Methylenetetrahydrofolate reductase and transcobalamin genetic polymorphisms in human spontaneous abortion: biological and clinical implications

Table 1 Maternal and fetal MTHFR 677T alleles in human spontaneous abortion.

REFERENCE	NUMBER OF PARTICIPANTS CASES/CONTROLS	RESULT
Recurrent spontaneous abortion
Maternal genotypes
Foka et al. [58]	80/100	No risk
Holmes et al. [59]	173/67	No risk
Kumar et al. [56]	24/24	Increased risk
Kutteh et al. [60]	50/50	No risk
Lissak et al. [55]	41/18	Increased risk
Murphy et al. [61]	40/540	No risk
Nelen et al. [53]	185/113	Increased risk
Pihusch et al. [62]	102/128	No risk
Wramsby et al. [63]	84/69	No risk
Non-recurrent spontaneous abortion
Maternal genotypes ^a
Alfirevic et al. [64]	18/44	No risk
Gris et al. [65]	232/464	No risk
Kupferminc et al. [66]	12/110	No risk
Many et al. [67]	40/80	No risk
Martinelli et al. [68]	67/232	No risk
Murphy et al. [61]	24/540	No risk
Spontaneous abortion
Fetal genotypes
Isotalo et al. [69]	161/119	Increased risk ^b
Zetterberg et al. [22]	80/125	Increased risk ^b
Zetterberg et al. [71]	76/114	Increased risk ^c

^aFive of these six studies examined late fetal loss (fetal death after 19 weeks or more of gestation) ^bInteraction between fetal MTHFR 677T and 1298C alleles ^cInteraction between fetal MTHFR 677T and TC 776G alleles

ISSN: 1477-7827