INTRODUCTION: Around 50% of Noonan syndrome (NS) patients present heterozygous mutations in the PTPN11 gene. AIM: To evaluate the frequency of mutations in the PTPN11 in patients with NS, and perform phenotype-genotype correlation. PATIENTS: 33 NS patients (23 males). METHODS: DNA was extracted from peripheral blood leukocytes, and all 15 PTPN11 exons were directly sequenced. RESULTS: Nine different missense mutations, including the novel P491H, were found in 16 of 33 NS patients. The most frequently observed features in NS patients […]

We analyzed the clinical and molecular data of 205 patients with the three different clinical forms of 21-hydroxylase deficiency, in whom the clinical and molecular diagnosis were already defined. The most frequent mutations were I2 splice in the salt wasting form, I172N in the simple virilizing and V281L in the nonclassical form, presenting similar frequencies as those observed in other populations. We found a lower frequency of 21-hydroxylase gene deletion, similar to that previously identified in Argentinean and Mexican populations. […]