Recent research has advanced the understanding of many diseases to a molecular level. Described here is the case of a teenage girl with proteinuria and primary amenorrhea. We present the current knowledge of her underlying disorder, Frasier syndrome, and its genetic basis, which are specific mutations in the Wilms tumor gene. The findings in Frasier syndrome research are contrasted with those of a related disorder, Denys-Drash syndrome, which is caused by different mutations in the same gene.