Glucose-6-phosphate dehydrogenase deficiency (G6PDd), an X-linked, hereditary and recessive genetic trait, is the most common genetic enzymopathy in humans. Glucose-6-phosphate dehydrogenase (G6PD) is an enzyme catalyzing the first reaction in the pentose phosphate pathway, providing reducing power to all cells in the form of NADPH (nicotinamide adenine dinucleotide phosphate). In red cells, defense against oxidative damage relies only on NADPH generated by G6PD activity [
1]. More than 200 variants and 186 substitutions in the
G6PD gene have been described [
2,
3]. Though mostly asymptomatic, G6PDd may cause red cell membrane damage, haemoglobin crystals, haemolytic anaemia, neonatal jaundice, or haemoglobinuria in cases of induced oxidative stress from nutrition and drugs. Importantly, primaquine is a major anti-malarial treatment. Individuals who have inherited the G6PDd phenotype can exhibit sensitivity to primaquine, which leads to symptoms that range from moderate to lethal depending on the deficiency class [
4,
5], and as such are designated primaquine-sensitive. Clinical relapse due the release of liver hypnozoites is the major characteristic of
Plasmodium vivax and amino-8-quinoline-based primaquine and tafenoquine remain the only effective drugs against this parasitic form to date [
1,
6]. The concordance of the geographical distribution of G6PDd variants with lower levels of parasitaemia and reduced risk of infection led to the hypothesis that this enzymatic feature is selectively advantageous in past and present malarial endemic areas [
7‐
10]. Though the exact mechanisms remain elusive, G6PDd would favour early phagocytosis of parasitized red blood cells at a stage where the parasite has not yet multiplied [
11].
Recently, reviews mapped the state-of-the-art of the G6PD variation evidenced at the enzymatic and molecular levels [
12‐
14]. G6PDd seems restricted to Africa, Southern Europe, Asia, and Pacific islands and virtually absent in the Native American populations of the Americas [
12,
15]. In Latin America, though drug-induced haemolysis represents most of the acute anaemia, only minimal data is available to accurately address the G6PD geographical distribution among non-urban populations [
13]. Most Latin American countries are endemic areas for malarial parasites and transmission vectors [
16]. Even if Mexico, Haiti, and Costa Rica would have eliminated malaria, other countries are still in control phase and require the use of primaquine knowing the risk of haemolysis that may result in G6PD-deficient persons. In Latin America but French Guiana, primaquine is prescribed for every patient infected with
P. vivax without looking for G6PDd or ethnicity assignment [
17]. In French Guiana,
P. vivax has become the dominant malaria species with more than 60 % of attacks with a substantial increase of cases since mid-2001, mostly observed in children [
18], Amerindian populations [
19], gold panners, French armed forces [
20], Hmong [
21], and to a lesser extent, in the Noir Marron community [
22]. Most of the malaria transmission occurs along the two frontier rivers. Along the middle Maroni River—western border with Suriname—
Plasmodium falciparum malaria incidence remains higher than
P. vivax, particularly in the Noir Marron territory. In contrast,
P. vivax is more frequent in the upper reaches of the Maroni River where it infests the Wayana and Emerillon Amerindian populations [
22].
Plasmodium vivax is also preponderant along the eastern border with Brazil, Oyapock River, and in the eastern inland areas. Though part of former anthropological studies [
23‐
25], G6PD genetic variation in French Guiana in relation with malaria risk has never been carried out so far [
22]. This lack of information prevents implementation of efficient programmes for the control or elimination of
P. vivax malaria in Latin America [
13].
The present study aims to partially tackle this issue with original data from a well-defined population from French Guiana assumed to carry sub-Saharan genetic polymorphisms. For this aim, the Noir Marron community which has arisen from the merger of slaves who escaped from Dutch plantations [
26], was investigated. First, validation of the sub-Saharan origin of the red cells was allowed by the frequencies of antigen phenotypes of six membrane genetic systems linked with a sub-Saharan ancestry. At the same time, knowledge of these main red cell antigen frequencies would be crucial for blood product requirements and minimum stock levels to ensure blood transfusion compatible with recipient blood characteristics. Then the main sub-Saharan G6PDd variants indexed in [
2] and assumed to be encountered were screened by molecular biology.