PTPN11 gene mutation in LEOPARD syndrome

The multiple lentigines/LEOPARD syndrome (ML/LS) is a rare and complex genetic syndrome. It is an autosomal dominant disorder with a variable expressivity. The syndrome is mainly characterised by growth retardation, multiple lentigines, and congenital heart diseases with electrocardiographic anomalies, dysmorphia of the face and deafness. The incidence of this pathology is still unknown and a familial inheritance is present in 70% of cases. Some of the ML/LS clinical features are the same as those of the Noonan syndrome (NS), such as congenital cardiac abnormalities, dysmorphia and growth retardation. NS and ML/LS are caused by allele mutations of the PTPN11 gene. We report the case of a 3-year-oldgir1, who was observed for the presence of widespread lentigines, a 1/6-proto-systolic murmur at the mesocardium and growth retardation. The diagnosis of ML/LS was made and thus a molecular analysis of the PTPN11 gene was carried out, directly sequencing the codifying region. The molecular analysis revealed a missense mutation (A836G) in hexone 7 (TYR279CYS) of the PT-PNII gene. This mutation is has been observed, at present, in a few cases of ML/LS and Noonan syndrome.