Glucose-6-phosphate dehydrogenase and its relationship to mental retardation

COVID-19 in G6PD-deficient patients, oxidative stress, and neuropathology

Glucose-6-phosphate dehydrogenase (G6PD) is an enzyme that regulates energy metabolism mainly through the pentose phosphate pathway (PPP). It is well known that this enzyme participates in the antioxidant/oxidant balance via the synthesis of energy-rich molecules: nicotinamide adenine dinucleotide phosphate reduced (NADPH), the reduced form of flavin adenine dinucleotide (FADH) and glutathione (GSH), controlling reactive oxygen species generation. Coronavirus disease 19 (COVID-19), induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is considered a public health problem which has caused approximately 4.5 million deaths since December 2019. In relation to the role of G6PD in COVID-19 development, it is known from the existing literature that G6PD-deficient patients infected with SARS-CoV-2 are more susceptible to thrombosis and hemolysis, suggesting that G6PD deficiency facilitates infection by SARS-CoV-2. In relation to G6PD and neuropathology, it has been observed that deficiency of this enzyme is also present with an increase in oxidative markers. In relation to the role of G6PD and the neurological manifestations of COVID-19, it has been reported that the enzymatic deficiency in patients infected with SARS-CoV-2 exacerbates the disease, and, in some clinical reports, an increase in hemolysis and thrombosis was observed when patients were treated with hydroxychloroquine (OH-CQ), a drug with oxidative properties. In the present work, we summarize the evidence of the role of G6PD in COVID-19 and its possible role in the generation of oxidative stress and glucose metabolism deficits and inflammation present in this respiratory disease and its progression including neurological manifestations.

Cognitive function in patients with chronic granulomatous disease: a preliminary report

Chronic granulomatous disease is an inherited immunodeficiency in which phagocytes fail to generate superoxide and its metabolites, resulting in severe recurrent infections and frequent hospitalizations. Chronic illness and frequent hospitalizations can affect growth and development as well as social and educational opportunities. Since no data have been reported on cognitive functioning in patients with this illness, the authors sought to examine cognitive function in a group of patients with chronic granulomatous disease. A retrospective chart review of 26 patients seen and followed at the National Institutes of Health who had received cognitive testing at the request of parent or staff was performed. Demographic information including medical, psychiatric, and developmental histories was gathered. Six patients (23%) were found to have an IQ of 70 or below, indicative of cognitive deficits, and all of those patients had defects in the membrane-linked cytochrome b558. The prevalence of cognitive deficits in this selected population of chronic granulomatous disease patients was high. The determination of the true distribution of cognitive functioning in the general chronic granulomatous disease population is important, since cognitive deficits have implications for educational planning and potential therapies such as transplantation and gene therapy in children.

Glucose 6-Phosphate dehydrogenase deficiency genetic, pathophysiological and therapeutic aspects

Glucose 6-phosphate dehydrogenase (G6PD) is the first enzyme of the pentose phosphate pathway. It exists in over 250 variants which are divided broadly into five classes on the basis of residual enzyme activity and clinical manifestations. The variants with reduced activity result in G6PD deficiency. This is inherited as an X-linked recessive disorder and occurs at a much higher frequency in the male than in the female. Most G6PD deficient individuals show no clinical abnormality under normal conditions, but acute hemolytic crisis may occur. Several nonhemolytic abnormalities occur as well in G6PD deficients at a higher frequency than in nondeficients. Several nonhemolytic abnormalities occur as well in G6PD deficients at a higher frequency than in nondeficients. The genetic, pathophysiologic, and therapeutic aspects of G6PD deficiency are presented; and the possibility of genetic counselling, care in blood banks, and benefits of education the G6PD deficients are discussed.

Population screening for glucose-6-phosphate dehydrogenase deficiency on the Baleares

Two thousand people on the Isles of the Baleares were screened for glucose-6-phosphate dehydrogenase deficiency using a commercially available kit. Among the thousand males tested, five were found deficient; of the thousand women, one had low enzyme activity according to this test. Diagnosis of glucose-6-phosphate dehydrogenase deficiency could be verified using hair follicle analysis on mailed hair samples. The same technique also allowed heterozygotes to be identified unequivocally.