The Progress of Research on Genetic Factors of Recurrent Pregnancy Loss

Table 1

Summarize the possible factors affecting RPL in gene mutations and gene polymorphisms.

Genes with different functions	Type	Functions	Genes/gene polymorphisms associated with RPL	Reference
Angiogenesis-related genes	VEGF	Stimulation of trophoblast proliferation, development of embryonic vasculature	Polymorphisms of rs1570360, rs3025039, rs2010963 and rs3025020	[22]
			The 1612G > A and 1725G > A polymorphisms in the VEGF 3′-UTR	[23]
	NOS	Increases vascular permeability	894G/T	[26, 27]
			−786T > C	[28]
			12862A > G; Glu298Asp; Intron 4 VNTR	[29]
Genes related to thrombosis	MTHFR	Maintenance of low plasma homocysteine levels	C677TT	[30, 31, 33]
	F V	Blood clotting	G1691A	[30, 31, 33]
	FII	Blood clotting	G20210A G/A	[30, 31, 33]
	PAI-1	Fibrinolysis	−675G/A (4G/5G);−844G/A	[30, 31, 34]
Immune-related genes	PD-1/PD-L1	T-cell immune response and immune homeostasis	PD-1/PDL-1 abnormal increase	[38–43]
	NKs	Induced immune tolerance in fetal mothers	KIR3DL1; KIR2DS2; KIR2DS3	[44, 45, 48]
	HLA	Induced immune tolerance in fetal mothers	HLA-DQ2/DQ8Polymorphism	[49, 50, 52]
Gene polymorphism of estrogen receptor gene	ESR1	Maintaining a successful pregnancy	rs2234693	[60, 63]
			rs3020314	[60, 70]
	ESR2	Maintaining a successful pregnancy	rs2077647A; rs4986938G; rs1256049T	[60, 61]
Inflammation-associated gene polymorphisms	SERPINA4	The body responds to injury or infection	rs20707777AA; rs910352T	[71]
	FAU	The body responds to injury or infection	rs769440	[72]
MMPs	MMP2	Helps implantation and stabilizes the placenta	MMP2-735T	[73–77]
	MMP9	Helps implantation and stabilizes the placenta	MMP9-1562T	[73–77]
ATPase-related genes		ATP synthesis, substance transport	ATP 6V1G3	[78]
Genes associated with oxidative stress	GST	Prevents oxidative damage	GSTA1-69C/T polymorphism	[80, 86, 87]
Genes associated with rhythm		Maintaining normal physiological functions of the body	ARNTL; Npas2	[94, 96, 97]
			ARNTL2; CRY2; DEC1; PER3; RORA	[95–97]