title: LEOPARD syndrome (PTPN11, T468M) in three boys fulfilling neurofibromatosis type 1 clinical criteria.
abstract: Noonan syndrome (NS) and neurofibromatosis type 1 (NF1) are well-defined entities. The association of both disorders is called neurofibromatosis-Noonan syndrome (NFNS), a disorder that has been related to mutations in the NF1 gene. Both NS and NFNS display phenotypic overlapping with LEOPARD syndrome (LS), and differential diagnosis between these two entities often represents a challenge for clinicians. We report on three patients (two brothers and a not-related patient) diagnosed as having NFNS. They fulfilled NF1 diagnostic criteria and had some features of NS. The three of them had hypertophic cardiomyopathy while neurofibromas, Lisch nodules, and unidentified bright objects on MRI were absent. PTPN11 gene assays revealed a T468M mutation, typical of LS. Thorough clinical examinations of the patients revealed multiple lentigines, which were considered to be freckling in the initial evaluation. We conclude that NF1 clinical criteria should be used with caution in patients with features of NS. Patients with hyperpigmented cutaneous spots associated with cardiac anomalies, even if fulfilling the minimal NF1 criteria for diagnosis, should be strongly considered for LS diagnosis.
authors.affiliation: Pediatrics Department, Hospital Virgen de la Salud, Toledo, Spain. atcarcavilla@gmail.com
authors.forename: Atilano
authors.initials: A
authors.lastname: Carcavilla
authors.forename: Isabel
authors.initials: I
authors.lastname: Pinto
authors.forename: Rafael
authors.initials: R
authors.lastname: Muñoz-Pacheco
authors.forename: Raquel
authors.initials: R
authors.lastname: Barrio
authors.forename: Maria
authors.initials: M
authors.lastname: Martin-Frías
authors.forename: Begoña
authors.initials: B
authors.lastname: Ezquieta
mesh_terms: D000293:Adolescent; D002648:Child; D004252:DNA Mutational Analysis; D003937:Diagnosis, Differential; D006801:Humans; D007223:Infant; D044542:LEOPARD Syndrome / Q000175:diagnosis* / Q000235:genetics; D008297:Male; D009456:Neurofibromatosis 1 / Q000175:diagnosis*; D009634:Noonan Syndrome / Q000175:diagnosis*; D010375:Pedigree; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11 / Q000235:genetics
chemical_list: C516724:PTPN11 protein, human; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11