Nevertheless, as for autosomal recessive disease, like α-thalassemia, such diagnostic deficiencies will lead to a lower ratio of heterozygote embryos and a reduced number of embryos available for transfer, but homozygous mutant embryos will not be transferred into uterus and lead to any adverse consequences, like Hb Bart’s hydrops fetalis. The gene discussed is GSTM1; the disease is hydrops fetalis.