Question 1

What is a rare disease?

Accepted Answer

A rare disease is any medical condition affecting a relatively small proportion of the population — defined by each jurisdiction (EU: fewer than 5 in 10,000; US: fewer than 200,000 people; Japan: fewer than 50,000). Despite individual rarity, there are 7,000+ recognised rare diseases collectively affecting 300 million people. The term "orphan disease" comes from the pharmaceutical industry's historical neglect of developing treatments for small patient populations.

Question 2

Are rare diseases always genetic?

Accepted Answer

Approximately 80% of rare diseases have a genetic basis — single-gene disorders (like phenylketonuria, cystic fibrosis, Huntington's disease) or chromosomal abnormalities. The remaining 20% include rare infections, rare cancers, rare autoimmune and inflammatory conditions and rare environmental diseases. The genetic basis of most rare diseases makes genomic sequencing (whole exome or genome) the most powerful diagnostic tool available.

Question 3

What is the diagnostic odyssey?

Accepted Answer

The diagnostic odyssey is the lengthy, frustrating process of reaching a correct diagnosis for a rare disease — averaging 5-7 years, during which patients typically see 8 or more physicians, receive multiple incorrect diagnoses and inappropriate treatments. The odyssey is driven by: physician unfamiliarity with rare conditions; non-specific symptoms mimicking common diseases; lack of diagnostic tests; and rarity preventing pattern recognition. Whole exome/genome sequencing is dramatically reducing the diagnostic odyssey for many genetic rare diseases.

Question 4

Why do 95% of rare diseases have no treatment?

Accepted Answer

The market for any individual rare disease is too small to justify standard pharmaceutical development costs ($1-3 billion per drug). Without regulatory incentives, pharmaceutical companies had no commercial reason to invest. The 1983 US Orphan Drug Act changed this — providing 7-year market exclusivity, tax credits, FDA fee waivers and development assistance. This catalysed a transformation: over 700 orphan drugs have been approved since 1983. The EU followed with Regulation 141/2000. Despite progress, the vast majority of rare diseases still have no approved treatment.

Question 5

What are orphan drugs and why are they so expensive?

Accepted Answer

Orphan drugs — medicines for rare diseases — often cost hundreds of thousands to millions of dollars per patient per year. High prices reflect: small patient populations (few units sold to recover development costs); expensive development (often requiring complex biologics or gene therapies); and orphan drug market exclusivity (limited competition). The highest-priced drug ever approved — Hemgenix (haemophilia B gene therapy) — costs $3.5 million per patient. This creates profound access equity challenges even in high-income countries.

Question 6

What is the gene therapy revolution for rare diseases?

Accepted Answer

Gene therapy — delivering corrective genetic material to cells — is transforming treatment of many genetic rare diseases. Approved therapies include: Zolgensma (spinal muscular atrophy — single dose, $2.1 million); Casgevy (sickle cell and thalassaemia — CRISPR-based, $2.2 million); Hemgenix (haemophilia B); Roctavian (haemophilia A); and multiple others. These one-time treatments can be curative for devastating conditions — but their extraordinary costs create major access equity challenges.

Question 7

What are the most common rare diseases?

Accepted Answer

Cystic fibrosis (CF) — about 90,000 people worldwide; Huntington's disease — approximately 30,000-40,000 in US; haemophilia A and B — approximately 400,000 globally; Marfan syndrome — approximately 1 in 5,000; phenylketonuria (PKU) — approximately 1 in 10,000; sickle cell disease (in some definitions); lysosomal storage disorders (Gaucher, Fabry, Pompe, MPS); and rare cancers. Together these "common rare diseases" account for a large proportion of the collective rare disease burden.

Question 8

What is World Rare Disease Day?

Accepted Answer

World Rare Disease Day — held on the last day of February each year (28 or 29 February, reflecting rarity) — is coordinated by EURORDIS and 1,000+ rare disease patient organisations in 100+ countries. It advocates for: equitable access to diagnosis and treatment; research investment; policy change; and social inclusion. The annual theme focuses on different aspects of the rare disease experience. Since 2008, it has grown into the world's largest global awareness campaign for a single health theme.

Question 9

What is Orphanet?

Accepted Answer

Orphanet is the European reference portal for rare diseases and orphan drugs — maintained by INSERM (France) with the support of the European Commission. It provides a database of 7,000+ rare diseases with descriptions, associated genes, epidemiology, patient organisations, diagnostic centres, clinical trials, orphan drug designations and scientific publications. It is the most comprehensive rare disease information resource available globally, accessible free at orpha.net.

Question 10

How does the WHO engage with rare diseases?

Accepted Answer

WHO established a Rare Disease Technical Advisory Group and passed WHA Resolution 72.10 (2019) acknowledging the significant impact of rare diseases. WHO has called for: integrated rare disease policies within national health plans; use of genomics for diagnosis; equitable access to affordable treatments; and international data sharing. WHO's Global Genomics Strategy and the international Beacon network for rare disease data sharing are related initiatives.

Question 11

How does GMJ News cover rare diseases?

Accepted Answer

GMJ News covers WHO rare disease policy, World Rare Disease Day, gene therapy approvals and access challenges, orphan drug legislation and genomics for rare disease diagnosis. Rare disease patients in Georgia — many of whom face even longer diagnostic odysseys and more severe treatment access barriers than in high-income countries — are a direct concern for PHIG and the Georgian Medical Journal.

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