Gene mutation that leads to mental retardation in boys identified

Researchers have found that a subtle mutation affecting the epigenome - a set of dynamic factors that influence gene activity - may lead to an inherited form of mental retardation that affects boys.

The findings may help scientists further understand why X-linked disorders cause cognitive impairment and develop new therapies to treat or prevent them.

Hank Qi and his collaborators, Madathia Sarkissian and Thomas Roberts at Dana-Farber Cancer Institute, tested the normal enzyme function of histone demethylase in zebrafish, a popular model for genetic function.

The team found a dramatic impact on craniofacial development and the fish without the enzyme developed virtually no jawbone.

"These studies suggest that the imbalance of histone methylation dynamics plays a critical role in mental retardation. You can imagine a therapeutic approach to enhance the compromised enzymatic activity or to restore the downstream function," says Yang Shi, also a professor of pathology at Harvard Medical School.

The study is published online July 11 in the journal Nature.