SV40-transformed fragile (X) amniocytes

We report SV‐40 transformation of female and male fragile X [fra(X)] amniocytes. In the transformants, fra(X) (q27.3) was detected in the 7th passage (9 cell generations) in fra(X) female amniocytes. It was conserved until at least the 20th passage (42 cell generations) although the frequency was reduced or became difficult to detect due to karyotypic evolution in the later generations. Similarly, for the male fra(X) amniocyte line, fra(X) was demonstrated at the 2nd passage (3 cell generations) and persisted until at least the 13th passage (29 cell generations). The prolonged period of reproductive potential of these transformed lines ranging from at least 29–42 generations suggests that the cryopreservation of significant quantities of early passage fra(X) transformed amniocytes will assure a reliable and continuous supply of positive control cells. These lines may be used for fra(X) prenatal diagnostic studies thereby improving the ability to quality control the particular fra(X) induction system being used.