Cochlear implantation and clinical features in patients with Noonan syndrome and Noonan syndrome with multiple lentigines caused by a mutation in PTPN11.

Existing literature only reports a few patients with Noonan syndrome (NS) and Noonan syndrome with multiple lentigines (NSML) who underwent cochlear implantation (CI). The present study describes four NS patients and one NSML patient with a PTPN11 mutation. They all had severe to profound hearing loss, and they received a CI. The age at which the CI surgery occurred ranged from 1 to 13 years old, and the audiological results in all five patients improved after the CI. Otological and audiological examinations in NS and NSML are important, and for those with severe hearing loss, the CI surgery improved the audiological outcome regardless of age.

LEOPARD syndrome: you could be the first one to diagnose!

Leopard syndrome is a rare genetic disease complex associated with multiple anomalies. The main anomalies are summarized in the acronym LEOPARD in which each letter corresponds to mnemonic for the major features of this disorder:multiple Lentigines, ECG conduction abnormalities, Ocular hypertelorism, Pulmonic stenosis, Abnormal genitalia, Retardation of growth, and sensory neural Deafness. A Four year old male patient reported with the chief complaint of decayed anterior tooth without any relevant past medical history. Based on the clinical features; the child was subjected to genetic and general physical appraisal which helped in identifying Leopard syndrome. A multidisciplinary approach by the pedodontist and medical consultants aided in the identification and management of this rare syndrome. LEOPARD syndrome has been rarely reported in the diseases associated with oro-dental or craniofacial anomalies. In this case report we describe these anomalies and discuss the relationship between them and the proposed etiology of the disease.

Implantable cardioverter defibrillator for progressive hypertrophic cardiomyopathy in a patient with LEOPARD syndrome and a novel PTPN11 mutation Gln510His.

LEOPARD syndrome (LS), generally caused by heterozygous mutations in the PTPN11 gene, is a rare autosomal-dominant multiple congenital anomaly condition, characterized by skin, facial, and cardiac abnormalities. Prognosis appears to be related to the type of structural, myocardial, and arrhythmogenic cardiac disease, especially hypertrophic cardiomyopathy (HCM). We report on a woman with LS and a novel Gln510His mutation in PTPN11, who had progressive HCM with congestive heart failure and nonsustained ventricular tachycardia, successfully treated with implantable cardioverter defibrillator (ICD). Comparing our patient to the literature suggests that specific mutations at codon 510 in PTPN11 (Gln510Glu, Gln510His, but not Gln510Pro) might be a predictor of fatal cardiac events in LS. Molecular risk stratification and careful evaluations for an indication of ICD implantation are likely to be beneficial in managing patients with LS and HCM.

PTPN11-associated mutations in the heart: has LEOPARD changed Its RASpots?

In this review, we focus on elucidating the cardiac function of germline mutations in the PTPN11 gene, encoding the Src homology-2 (SH2) domain-containing protein tyrosine phosphatase SHP2. PTPN11 mutations cause LEOPARD syndrome (LS) and Noonan syndrome (NS), two disorders that are part of a newly classified family of autosomal dominant syndromes termed "RASopathies," which are caused by germline mutations in components of the RAS/RAF/MEK/ERK mitogen activating protein kinase pathway. LS and NS mutants have opposing biochemical properties, and yet, in patients, these mutations produce similar cardiac abnormalities. Precisely how LS and NS mutations lead to such similar disease etiology remains largely unknown. Recent complementary in vitro, ex vivo, and in vivo analyses reveal new insights into the functions of SHP2 in normal and pathological cardiac development. These findings also reveal the need for individualized therapeutic approaches in the treatment of patients with LS and NS and, more broadly, patients with the other "RASopathy" gene mutations as well.

PTPN11 mutations in LEOPARD syndrome: report of four cases in Taiwan.

BACKGROUND/PURPOSE: LEOPARD 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. METHODS: The clinical features and mutations of the four patients were summarized. RESULTS: The 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. CONCLUSION: LS has typical skin manifestations. All patients should undergo a comprehensive examination, especially echocardiography and electrocardiography. The diagnosis can be confirmed by genetic study.

Leopard syndrome.

LEOPARD syndrome (LS, OMIM 151100) is a rare multiple congenital anomalies condition, mainly characterized by skin, facial and cardiac anomalies. LEOPARD is an acronym for the major features of this disorder, including multiple Lentigines, ECG conduction abnormalities, Ocular hypertelorism, Pulmonic stenosis, Abnormal genitalia, Retardation of growth, and sensorineural Deafness. About 200 patients have been reported worldwide but the real incidence of LS has not been assessed. Facial dysmorphism includes ocular hypertelorism, palpebral ptosis and low-set ears. Stature is usually below the 25th centile. Cardiac defects, in particular hypertrophic cardiomyopathy mostly involving the left ventricle, and ECG anomalies are common. The lentigines may be congenital, although more frequently manifest by the age of 4-5 years and increase throughout puberty. Additional common features are café-au-lait spots (CLS), chest anomalies, cryptorchidism, delayed puberty, hypotonia, mild developmental delay, sensorineural deafness and learning difficulties. In about 85% of the cases, a heterozygous missense mutation is detected in exons 7, 12 or 13 of the PTPN11 gene. Recently, missense mutations in the RAF1 gene have been found in two out of six PTPN11-negative LS patients. Mutation analysis can be carried out on blood, chorionic villi and amniotic fluid samples. LS is largely overlapping Noonan syndrome and, during childhood, Neurofibromatosis type 1-Noonan syndrome. Diagnostic clues of LS are multiple lentigines and CLS, hypertrophic cardiomyopathy and deafness. Mutation-based differential diagnosis in patients with borderline clinical manifestations is warranted. LS is an autosomal dominant condition, with full penetrance and variable expressivity. If one parent is affected, a 50% recurrence risk is appropriate. LS should be suspected in foetuses with severe cardiac hypertrophy and prenatal DNA test may be performed. Clinical management should address growth and motor development and congenital anomalies, in particular cardiac defects that should be monitored annually. Hypertrophic cardiomyopathy needs careful risk assessment and prophylaxis against sudden death in patients at risk. Hearing should be evaluated annually until adulthood. With the only exception of ventricular hypertrophy, adults with LS do not require special medical care and long-term prognosis is favourable.