It is estimated that between 3 and 6% of newborns worldwide suffer from some type of inherited condition, although not all are serious. Some of these genetic disorders are detected during pregnancy, others at birth, while others may go unnoticed until children grow up or even develop into adulthood.
The most common causes for referring pediatric patients to a genetic unit based on their incidence are: inborn errors of metabolism (1 in 800 births), Down syndrome (1 in 700 births), Fragile X syndrome (1 in 5,000 births) and lysosomal storage disorders (1 in 7,000).
However, there is an increasing number of diseases whose frequency is much lower (less than 5 out of every 10,000 births) and are called rare or minority diseases and due to the scarcity of cases studied, diagnosis without genetic analysis becomes a long and complicated process.