12. Rare Diseases and Congenital Heart Diseases: A Call for Genetic Insight

February 28 is celebrated all over the world as Rare Disease Day to increase the awareness of rare diseases and to accelerate the diagnosis and treatment of these diseases.If a disease prevalence is less than 1 in 2000, it is considered rare in Europe.In the USA, a disease is considered rare if it is 1 in 20 000.Each rare disease may be "rare" on its own, but collectively there are approximately 300 million people in the world living with a rare disease.In Trkiye, 2.9 to 4.8 million people are living with at least one rare disease, but this number is probably higher due to many undiagnosed cases.Seventy percent of these rare diseases are diagnosed in children.