Expert dismisses ‘baseless’ autism claims - Scientist says disorder has nothing to do with closely related people having children

A leading Caribbean genetics expert has forcefully shut down growing online chatter suggesting that autism may be linked to inbreeding, calling the idea scientifically baseless and dangerously misleading.

Dr Wayne McLaughlin, director of the Caribbean Institute for Genomic Medicine (CARIGEN) and deputy dean of Basic Medical Sciences at The University of the West Indies, has dismissed the claim outright, stressing that neurodevelopmental conditions such as autism spectrum disorder (ASD) arise from a far more complex mix of biological and environmental factors.

"That is completely different," he said, drawing a clear line between inherited genetic disorders and brain development conditions.

Instead, McLaughlin said neurodevelopmental conditions occur when something changes or disrupts the brain's development process before birth.

"Neurodevelopmental conditions wouldn't have anything to do with parents transferring a bad gene in that way. During development, something could change or go wrong, and that affects the outcome. It can involve both genetics and environmental factors -- there are a lot of things at play," he said.

ASD is a developmental condition caused by differences in the brain. Depending on their level on the spectrum, persons with autism can have problems, including difficulties with social communication and interacting with others.

His comments come amid growing misinformation circulating on social platforms that attempt to link autism to family genetic patterns in simplistic and inaccurate ways. The genomics expert warned that such claims ignore decades of scientific research and risk deepening stigma around both autism and inherited conditions.

From a medical standpoint, he said, inherited disorders do exist within families, but they follow entirely different biological pathways. Conditions such as sickle cell disease, diabetes, and certain cancers can pass through generations in predictable genetic patterns.

"What happens when closely related individuals have children is that there may be genes from each parent that carry some disease," McLaughlin said.

"These genes are usually in a recessive form, meaning they don't show. Only when two of those genes come together, then that disease will be expressed."

In everyday terms, a person can carry a faulty gene and never know it. But if both parents carry the same one, there is a chance it can show up in their child.

"When you do a cross between two individuals, it could happen that the two recessive genes come together and that means the disease will be expressed," he said.

McLaughlin noted that the effects can vary widely, depending on the genes involved.

"Genetics can cause issues with the eyes, the vision could be very blurred to the extent they have to wear glasses. There could be certain expressions of blood diseases like hemophilia and there are many others," he said.

Experts caution that many people who carry these genetic traits may never show symptoms themselves, yet can still pass them on to future generations.

Polygenics Consulting, a leading DNA testing company, said that in populations with shared ancestry, such as in Jamaica, it is not uncommon for individuals within the same family or community to unknowingly carry the same recessive gene.

"This significantly increases the likelihood of inherited conditions appearing in children when both parents are carriers," Polygenics said.

The DNA testing company said most families in Jamaica do not routinely pursue genetic screening prior to having children. It argues that the lack of preventative testing increases the likelihood of unknowingly carrying and passing on recessive genetic conditions.

"We strongly encourage individuals and couples to consider proactive testing," Polygenics said. "Investing in genetic awareness before starting a family can significantly reduce uncertainty and improve long-term health outcomes," it added.