A child with protruding/enlarged abdomen or repeated infections or low weight for age and height or difficulty in walking, running and climbing is usually suspected to have common ailments like infections, malnutrition, worm infestations, and many other common disorders.
In most clinics, these signs point towards conditions doctors encounter every day. And most of the time, that instinct is right. But occasionally, what appears routine is the first clue to something far less familiar.
That is the challenge of rare diseases.
They seldom announce themselves through dramatic or unmistakable symptoms. Instead, they often begin with complaints like fatigue, muscle weakness, repeated infections, low blood counts, delays in attaining developmental milestones (head holding, rolling, sitting) or abnormalities involving liver, spleen, heart or nervous system. These symptoms are easily attributed to more common illnesses.
Rare diseases can therefore “hide in plain sight”: A familiar symptom may point to a common illness when seen in isolation, but a persistent or unusual combination of symptoms may tell a very different story. Rare diseases can be difficult to recognise amid the sheer volume of everyday medical cases. From different studies, it has been found that there could be a delay of four to five years before a correct diagnosis is made.
For families, this can mean years of unanswered questions, multiple specialist consultations and repeated investigations before a diagnosis is finally reached. For clinicians, the challenge lies in identifying the small number of patients whose symptoms do not quite fit the usual pattern.
{{/usCountry}}For families, this can mean years of unanswered questions, multiple specialist consultations and repeated investigations before a diagnosis is finally reached. For clinicians, the challenge lies in identifying the small number of patients whose symptoms do not quite fit the usual pattern.
{{/usCountry}}In a country as vast and diverse as India, where many doctors may never encounter certain rare diseases during their careers, that task becomes even more complex.
According to the Indian Organisation for Rare Diseases, 43% of Indian doctors have never encountered a rare disease patient.
India's scale makes this challenge particularly important. Academic estimates, extrapolating a prevalence of roughly 7%, have suggested that 72–96 million Indians could be living with a rare disease. The number should be understood as an estimate rather than a definitive national prevalence figure.
The real issue, therefore, is not to make every physician become a rare-disease specialist but to make specialist aware of the signs and symptoms of rare conditions.
Rare disease diagnosis is, in many ways, a problem of recognising patterns across information and connecting several seemingly unrelated clues. Persistent thrombocytopenia may not be remarkable on its own. Nor may an enlarged spleen, growth concerns or bone pain. But together, particularly when a patient does not respond as expected to treatment for a common condition, they may warrant an entirely different diagnostic pathway.
AI-enabled clinical support tools are increasingly being designed to analyse symptoms, medical history and available test results together, helping clinicians identify patterns that may otherwise remain fragmented.
One example is AccelRare (www.accelrare.com), a pre-diagnostic platform for physicians, that covers more than 300 rare diseases and has reported diagnostic reliability above 89%, co-developed and validated by 67 rare disease experts across 13 rare disease networks. The platform can assess hundreds of rare diseases, recommend complementary diagnostic investigations and even guide physicians towards government-recognised Centres of Excellence for referral.
The role of such technology is not to make a diagnosis, but to raise informed concerns. Clinical judgement remains central. The value of AI lies in helping ensure that an important possibility is not overlooked simply because it falls outside a physician's day-to-day experience.
For a country as large and diverse as India, that capability could prove especially valuable. Specialist expertise is often concentrated in select institutions, while many patients begin their health care journey elsewhere. Digital decision-support tools offer a way to bridge that gap by extending access to specialist knowledge beyond specialist centres.
Over the past few years, India has steadily strengthened its policy architecture for rare diseases. The National Policy for Rare Diseases, 2021 established a framework spanning prevention, diagnosis, Centres of Excellence, research and access to treatment. The ministry of health and family welfare said the national network had expanded from eight to 15 Centres of Excellence in May 2026, while financial assistance under the policy had been enhanced to ₹5 million one-time support for eligible patients.
The Centres of Excellence provide concentrated expertise. Digital clinical-support systems can help extend the reach of that expertise by enabling a physician elsewhere in the country to recognise when a patient should be investigated further or referred.
That referral moment is critical. In several progressive rare diseases, delays can result in irreversible complications before the underlying condition is identified. Therefore, the biggest opportunity may lie upstream, reducing the time between the first unexplained symptoms and the first informed suspicion.
The biggest contribution AI may make to rare disease care is surprisingly simple: helping clinicians ask the right question earlier on. When symptoms persist despite treatment, when several organ systems appear to be involved, when the clinical course does not behave as expected, or when findings cannot be explained by a single common diagnosis, the question may need to change from “Which common disease is this?” to “Could this be something rare?”
Technology can provide that prompt. But it must sit within a larger ecosystem: greater awareness on rare diseases among health care professionals, validated diagnostic pathways, stronger connections with Centres of Excellence, appropriate genetic and biochemical testing, responsible handling of health data and, above all, clinical judgement.
India does not need every doctor to become a rare disease expert. It needs expertise to be one click away — wherever that doctor happens to be sitting. That is the real diagnostic odyssey worth shortening.
(The views expressed are personal)
This article is authored by Dr Milan Choksey, medical lead, rare diseases, Sanofi (India).