Table 4.
An exhaustive list of Gene polymorphism studies that have reported to affects the plasma level of homocysteine
| S.NO | Gene Symbol | Polymorphism | Amino Acid | Consequences | |
| Homocysteine Level | Gene expression /Enzyme Activity | ||||
| 1 | MTHFR | C677T A1298C A1793G |
A222V E429 A R594Q |
↑ ↑ ↑* |
↓ [140] ↓ N.R |
| 2 | CBS | 31 bp VNTR (exon 13-intron 13) G919A 844Ins68 (Exon 8) T833C |
----- G307S ----- L278 T |
↑**[141–142] ↑ [143–144] ↓ [121] ↑ [120] |
↓ ? [120] ↑ (P) [145] ? [120] |
| 3 | MTR | A2756G | D919G | ↓ [121] | N.R |
| 4 | MTRR | A66G | I22M | ↑ [145] | N.R |
| 5 | MAT | G791A | R264H | NE [146] | ↓ [147] |
| 6 | TYMS | A 28-bp repeat (Enhancer region) A 6-bp deletion (3'UTR) |
-------- ----- |
↑ [124,125] ↓ (del/del) [148] |
Alteration in transcription level[120] ↓ [149] |
| 7 | CTH | G1346T | S403I | ↑ [126] | N.R |
| 8 | GCP II/Folh1 | C1561T | H475Y | ↑ [127,128] | ↓ [128] |
| 9 | RFC-1 | G80A | R26H | NE [129] | N.R |
| 10 | eNOS | G894T T786C (Promoter) CA Repeats (Intron 13) |
E298D --------- --------- |
↑ [150] ↑ [152] ↑ (In female) [154] |
N.E [151] ↓ [153] N.R |
| 11 | TC II | C776G A67G |
P259R I23V |
↑ [130] ↓ [130] |
↓ [155] |
| 12 | APO E | Epsilon4 alleles | -------- | ↑ [156] | N.R |
| 13 | PAI-1 | 4G Ins/del (Promoter) | -------- | ↑ [157] | Affects the response of the PAI-1 promoter to cytokines [158] |
| 14 | F2 | G20210A (3'UTR) | -------- | ↑ [159] | ↑ [160] |
| 15 | Factor V | G1691A | R506Q | ↑ [159] | Impairs APC mediated inactivation of factor Va [161] |
N.R Not reported in the literature
N .E No Effect was observed.
* Border line association was observed in the presence of high folate concentration.
** After post methionine load
(P) Presence of low concentration of pyridoxal -5-phosphate.