The Fragile XE syndrome is distinct but similar to the Fragile X syndrome.
Chromosome location: Xq28 (vs Xq27.3 for Fragile X)
Gene: FMR2 = FRAXE = fragile site, folic acid type, rare, fra(x)(q28) E
Cause: expanded CCG repeats
Most affected patients are male.
Clinical features:
(1) mild mental retardation (less severe than seen with Fragile X)
(2) autism
(3) variable physical features
