Researchers from four laboratories that perform diagnostic genetic
testing of chromosome abnormalities in individuals with unexplained
physical and developmental disabilities recently identified a previously
unrecognized genetic disorder.
“In a substantial proportion of children with mental retardation and
developmental delays, the genetic basis is unknown”
In their study, published in the American
Journal of Human Genetics, researchers at Signature Genomic
Laboratories, Nationwide Children’s Hospital, Emory University School of
Medicine and Baylor College of Medicine independently identified a total
of seven individuals with nearly identical-sized deletions, or missing
sections of DNA, on one of their two copies of chromosome 17. None of
the children’s parents had the section of DNA missing, which suggests
the anomaly is causative of the children’s physical and developmental
disabilities which included a combination of developmental delays
including speech delay, postnatal growth retardation, heart defects and
hand, foot and limb abnormalities.
The researchers estimate the incidence of this genetic abnormality in
the general population to be approximately 1 in 115,000.