Q: Can a person inherit Schmorl's nodes in the spine? My adult children and I all have these on X-rays.
A: Schmorl's nodes represent a herniation of the disc material into the adjacent endplate. These defects often occur when there is disc degeneration (tears in the disc or thinning of the disc with narrowing of the disc space).
The endplate is a thin layer of cartilage sandwiched between the disc and the vertebral bone above or below it. On imaging studies Schmorl's nodes look like small hollowed areas. Despite many studies on disc herniations and Schmorl's nodes, no one really knows for sure what causes the disc to fracture the endplate like this.
Perhaps there are nutritional reasons. Disc degeneration with age might come with a decrease in blood supply to the area and subsequent loss of nutrition to the disc and the endplates. Your suggestion that there might be a genetic link has also been studied and there is some evidence that heredity may be a contributing factor.
People with a spinal condition called Scheuermann's disease often develop Schmorl's nodes. Scheuremann's has a genetic component. The spine starts to curve forward putting pressure on the front of the vertebral bodies. the thoracic spine (middle of the back) is affected with narrowing of the disc spaces and Schmorl's nodes.
An orthopedic surgeon is the best one to put a finger on why all three of you have schmorl's nodes and advise you what to do about it. Because it is linked with disc degeneration, early diagnosis and treatment are advised.
Reference: Florence P. S. Mok, MSc, et al. ISSLS Prize Winner: Prevalence, Determinants, and Association of Schmorl Nodes of the Lumbar Spine with Disc Degeneration. In Spine. October 1, 2010. Vol. 35. No. 21. Pp. 1944-1952.