Fragile X regulation is a finely tuned machine
A PNAS paper recently published demonstrates the kinds of insights that can be gleaned from a large scale sequencing project examining the fragile X gene.
Most children (boys, usually) who have fragile X syndrome have a particular mutation. An expanded “triplet repeat” stretch of DNA, which is outside the protein-coding region of the gene, puts the entire gene to sleep.
At Emory, geneticist and a faculty member of the GMB and NS programs, Steve Warren; cell biologist and a faculty member of the BCDB and MS programs, Gary Bassell; and colleagues have been identifying less common changes in the fragile X gene by looking in boys who are developmentally delayed, but don’t have the triplet repeat expansion. The first author of the paper is former postdoc Joshua Suhl, now at Booz Allen Hamilton in Massachusetts.
The authors describe two half-brothers who have the same genetic variant, which changes how production of the FMRP protein is regulated. These examples show that the fragile X gene is so central to how neurons function that several kinds of genetic glitches in it can make this finely tuned machine break down.