[The utility of whole genome sequencing in rare disease diagnostics]

If a disease affects fewer than 1 in 2 000, the European Union defines it as a rare disease. Globally, about 300 million people live with a rare disease, and in Sweden about 400 000. There are approximately 7 000 different rare diseases. The clinical picture varies from a single symptom to complex patterns with multiple organs affected, often combined with cognitive and motor impairment. At least 72 % of all rare diseases are genetic and 70% have childhood onset. Many patients are undiagnosed and do not receive optimal treatment. Today, only 5% of rare diseases have an approved treatment option. With modern genetic high throughput techniques, many disease-causing mutations are identified, increasing the possibility of personalized treatment and prevention strategies, designed by the individual's genetic conditions, i.e. precision medicine.