A new glucose-6-phosphate dehydrogenase variant G6PD Sugao (826C-->T) exhibiting chronic hemolytic anemia with episodes of hemolytic crisis immediately after birth

Glucose-6-phosphate dehydrogenase (G6PD) mutations database: review of the "old" and update of the new mutations

In the present paper we have updated the G6PD mutations database, including all the last discovered G6PD genetic variants. We underline that the last database has been published by Vulliamy et al. [1] who analytically reported 140 G6PD mutations: along with Vulliamy's database, there are two main sites, such as http://202.120.189.88/mutdb/ and www.LOVD.nl/MR, where almost all G6PD mutations can be found. Compared to the previous mutation reports, in our paper we have included for each mutation some additional information, such as: the secondary structure and the enzyme 3D position involving by mutation, the creation or abolition of a restriction site (with the enzyme involved) and the conservation score associated with each amino acid position. The mutations reported in the present tab have been divided according to the gene's region involved (coding and non-coding) and mutations affecting the coding region in: single, multiple (at least with two bases involved) and deletion. We underline that for the listed mutations, reported in italic, literature doesn't provide all the biochemical or bio-molecular information or the research data. Finally, for the "old" mutations, we tried to verify features previously reported and, when subsequently modified, we updated the specific information using the latest literature data.

Glucose-6-phosphate dehydrogenase (G6PD) mutations and haemoglobinuria syndrome in the Vietnamese population

Background

In Vietnam the blackwater fever syndrome (BWF) has been associated with malaria infection, quinine ingestion and G6PD deficiency. The G6PD variants within the Vietnamese Kinh contributing to the disease risk in this population, and more generally to haemoglobinuria, are currently unknown.

Method

Eighty-two haemoglobinuria patients and 524 healthy controls were screened for G6PD deficiency using either the methylene blue reduction test, the G-6-PDH kit or the micro-methaemoglobin reduction test. The G6PD gene variants were screened using SSCP combined with DNA sequencing in 82 patients with haemoglobinuria, and in 59 healthy controls found to be G6PD deficient.

Results

This study confirmed that G6PD deficiency is strongly associated with haemoglobinuria (OR = 15, 95% CI [7.7 to 28.9], P < 0.0001). Six G6PD variants were identified in the Vietnamese population, of which two are novel (Vietnam1 [Glu³Lys] and Vietnam2 [Phe⁶⁶Cys]). G6PD Viangchan [Val²⁹¹Met], common throughout south-east Asia, accounted for 77% of the variants detected and was significantly associated with haemoglobinuria within G6PD-deficient ethnic Kinh Vietnamese (OR = 5.8 95% CI [114-55.4], P = 0.022).

Conclusion

The primary frequency of several G6PD mutations, including novel mutations, in the Vietnamese Kinh population are reported and the contribution of G6PD mutations to the development of haemoglobinuria are investigated.