Hotspots in PTPN11 gene among Indian children with Noonan syndrome

Objectives: To test for PTPN11 mutations in clinically diagnosed cases of Noonan syndrome. Methods: 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. Results: 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. Conclusion: 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.