Endocrine Abstracts

Leopard syndrome (LS) is a rare autosomal dominant disease of variable penetrance and clinical expression. LEOPARD is an acronym for the major features of the disorder: lentigines, ECG conduction abnormalities, Ocular hypertelorism, pulmonary stenosis, abnormal genitalia, retardation of growth, and deafness. LS is caused by different mutations in PTPN11 gene (protein-tyrosine phosphatase, nonreceptor-type, 11), allelic with Noonan syndrome (NS). The diagnosis is established if multiple lentigines are present in association with at least two other cardinal features. To date, approximately 200 cases have been reported but the real frequency may be underestimated. We present the case of a male patient who was referred to the endocrinological department at the age of 18 for short stature (−3 S.D.) and delayed puberty (Tanner III). The association of multiple lentigines, echocardiographic abnormalities including large pulmonary stenosis, trivalvular insufficiency, and hypertelorism, suggested the diagnosis of LS, which was confirmed by a heterozygous substitution mutation detected in exon 13 of the PTPN11 gene. Other less frequent features, as triangular face, cafe-au-lait spots, and retractile testis were also present. He also presented right spastic hemiparesis and left central facial palsy, and brain IRM identified a large tumour located mainly in the cerebellum. Partial surgery was performed with improvement of the neurological symptoms. Pathology confirmed pilocytic astrocytoma. To our knowledge, this is the first report of a LS associated with astrocytoma. Tumours as neuroblastoma, choristoma and malignant melanoma have been described in few cases. Dysregulations of the RAS/MAPK (RAS/mitogen activated protein kinase) cascade seems to be the common molecular base for congenital syndromes as LS, NS, type 1 neurofibromatosis (which has an increased risk for astrocytoma). More than that, recent studies implicate aberrant activation of MAPK pathway as a molecular pathogenesis in astrocytoma. Therefore, we which suggest that LS-astrocytoma may be more than a random association.