X-linked mental retardation with a fragile site in Xq and an inversion of chromosome no. 9

The second black male with X-linked mental retardation and a fragile site at Xq27 was ascertained by screening for macroorchidism. GTG banding revealed the presence of an inv(9)(p13q21). This inversion is thought to be a chance occurrence and is probably of no clinical significance. More cases having a marker Xq and a chromosome abnormality are expected; some of these abnormalities will be clinically significant.