Table 2. Detection of paternally inherited HBB mutations in maternal plasma
HBB mutation
Maternal plasma analysis
Case CD 41/42 (-CTTT) IVS2 654 (C → T) nt — 28 (A → G) CD 17 (A → T) Standard protocol SABER Fetal genotype Weeks gestation
1 F M Neg Neg */* 11
2 F M Neg Neg */* 18
3 F M Neg Neg */* 21
4 M F Pos Pos F/* 18
5 M F Neg Pos F/M 17
6 F M Pos Pos F/* 11
7 F M Pos Pos F/* 14
8 F Neg Neg */* 7
9 F Neg Pos F/* 12
10 M F Neg Neg */* 17
11 F Pos Pos F/* 20
12 M & F N.A. N.A. */* 18
  • All of the parents are carriers for β-thalassemia and have one HBB mutation. The maternal mutation is not indicated for cases where the maternal mutation is not one of the four HBB mutations studied. F and M, mutations of the father and mother, respectively; —, no mutation; Neg, negative; Pos, positive; N.A., not applicable.

  • The fetal genotype determined by conventional methods is indicated by the inheritance of the paternal mutation F, the maternal mutation M, or the normal allele, *