Our novel use of spatio-temporal clustering can be applied to any disease for which family pedigree data is available.
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