Hotspots in PTPN11 gene among Indian children with Noonan syndrome

To test for PTPN11 mutations in clinically diagnosed cases of Noonan syndrome. 17 individuals with clinical diagnosis of Noonan syndrome were included in the study. Sanger sequencing of all the 15 exons of PTPN11 was done. A genotype-phenotype correlation was attempted. Mutation in PTPN11 was detected in 11 out of 17 (64.7 %) patients with Noonan syndrome; 72% had mutation in exon 3 and 27 % had mutation in exon 13. PTPN11 mutation accounts for 64.7% of cases with clinical features of Noonan syndrome in India. Majority of the mutations are in exon 3 and exon 13 of PTPN11, making them the hotspots in Indian population.