Fallon L, Harton G L, Sisson M E, Rodriguez E, Field L K, Fugger E F, Geltinger M, Sun Y, Dorfmann A, Schoener C, Bick D, Schulman J, Levinson G, Black S H
Genetics & IVF Institute, Fairfax, VA 22031, USA.
Neurology. 1999 Sep 22;53(5):1087-90. doi: 10.1212/wnl.53.5.1087.
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.
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.
Nine embryos were predicted to be unaffected, three to be affected, and one embryo could not be interpreted. One of three patients receiving transfer of unaffected embryos became pregnant with twins.
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.
患有Ⅰ型脊髓性肌萎缩症（SMA）的有子女夫妇自然受孕时，生育患病后代的风险为25%。对于98%的Ⅰ型SMA病例中已确定的生存运动神经元（SMN）基因缺失，植入前基因检测（PGT）是可行的。PGT将为有SMA风险的家庭提供新的生育选择。
三对夫妇先前有经DNA检测确诊患病的子女，每对夫妇都接受了体外受精（IVF）及对所获胚胎的PGT。从每个胚胎中活检一或两个卵裂球，并分析SMN基因第7和8外显子的缺失情况。
预计9个胚胎未受影响，3个受影响，1个胚胎无法判断。三名接受未受影响胚胎移植的患者中有一人怀了双胞胎。
植入前基因检测为有Ⅰ型脊髓性肌萎缩症风险的夫妇提供了一种降低孕育患病胎儿几率的方法。
