The MTHFR 677T Allele May Influence the Severity and Biochemical Risk Factors of Alzheimer’s Disease in an Egyptian Population

Table 1

Genotype distribution and allele frequencies for the MTHFR rs1801133 single nucleotide polymorphism in Alzheimer’s cases and controls.

Group	No. of patients	Genotype; 𝑛 (%)			𝜒^2	P value	Allele frequency; 𝑛 (%)
		C/C	C/T	T/T			C	T
EAD	12	7 (58.3)	3 (25.0)	2 (16.7)	2.00	0.37^a	17 (0.71)	7 (0.29)
LOAD	31	11 (35.5)	14 (45.2)	6 (19.4)	1.02	0.28^b	36 (0.58)	26 (0.42)
AD cases	43	7 (58.3)	17 (39.5)	8 (18.6)	3.99	0.14^c	53 (0.62)	33 (0.38)^d
Controls	32	20 (62.5)	10 (31.2)	2 (6.3)			50 (0.78)	14 (0.22)

Abbreviations. AD: Alzheimer’s disease, EAD: early-onset AD, LOAD: late-onset AD.
^aNo significant difference in genotype distributions between EAD and LOAD cases (P > 0.05).
^bNo significant difference in allele frequencies between EAD and LOAD cases (P > 0.05).
^cNo significant difference in genotypes between AD cases and controls (P > 0.05).
^dSignificant difference in the frequencies of the T alleles between AD cases and controls (OR = 2.22 (95% CI, 1.1–4.6; P = 0.03)).