Clinically relevant examples of genotype-phenotype correlation

Although Fabry disease is a rare lysosomal storage disorder, intensive research has been performed in the last decade in order to elucidate the pathogenesis, underlying mechanisms and the best treatment for this disorder. Despite this, the motto '10 years 10 doctors' is still the reality mainly because of the difficulty to correlate between different signs and symptoms in one rare disease. Furthermore, there is no good correlation between phenotype-genotype and it is difficult if not impossible to predict which genotype will develop into a complete or partial Fabry phenotype and which females will remain asymptomatic and which will develop symptoms. This chapter will focus on describing the efforts that have been made over the years in order to try to correlate genotypes with specific phenotypes as well as modifier genes that might help predicting future symptoms of patients with Fabry disease.