PTPN11 Mutations in LEOPARD Syndrome: Report of Four Cases in Taiwan

Background/PurposeLEOPARD syndrome (LS) is a rare, autosomal dominant disorder. The typical clinical presentation includes multiple lentigines and cardiac defects. Mutation analysis of the PTPN11 gene is feasible. We report four cases of LS, which were confirmed by molecular genetic study.MethodsThe clinical features and mutations of the four patients were summarized.ResultsThe diagnosis of all four patients was made when lentigines appeared during childhood. Three cases had hypertrophic cardiomyopathy. No electrocardiographic conduction abnormality was noted in any of the cases. Three patients had hypertelorism and three had short stature. Two patients, identical twins, presented with the atypical phenotype of tongue protrusion and hepatosplenomegaly at birth. Twin B had mild mental retardation. Case 4 had moderate hearing impairment. Point mutation of the PTPN11 gene was found in all patients.ConclusionLS has typical skin manifestations. All patients should undergo a comprehensive examination, especially echocardiography and electrocardiography. The diagnosis can be confirmed by genetic study.