A. Ao et al., PREIMPLANTATION GENETIC DIAGNOSIS OF CYSTIC-FIBROSIS (DELTA-F508), European journal of obstetrics, gynecology, and reproductive biology, 65(1), 1996, pp. 7-10
Cystic fibrosis is a common autosomal recessive condition caused by mu
tations in the cystic fibrosis transmembrane regulator gene. The major
mutation is a three base pair deletion (Delta F508). If both partners
carry this deletion, the chance of having an affected child is 1 in 4
. In vitro fertilization (IVF) with preimplantation genetic diagnosis
allows the selection of the unaffected embryos only to be returned to
the uterus. Preimplantation genetic diagnosis was attempted in 14 coup
les in which both partners carry the Delta F508 deletion. A total of 2
2 cycles resulted in 170 normally fertilized embryos of which, 145 emb
ryos were successfully biopsied and in 18 cycles, one or two unaffecte
d embryos were transferred. A total of five clinical pregnancies estab
lished and at birth all five singletons have been confirmed as homozyg
ous for the normal allele. From our experience, cleavage stage biopsy
after in vitro fertilization provides sufficient embryos diagnosed as
unaffected for transfer in this autosomal recessive disease. Also, pre
gnancy rates after the preimplantation diagnosis are similar to those
with infertile couples. Prospects for applying preimplantation genetic
diagnosis to autosomal dominant conditions, where incidences of havin
g affected embryos would be higher, therefore, appear good.