PREIMPLANTATION GENETIC DIAGNOSIS FOR SPINAL MUSCULAR ATROPHY TYPE I (abstract)

This abstract corresponds to the manuscript published in the September 1999 journal Neurology.

L. Fallon, MS (1,4); G.L. Harton, BS (1); M.E. Sisson, BS (1); E. Rodriguez, BS (1); L.K. Field, BS (1); E.F. Fugger, PhD (1,2); M Geltinger, BS (1); Y. Sun, PhD (1); A. Dorfmann, MS (1); C Schoener, RNC, MS (1); D. Bick, MD (1,2); J. Schulman, MD (1,2,3); G. Levinson, PhD (1,3); and S.H. Black, MD (1,2)

1 Genetics & IVF Institute, 3020 Javier Road, Fairfax, VA 22031 USA,
2 Department of Obstetrics and Gynecology, and
3 Department of Human Genetics, Medical College of Virginia, Richmond, VA, USA
4 To whom correspondence should be addressed

Article abstract-- Objective: Couples with children who have spinal muscular atrophy type I (SMA) face a 25% risk of having affected offspring with spontaneous conception. Preimplantation genetic testing (PGT) is possible for the deletions in the survival motor neuron (SMN) gene that have been identified in 98% of SMA type I cases. PGT would provide new reproductive options for families at risk for SMA. Methods: Three couples with previously affected children confirmed by DNA testing each underwent in vitro fertilization (IVF) and PGT of the resulting embryos. One or two blastomeres were biopsied from each embryo and analyzed for deletions in exons 7 and 8 of the SMN gene. Results: Nine embryos were predicted to be unaffected, three to be affected, and one embryo could not be interpreted. One of the three patients receiving transfer of unaffected embryos became pregnant with twins. Conclusions: Preimplantation genetic testing provides a means for couples at risk for spinal muscular atrophy type I to reduce their chance of initiating an affected pregnancy. 

Key words: Spinal muscular atrophy--Preimplantation genetic testing---PCR---SMN gene. NEUROLOGY 1999;53: 1087-1090