Mahajan interviewed by The Scientist

Palo Alto, Ca — Genetic testing doesn’t always provide a diagnosis, so Vinit Mahajan M.D., Ph.D., professor of ophthalmology at Stanford University, has applied proteomics to better understand disease in his patients. 

Proteomics is the large-scale analysis of protein expression, and for over a decade, Mahajan and his team have been using this technology to discover biomarkers, therapeutic targets, and molecular pathways involved in eye diseases where diagnosis is difficult and current treatment is inadequate.

Because of his expertise in clinical proteomics, Mahajan was called upon by The Scientist to comment on Technical University of Berlin researcher Juri Rappsilber’s work described in “Diagnosing Disease with Proteomics”. Rappsilber is one of the senior authors who used proteomics to identify the cause of a rare disease in two pediatric patients whose genetic tests were inconclusive.

“There are many genetic mutations that are not easily detectable when screening the over 10,000 human genes. Rappsilber’s team instead measured protein levels, and the pattern of proteins pointed to a specific gene. Rigorous and detailed DNA analysis of only one gene created a narrow focus, and the mutation was finally identified,” Mahajan said. 

Another common technology is single cell RNA sequencing to study gene expression.

“Interestingly, there was very little overlap between RNA expression and the proteomics data,” Mahajan said. “It really supports the need for adding proteomics to analysis of rare diseases.”   

There are other advantages of using proteomics to understand human disease.

“Genes are static,” said Mahajan. “They don’t tell us when the disease is active, when it’s going to start, when it’s going to stop. For real-time analysis of a patient’s disease state, you need to look at proteins.”

Mahajan believes the next big step in precision health is going to be personalized proteomics. This belief led him to establish the Stanford Molecular Surgery Program and the Stanford Ophthalmology Biorepository where researchers can access patient tissue for proteomics research. 

Mahajan said, “Proteomics is a cutting-edge molecular surgery tool impacting precision health and personalized patient care. Used in concert with genetic testing, it can give a full picture of a patients’ medical condition.”