Low CD38 expression in lymphoblastoid cells and haplotypes are both associated with autism in a family-based study.

Elad and colleagues looked at a gene called CD38 in families who have a child with autism.

They drew blood, grew white-blood-cell lines in the lab, and checked how much CD38 protein each sample made.

They also hunted for tiny DNA differences (haplotypes) that travel with the gene.

Cells from people with autism made far less CD38 than cells from their own parents or from unrelated controls.

Certain CD38 haplotypes showed up more often in children who had both autism and low daily living skills.

The same haplotypes were rare in the unaffected parents, pointing to a genetic risk pattern.

Northup et al. (1991) and Thompson et al. (1986) first linked high platelet serotonin to familial autism. Elad flips the coin: instead of more serotonin, they find less CD38, a gene that helps control social bonding hormones. The two markers sit on the same chemical pathway, so both papers point to a wonky serotonin system but from opposite ends.

Liu et al. (2016) and Xia et al. (2020) scanned the whole genome in East-Asian families and spotted many risk spots, including near CD38. Their big-picture maps now back up Elad’s single-gene hunch, showing the haplotype idea holds across ethnic groups.

Goldberg et al. (2009) saw lower serotonin-2 receptors in parents of kids with ASD. Elad’s low CD38 result in the children dovetails with this parental finding, strengthening the family-wide serotonergic story.

You can’t order a CD38 blood test yet, but you can tell families that immune-cell studies keep pointing to inherited serotonin differences in autism. When you write reports, note that low-functioning skills cluster with specific gene patterns; this may help families understand why siblings can look so different. Keep an eye on future trials that try to boost CD38 or its hormone products—those drugs could one day pair with our behavioral plans.