DNA sequencing has enabled the diagnosis of many rare diseases caused by genetic mutations that are inherited or arise spontaneously.
The sheer number of distinct conditions (over 10,000 genetically identified), with limited number of patients affected by each condition, and the highly variable clinical observations among individual patients, all make diagnosis and treatment highly challenging. The first clinical signs often appear in early childhood, with progressive loss of autonomy frequently associated with a short life expectancy. The low prevalence of rare diseases and the delay in achieving full diagnosis have until recently been hampering treatment.
Despite the often limited medical and scientific knowledge, natural history data, and drug development experience associated with an individual rare disease, individualized antisense oligonucleotide therapies administered through N-of-1 trials have been achieving meaningful clinical responses.
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