Three-day HLA gene check before epilepsy and gout drugs that can burn the skin
TL;DR Firstswab is a single-purpose gene test that a neurologist, psychiatrist or gout clinic orders before prescribing carbamazepine, oxcarbazepine, phenytoin or allopurinol. It looks for the HLA variants linked to severe skin reactions and returns a plain answer within days. Patients pay per test, and partner labs run it.
A few cheap, widely used drugs can trigger Stevens-Johnson syndrome, a skin and mucosa reaction that can blind or kill. For carbamazepine, the main genetic warning sign is HLA-B*15:02. In India its frequency swings from 14.2% in a Northeast sample to zero among West Coast Parsis, with a weighted national mean of 2.1%[1].
Hong Kong, Malaysia, Singapore, Thailand, the UK and the US require screening before carbamazepine[2]. India does not.
That's a strange gap for a country with this much variation. A 2025 review of actionable drug-gene pairs for Indian practice lists these HLA variants and notes that adoption here faces real obstacles[3]. The broad gene panels on sale take close to a month[4], which is no use at all when a patient is having seizures this week.
What it does, in regulatory terms - a laboratory genotyping test that supports a doctor's prescribing decision. It does not diagnose disease or choose the drug. Tests run on CDSCO-licensed kits in NABL-accredited partner labs, under the Medical Devices Rules 2017.
The seed pitched personalised pharmacogenomic insights across all drugs, and I've narrowed it right down. Broad panels already exist, and this directory covers heart-drug and chemotherapy genes elsewhere. The HLA allergy genes are where a single result changes a single decision on the same day.
The doctor's clinic gets a cheek-swab kit and a one-page order form. A courier collects the sample, the partner lab genotypes HLA-B15:02, HLA-A31:01 and HLA-B*58:01, and the doctor receives a one-line result with the matching guideline wording. Firstswab also targets the regions where the variant is common first, because Singapore's analysis found blanket testing of Indian patients was not cost-saving[5]. That honesty is part of the pitch to doctors.
The patient pays, usually in cash at the clinic, as with most tests in India. The decision-maker is the prescriber. There's no public Indian price for a stand-alone HLA-B*15:02 test, and the nearest comparison is a 165-drug panel at ₹6,569[4]. Firstswab needs to land well below that to be ordered routinely. Hospital neurology departments and epilepsy programmes are a second buyer, paying per batch.
Regulators abroad keep adding HLA warnings to labels, and the 2025 review gives Indian doctors a local list of actionable genes[3]. A Taiwanese hospital lifted outpatient screening from 23.7% to 55.6% simply by adding a reminder at the point of prescribing[6], which shows the order prompt is the product. India's new digital health records make that prompt easier to place.
No public figure exists for Indian HLA pre-prescription testing. The firmest signal is regional - allele frequencies as high as 14.2% in parts of the Northeast[1]. Next to that, broad pharmacogenomic panels already sell to Indian consumers at about ₹6,500[4]. Treat that as proof people pay for drug-gene tests, not as your market size.
One Indian genomics company sells a broad drug-response panel through a large online pharmacy, with a report in about 27 days[4]. Large diagnostic chains run HLA typing for transplants, which proves the lab capacity exists. Overseas, hospital systems in Taiwan and Singapore run the test as routine. The gap in India is a fast, cheap, single-question test that reaches the neurologist's desk before the prescription is written.
| Difficulty | Moderate (43/100) |
| Starting capital | ₹60 L–1.2 Cr |
| Time to launch | 6–9 months |
The lab work is mature. The hard part is behaviour - getting busy doctors to delay a cheap drug by two or three days, or to start a safer alternative while they wait. You also need sample logistics fast enough to beat that delay, and you must validate kit performance on Indian samples.
Yes. A genetic test is a regulated diagnostic, so the licences sit with the kit and the lab.
Building this outside India? The categories above usually have a local equivalent, so check with your own regulator.
Don't let AI read the genotype or recommend a drug. The lab's validated method produces the result, and the prescribing decision stays with the doctor.
Want to work out the AI layer for Firstswab? Talk to Yash →
Here's what can go south -
I think this is a sensible, narrow diagnostics business for a founder with lab-partnership or medical-sales experience. If you want to build a consumer genomics brand then it's the wrong idea. Prove one thing first - that 20 neurologists in one high-frequency region will order it for most new carbamazepine starts.
Plan for roughly ₹60 L–1.2 Cr, mostly lab partnerships, kit validation on Indian samples, courier logistics and medical sales.
Yes. The kit must be CDSCO-licensed under the Medical Devices Rules 2017 and the test must run in a NABL-accredited lab with it in scope, plus DPDP consent for genetic data.
Yes, but check how common the variants are locally first, since the economics depend on it. Lab and device rules also differ by country.
The free Firstswab validation kit has the line-by-line capital breakdown, the effort scoring, the lab and data-protection checklist, a 14-day validation sprint with pass/fail targets, a 90-day launch plan, 10 interview questions for doctors and patients, and 5 assumptions to test. Download the kit →
Thinking about building Firstswab or something close to it? The make-or-break work is a turnaround short enough that neurologists will wait for it. If you need a hand, you know where to find me. Talk to Yash →
For illustration only. Names are fictional and ideas hypothetical; sourced facts are real but may be out of date. Nothing here is legal, financial or professional advice, and Yash Khatri is not personally liable for any use of it. Read the full disclaimer.