With the help of more than 100 clinical collaborators around the world, Friedhelm Hildebrandt, MD has received thousands of blood samples from patients with nephrotic syndrome. They have helped Hildebrandt’s lab determine several underlying causes of this serious kidney disorder, in which high levels of protein are expelled in the urine.

“Nephrotic syndrome is not one disease; in fact, we already know that it is 55 different diseases,” says Hildebrandt, chief of the Division of Nephrology at Boston Children’s Hospital.

Over the course of time, Hildebrandt’s lab has discovered 35 of the more than 55 genes that can cause nephrotic syndrome. Identifying the different genetic pieces of the puzzle can help tailor a precision medicine approach to treating patients.

The latest piece, published earlier this month in Nature Genetics, is a set of four single-gene mutations that cause Galloway-Mowat syndrome (GAMOS) a rare disorder causing early-onset nephrotic syndrome and, often, microcephaly (abnormally small head size). Until now, the genetic changes underlying GAMOS and why they affect two disparate organs — the brain and kidney — have not been well understood.  …