Targeted sequencing of the protein-coding regions of the human genome has been used to identify the cause of a rare genetic disorder, as reported online in Nature Genetics.
The protein-coding regions of the genome, or exome, covers about one percent of the human genome can be analyzed at a fraction of the cost of sequencing the entire genome. Michael Bamshad and colleagues sequenced the exome of individuals with Miller syndrome to identify the genetic basis for this rare disorder. Miller syndrome is characterized by facial malformations and limb abnormalities, including cleft palate, incomplete limb development and absence or webbing of certain fingers or toes. Though it was identified 30 years ago, its genetic basis had remained elusive.
To find genetic variants likely to play a role in this disorder, the scientists compared the exome sequences of four affected individuals to typical genetic variation found in public databases and to the exome sequences of eight unrelated and non-affected individuals. This filtering approach identified one candidate gene, DHODH. Further sequencing of this gene in additional individuals with Miller syndrome confirmed a role for DHODH.
DHODH encodes an enzyme that is used to assemble essential building blocks for cells. This classifies Miller syndrome as an inborn error of metabolism caused by mutations in DHODH.
Michael Bamshad (University of Washington, Seattle, WA, USA)
Jay Shendure (University of Washington, Seattle, WA, USA) Abstract available online.
(C) Nature Genetics press release.
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