Genetic Polymorphisms Involved in Folate Metabolism and Maternal Risk for Down Syndrome: A Meta-Analysis

Table 1

Characteristics of the included studies in meta-analysis.

First author	Year	Ethnicity	DSM^a	CM^b	Polymorphisms studied and included in meta-analysis	Genotype analysis
Hobbs et al. [25]	2000	Caucasian	145	139	MTRR c.66A>G	PCR/RFLP
O'Leary et al. [26]	2002	Caucasian	48	192	MTRR c.66A>G	PCR/RFLP
Chango et al. [27]	2005	Caucasian	119	120	MTRR c.66A>G/MTR c.2756A>G/CBS c.844ins68	PCR/RFLP
da Silva et al. [28]	2005	Brazilian	154	158	MTRR c.66A>G/MTR c.2756A>G/CBS c.844ins68	PCR/RFLP
Scala et al. [29]	2006	Caucasian	93	257	MTRR c.66A>G/MTR c.2756A>G/CBS c.844ins68/MTHFD1 c.1958G>A	PCR/RFLP
Wang et al. [30]	2008	Asian	64	70	MTRR c.66A>G	PCR/RFLP
Santos-Rebouças et al. [31]	2008	Brazilian	103	108	MTRR c.66A>G	PCR/RFLP
Ribeiro [32]	2008	Brazilian	200	340	MTRR c.66A>G/MTR c.2756A>G/TC2 c.776C>G/MTHFD1 c.1958G>A	PCR/RFLP
Fintelman-Rodrigues et al. [33]	2009	Brazilian	114	110	MTR c.2756A>G/CBS c.844ins68/TC2 c.776C>G	PCR/RFLP
Urpia [34]	2009	Brazilian	61	102	MTRR c.66A>G	PCR/RFLP
Pozzi et al. [35]	2009	Caucasian	74	184	MTRR c.66A>G	PCR/RFLP
Coppedè et al. [36]	2009	Caucasian	81	111	MTRR c.66A>G	PCR/RFLP
Brandalize et al. [37]	2010	Brazilian	239	197	MTRR c.66A>G/MTR c.2756A>G/CBS c.844ins68	PCR/RFLP
Neagos et al. [38]	2010	Asian	26	46	MTHFD1 c.1958G>A	PCR/RFLP
Zampieri et al. [39]	2012	Brazilian	105	185	MTRR c.66A>G/MTR c.2756A>G/CBS c.844ins68/TC2 c.776C>G/MTHFD1 c.1958G>A	PCR/RFLP
Coppedè et al. [40]	2013	Caucasian	286	305	MTR c.2756A>G	PCR/RFLP
Liao et al. [41]	2014	Asian	76	115	TC2 c.776C>G/MTHFD1 c.1958G>A	PCR/RFLP

DSM: case mothers.
CM: controls mothers.