Prenatal diagnosis and follow up of a child with a complex chromosome rearrangement.

A case of de novo, apparently balanced, three way exchange by translocation plus a pericentric inversion is described. The karyotype is 46,XX,t(6;11)(p21;q21),t(11;21) (q21;p13),inv(6)(p21q11) and was ascertained through second trimester amniocentesis. The structural rearrangements appear balanced. The child was phenotypically normal at birth. Growth and motor development were normal until 30 months, at which time linear growth dropped below the 5th centile. In addition, there was delayed speech development at 2 years of age. As far as we can determine, this is the first report of a three chromosome exchange including a pericentric inversion ascertained through genetic amniocentesis.