New study sheds light on mysterious infant deaths nearly a century ago—and could help scientists better understand cancer

Now scientists have a better answer as to why.

A partial answer came in 2011, when researchers discovered a condition called infantile hypercalcaemia type 1, caused by a mutation in the CYP24A1 gene. The condition, which occurs when the body can’t metabolize Vitamin D properly, causes calcium to build up in the blood, leading to kidney stones, kidney damage, and potentially death.

The discovery solved the mystery, for the most part. But not everyone apparently affected by the condition had the genetic error—about 10% did not.

A new study from researchers in the United Kingdom reveals why: Patients they studied who have the condition, but who don’t have a mutation on the CYP24A1 gene, have a misshapen CYP24A1 gene, to the same effect, according to an article published Wednesday by United Kingdom researchers in the Journal of Bone and Mineral Research.

“This tells us that gene shape is important in gene regulation—and that this is the reason why some people lived with [the condition] but without a definitive diagnosis,” Dr. Darrell Green, a lecturer in RNA biology at the University of East Anglia’s Norwich Medical School in the United Kingdom and one of the study’s lead authors, said in a news release about the study.

The discovery has wide applicability to the fields of genetics and health at large, according to Green. Scientists already knew that “genes must have the correct sequence to produce the correct protein.”

“But in an added layer of complexity, we now know that genes also have to have a correct physical shape,” he said.

The researchers now plan to study how gene shapes might influence other disorders, like cancer.