"The missing members of these gene families," the researchers suggested, "should be targeted for sequence finishing in order to more accurately capture the architecture and diversity of the human genome."
While duplications of segments of the genome appear to have led to many of the qualities that distinguish human beings from other primate species, areas of the genome in which duplications promote recurrent rearrangements have also been associated with debilitating diseases like intellectual disability, schizophrenia and autism.
The researchers hypothesize, "Extreme variation resulting from duplications may contribute to genomic instability associated with disease."
Overall, the results of the study shows scientists can now leverage newly developed techniques to explore some of the most complex genetic regions of the human genome. Still, a portion of the genome remains impenetrable. About 28 large regions of the human genome have such extraordinary complexity that as yet it is impossible to interpret the underlying pattern of genetic diversity, the authors said.
Despite this limitation, the approaches tested in the study hold promise for improving the understanding of how copy number variation contributes to human health and illness.
"Our approach," the researchers concluded," makes many of the highly duplicated regions of the human genome—and the more than 1,000 previously inaccessible human genes that lie therein—accessible to genetic studies of disease association."