Bard's Gallery
G6PD缺乏症
G6PD缺乏症的危害
G6PD缺乏症,全称叫做葡萄糖-6-磷酸脱氢酶缺乏症(Glucose-6-phosphate dehydrogenase deficiency),俗称蚕豆病或者胡豆病.这是一种来自X染色体的遗传性酶缺乏症.
G6PD是一种存在於人体红血球内,协助葡萄糖进行新陈代谢之酵素,在这代谢过程中会产生NADPH的物质能以保护红血球免受氧化物质的威胁.G6PD缺乏时,若身体接触到具氧化性的特定物质或服用了这类药物,红血球就容易被破坏而发生急性溶血反应.
G6PD缺乏症造成的异常溶血,主要有以下几种危害:
- 加重新生儿黄疸
- 可由以下情况造成急性溶血:
- 生病(尤其是感染)
- 某些药物
- 某些食物,尤其是蚕豆
- 某些化学成分
- 糖尿病酮症酸中毒
- 严重情况可能出现急性肾衰竭
基因追溯
| Table 1. Descriptive mutations and variants | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Variants or mutations | Gene | Protein | |||||||
| Designation | Short name | Isoform G6PD-Protein |
OMIM-Code | Type | Subtype | Position | Position | Structure change | Function change |
| G6PD-A(+) | Gd-A(+) | G6PD A | +305900.0001 | Polymorphism nucleotide | A→G | 376 (Exon 5) |
126 | Asparagine→Aspartic acid (ASN126ASP) | No enzyme defect (variant) |
| G6PD-A(-) | Gd-A(-) | G6PD A | +305900.0002 | Substitution nucleotide | G→A | 376 (Exon 5) and 202 |
68 and 126 |
Valine→Methionine (VAL68MET) Asparagine→Aspartic acid (ASN126ASP) |
|
| G6PD-Mediterranean | Gd-Med | G6PD B | +305900.0006 | Substitution nucleotide | C→T | 563 (Exon 6) |
188 | Serine→Phenylalanine (SER188PHE) | Class II |
| G6PD-Canton | Gd-Canton | G6PD B | +305900.0021 | Substitution nucleotide | G→T | 1376 | 459 | Arginine→Leucine (ARG459LEU) | Class II |
| G6PD-Chatham | Gd-Chatham | G6PD | +305900.0003 | Substitution nucleotide | G→A | 1003 | 335 | Alanine→Threonine (ALA335THR) | Class II |
| G6PD-Cosenza | Gd-Cosenza | G6PD B | +305900.0059 | Substitution nucleotide | G→C | 1376 | 459 | Arginine→Proline (ARG459PRO) | G6PD-activity <10%, thus high portion of patients. |
| G6PD-Mahidol | Gd-Mahidol | G6PD | +305900.0005 | Substitution nucleotide | G→A | 487 (Exon 6) |
163 | Glycine→Serine (GLY163SER) | Class III |
| G6PD-Orissa | Gd-Orissa | G6PD | +305900.0047 | Substitution nucleotide | C→G | 131 | 44 | Alanine→Glycine (ALA44GLY) | NADP-binding place affected. Higher stability than other variants. |
| G6PD-Asahi | Gd-Asahi | G6PD A- | +305900.0054 | Substitution nucleotide (several) | A→G ± G→A |
376 (Exon 5) 202 |
126 68 |
Asparagine→Aspartic acid (ASN126ASP) Valine→Methionine (VAL68MET) |
Class III. |
分类
世界卫生组织把G6PD缺乏症分为五类,其中只有前三类是有症状的:
- Class I: Severe deficiency (<10% activity) with chronic (nonspherocytic) hemolytic anemia
- Class II: Severe deficiency (<10% activity), with intermittent hemolysis
- Class III: Mild deficiency (10-60% activity), hemolysis with stressors only
- Class IV: Non-deficient variant, no clinical sequelae
- Class V: Increased enzyme activity, no clinical sequelae
治疗
最主要的方法是避免触发溶血情况.如果触发,可能需要输血或者透析(如果出现急性肾衰竭的情况).