Genetic testing may help tailor medications for rare disease patients
Study finds most individuals carry variants affecting drug response
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Genetic testing data collected at diagnosis may help guide medication use in people with rare diseases such as AADC deficiency, a new study shows.
Researchers found that nearly a third of rare disease patients have at least one genetic variation that could influence how their bodies respond to medications they are currently taking. The findings highlight how genetic data may help guide more personalized care.
“In an era where precision medicine is gaining increasing significance, a single [genome sequencing test] could represent a future vision for individualized medicine,” the researchers wrote. The study, “The potential of whole genome sequencing in pharmacogenetics: a retrospective health record study in rare disease patients,” was published in the European Journal of Human Genetics.
How genetic differences can affect medication response
Each person’s genetic makeup can influence how they respond to medications. People with certain genetic variations may process drugs differently, which can affect how well a treatment works and the risk of side effects. This field of study is known as pharmacogenetics.
Pharmacogenetics is still a relatively young field and much remains to be understood. Still, researchers have identified genetic variants that can affect responses to many commonly used medications. Previous studies suggest that most people carry at least one such variant.
People with chronic rare diseases like AADC deficiency often take multiple medications to help manage their condition. These patients also frequently undergo genetic sequencing as part of the diagnostic process. As such, many rare disease patients may have genetic variations that could affect how they respond to the drugs they are taking, with sequencing data already available to help identify these associations.
To explore this, researchers analyzed sequencing data from 1,000 individuals, including people being evaluated for rare diseases and their relatives (none had AADC deficiency specifically). They examined variations in 12 genes known to influence how the body responds to medications and found that nearly all individuals had at least one such variation.
“We [focused] on whole genome data available for rare diseases patients and their relatives, thereby using whole genome data which is already available from different diagnostic procedures and can followingly be used with minimal additional cost,” the scientists noted.
Study finds many patients have actionable gene-drug interactions
In a subset of 359 rare disease patients, the researchers looked for gene-drug pairs — meaning, they compared each patient’s genetic data with the medications they were currently taking. They found that nearly a third of patients had at least one genetic variation that could provide actionable information about a medication they were using, with many patients having more than one.
“In our cohort, actionable variants are considered clinically relevant for almost one-third of the subcohort, as these individuals received a drug for which there was a therapy recommendation (e.g., dose adjustment, drug change or caution during initiation and close monitoring),” the scientists wrote. These data illustrate that pharmacogenetic testing using genetic sequencing data can provide “substantial benefits” for rare disease patients, the researchers added.
