Association between MTHFR C677T variant and risk for congenital heart defects in Egyptian children: a case–control study including meta-analysis based on 147 cases and 143 controls

Egyptian Journal of Medical Human Genetics

Table 3 The detailed characteristics of cases in the eligible studies

Author/participants	Year	CASES					CONTROL					HWE test*
Author/participants	Year	CC	CT	TT	C	T	CC	CT	TT	C	T	Chi-square	P value**
El-Abd et al./Mixed***	2012	7	12	7	26	26	13	5	0	31	5	0.47	0.49
Zidan et al./Mixed	2013	18	21	41	57	103	32	21	27	85	75	17.04	0.000
Kotby et al./ CHD****	2012	12	14	4	38	18	20	8	2	48	12	0.852	0.653
The current study/Mixed	2021	42	41	8	125	57	55	34	6	144	46	0.046	0.977
Pooled studies *****	–	61	67	19	189	105	88	47	8	223	63	0.250	0.882

*Hardy–Weinberg equilibrium (HWE) in controls was assessed using a Chi-square goodness of fit test
**P ≤ 0.05 considered statistically significant. The bold p values are significant as appeared
***“Mixed” means that the authors' subjects include conotruncal heart and cardiac septal defects in one study
****CHD refers here to Conotruncal Heart Defect
*****The pooled study includes all except Zidan et al. study