This can also be called small-for gestational age (SGA) or fetal growth restriction. There are basically two different types of IUGR: Symmetric or primary IUGR is characterized by all internal organs being reduced in size. Symmetric IUGR accounts for 20% to 25% of all cases of IUGR.
Fragile X syndrome (FXS), also known as MartinâBell syndrome, or Escalante's syndrome (more commonly used in South American countries), is a genetic syndrome.
Nearly all cases of fragile X syndrome are caused by an alteration (mutation) in the FMR1 gene where a DNA segment, known as the CGG triplet repeat, is expanded. Normally, this DNA segment is repeated from 5 to about 40 times. In people with fragile X syndrome, however, the CGG segment is repeated more than 200 times.