Table 2.

Negative cases of the NIPST using modified ARMS RT- PCR for the detection of PIBTM in maternal plasma cell-free DNA in the at-risk couples.

Couple No.	Maternal mutation	Paternal mutation	Gestation age (week)	Paternal ARMS test	ARMS results	Postnatal diagnosis
1	CD17 A→T	CD26 G→A	16	CD26	NEG	CD17 trait
2	IVS1-1 G→T	CD26 G→A	16	CD26	NEG	Normal
3	-28 A→G	CD26 G→A	10	IVS1-1	NEG	-28 trait
4	CD17 A→T	CD26 G→A	10	CD41/42	NEG	Unaffected
5	CD26 G→A	CD41/42 –CTTT	18	CD41/42	NEG	Normal
6	CD26 G→A	CD41/42 –CTTT	11	CD41/42	NEG	Unaffected
7	CD41/42 –CTTT	-28 A→G	18	CD17	NEG	Unaffected
8	CD17 A→T	CD26 G→A	16	CD41/42	NEG	CD17 trait
9	CD17 A→T	CD26 G→A	19	CD17	NEG	Normal
10	CD41/42 –CTTT	CD17 A→T	13	-28	NEG	CD41/42 trait
11	CD26 G→A	CD41/42 –CTTT	15	CD26	NEG	CD26 trait
12	IVS1-1 G→T	CD26 G→A	16	CD26	NEG	Normal
13	CD41/42 –CTTT	CD26 G→A	16	CD26	NEG	CD41/42 trait
14	CD41/42 –CTTT	CD26 G→A	14	CD26	NEG	Normal
15	CD17 A→T	CD41/42 –CTTT	14	CD26	NEG	Normal
16	CD41/42 –CTTT	CD26 G→A	10	CD41/42	NEG	Normal
17	CD17 A→T	CD26 G→A	7	CD26	NEG	CD17 trait
18	CD26 G→A	IVS1-1 G→T	8	CD26	NEG	CD26 trait
19	CD26 G→A	CD41/42 –CTTT	10	CD26	NEG	CD26 trait

NEG, Negative result; POS, Positive results; Unaffected baby did not determine thalassemia genotype.