Researchers at Baylor College of Medicine have created a population-specific database that sheds light on unique genetic information previously unseen in larger cohorts.
The team, led by Zeynep Coban-Akdemir, focused on a specific population originating from Turkey, known to have distinct genetic variations compared to other European populations. By analyzing exome sequencing data from 773 unrelated individuals affected by various rare Mendelian diseases and 643 unaffected relatives, the team uncovered a remarkable finding: roughly half of the genetic variants in this Turkish group are not present in the larger European control populations commonly used in genetic research.
The study, published in Genetics in Medicine OPEN, revealed a correlation between the occurrence of complex genetic disorders and increased levels of consanguinity, a phenomenon where both parents contribute similar genetic markers to their offspring, often due to a shared common ancestor. The researchers observed that the regions of homozygosity (ROH) on the chromosomes were longer in individuals with a higher degree of parental consanguinity, providing insights into the impact of these genetic variations on disease manifestation.
"We can see what is happening when consanguinity is at play and also when new genetic variations are introduced into the family unit of the clan or tribe representing more distant ancestors," said Dr. Coban-Akdemir.
The researchers further applied statistical methods to systematically assess the impact of these newly introduced genetic variations on disease, revealing that they can better explain the clinical features observed in their patients.
"The published study contributes to the field of both rare disease and population genomics, providing a valuable resource for comprehending fundamental concepts of human genetics and applying diverse computational methods to elucidate these concepts," said co-author Tugce Bozkurt-Yozgatli.