Stroke
A is a medical condition in which blood flow to a part of the brain is reduced or blocked causing cell death. There are two main types of stroke: , due to lack of blood flow, and , due to bleeding. Both cause parts of the brain to stop functioning properly.
Underlined words are explained — tap any of them.
Symptoms — what it feels like
- ·Facial drooping, inability to walk, move or feel on one side of the body, problems understanding or speaking, dizziness, loss of vision to one side
Causes — why it happens
- · (blockage) and (bleeding)
How it's found
- ·Based on symptoms with medical typically used to rule out bleeding
Treatment
- ·Based on the type
Complications
- ·Persistent state
Outlook
- ·Average life expectancy 1 year
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.
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.
is a 'switched-off' medicine that your body has to switch on using an called . Many South Asians carry a gene version that makes a weaker enzyme, so the drug never fully turns on and does less to stop dangerous - which is why a doctor may pick a different blood thinner instead.
South Asian signal: The loss-of-function alleles CYP2C19*2 (c.681G>A, rs4244285) and *3 (c.636G>A, rs4986893) are common in South Asians. In a British-South Asian clopidogrel cohort, ~13% were poor metabolisers (two LOF alleles) and ~57% carried at least one LOF allele (intermediate or poor) - higher than European (~2.4% PM) reference (JACC Advances 2023, PMC10550831). CYP2C19*2 allele frequency in South Asians is reported around 30-34% (Ionova et al., Clin Transl Sci 2020).
Prescriber note: In a South Asian ACS/PCI patient, a poor response to clopidogrel is more likely than European data suggest; where CYP2C19 genotype or a validated point-of-care test is available, an intermediate/poor metaboliser result supports switching to prasugrel or ticagrelor rather than escalating clopidogrel. For CYP2C19 intermediate or poor metabolisers with ACS/PCI, CPIC recommends avoiding clopidogrel and using an alternative antiplatelet (e.g. prasugrel or ticagrelor) where not contraindicated, because reduced clopidogrel activation raises the risk of major adverse cardiovascular events.
Not a dosing tool. Genotype-guided prescribing is a clinician decision; genotyping access in India is limited.
is famously hard to dose - too little and form, too much and you bleed. Two genes largely decide how much each person needs: one controls how fast you break the drug down, the other how strongly it works. Knowing them helps a doctor get closer to the right dose sooner.
South Asian signal: CYP2C9 and VKORC1 variants together explain up to ~18% and ~30% of warfarin-dose variance respectively in Europeans, but explain proportionally less in Asian ancestry, so ancestry-specific algorithms matter. CYP2C9 and VKORC1 variant frequencies differ across Indian sub-populations; CPIC therefore provides continental-ancestry-specific dosing guidance rather than a single formula (CPIC 2017 update).
Prescriber note: Where CYP2C9/VKORC1 genotype is available, use an ancestry-appropriate validated algorithm (e.g. the CPIC-endorsed approach) for the initial dose and then titrate to INR; do not apply European-derived dose predictions unmodified to South Asian patients. CPIC recommends using a validated pharmacogenetic dosing algorithm that incorporates CYP2C9 and VKORC1 (and, for some ancestries, CYP4F2 and rs12777823) to estimate a starting warfarin dose targeting INR 2-3, rather than a fixed empirical dose, when genotype is available.
Not a dosing tool. Genotype-guided prescribing is a clinician decision; genotyping access in India is limited.
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