G6PD deficiency
Glucose-6- dehydrogenase (G6PDD), also known as favism, is the most common deficiency worldwide. It is an inborn error of that to red blood cell breakdown. Most of the time, those who are affected have no symptoms. Following a specific trigger, symptoms such as yellowish skin, dark urine, shortness of breath, and feeling tired may develop. can include anemia and newborn . Some people never have symptoms.
Underlined words are explained — tap any of them.
Symptoms — what it feels like
- ·Yellowish skin, dark urine, shortness of breath
Causes — why it happens
- · ( )
Treatment
- ·Avoiding triggers, medications for , stopping offending medication, blood
Complications
- ·, newborn
How common each gene variant is, by ancestry
The share of people carrying the effect version of each variant. South Asian is highlighted; where it differs from European, a risk model built on Europeans can misread it.
Effect-allele frequencies. All-India is the pooled large-sample number from GenomeIndia (≈10,000 Indian genomes); the South-Asian row is the smaller 1000 Genomes phase-3 panel, kept for finer per-subpopulation resolution.
The sections below are general education drawn from public guidelines (NHS, Mayo, CPIC, WHO, ICMR). They are not individually reviewed by a clinician and are not medical advice — always talk to a doctor about your own health.
When to see a doctor
See a doctor if you or your child suddenly become pale, very tired, or short of breath, or notice yellowing of the eyes or dark-coloured urine, especially after an infection, certain foods (like fava beans), or a new medicine. This inherited condition can cause red blood cells to break down.
Get urgent care for deep yellowing of the skin or eyes, very dark or red-brown urine, fast breathing, a racing heart, or extreme weakness. In a newborn, seek prompt care for strong yellowing (jaundice).
General guidance, not a diagnosis. When in doubt, see a doctor.
Questions to ask your doctor
- ?Which blood test confirms this?
- ?Which foods, medicines, and chemicals should we avoid?
- ?Should other family members be tested?
- ?What early signs mean red blood cells are breaking down?
- ?What should I tell other doctors or pharmacists before any new medicine?
- ?How is this monitored over time?
What to note before your visit
- ·what triggered past episodes (food, illness, or medicine)
- ·any pale skin, yellow eyes, or dark urine
- ·family history of this condition
- ·a list of all medicines and supplements taken
Genes that change how certain drugs work — and that differ in South Asians. This is education, not a dosing tool; genotype-guided prescribing is a clinician decision.
Some people are born with red blood cells that can't handle certain 'stressful' medicines. Give those drugs and the red cells burst, causing sudden . A simple blood test tells the doctor whether a drug like an anti-malaria pill is safe for that person.
South Asian signal: G6PD deficiency is common across India: an all-India systematic review found an overall ~1.9% prevalence (range 0.8-6.3%), but tribal/vulnerable groups run far higher - ~7.7% overall in tribal communities and up to ~27% in some groups. The G6PD Mediterranean (563C>T) variant, a severe (Class II) variant, is the commonest deficient allele in India (~60% of deficient cases), so many Indian deficients are the high-risk severe type.
Prescriber note: Screen for G6PD status before prescribing primaquine/tafenoquine (radical cure of vivax malaria), dapsone, or rasburicase; rasburicase is contraindicated in G6PD deficiency. Because the severe Mediterranean variant predominates in India, do not assume mild African-type deficiency. CPIC advises that in G6PD-deficient individuals, drugs with haemolytic potential (e.g. rasburicase - formally contraindicated; primaquine, dapsone, and other listed oxidants) should be avoided or used only with explicit risk-benefit justification and monitoring, and that higher-risk ancestries be screened before such drugs.
Not a dosing tool. Genotype-guided prescribing is a clinician decision; genotyping access in India is limited.
Myths vs facts
Across the other high- (india) gene set (), 17 -'' are actually seen in South Asians () - many European-absent and still clinically 'uncertain'. For g6pd , that's a pool of computationally-damaging, India-relevant, clinically-unresolved variants no one has systematically characterised.
A study that would help: Take the South-Asian-observed, European-absent, ClinVar-uncertain in and them for g6pd : functional or family segregation to move them from 'uncertain' to a real call. Each is a usable diagnostic result.
The enzyme flaw that turns a routine malaria cure into an emergency — with India-only variants the reference data misses
affects about 1.9% of Indians (up to ~6% in some groups). The catch: , the drug that clears relapsing P. vivax malaria, triggers dangerous red-cell breakdown in deficient people — so India's malaria-elimination push runs straight into a wall.
India's malaria- zones overlap its tribal belts, which carry both the most malaria and the most . And the are partly India-specific — Orissa and Kalyan-Kerala alongside the Mediterranean type. Crucially, the urban South-Asian samples in global reference panels () largely miss these tribal variants: a blind spot inside the blind spot.
The major are catalogued, and point-of-care testing before is the known safeguard. The gap is coverage: tribal and India-specific variants are under-represented in reference data, so a 'normal' result can still miss real .
Sequence across under-sampled Indian tribal populations, map the India-specific , and validate whether standard tests catch them before radical-cure is given.
- Molecular spectrum of G6PD deficiency in Indian populations, Blood Cells Mol Dis 2020 ↗
- Haemoglobinopathies & G6PD in vulnerable tribal groups, Odisha (malaria-endemic), 2022 ↗
- D2I2 rare-pathogenic South-Asian scan; the tribal-sampling gap is itself a flagged whitespace