The RAS/MAPK pathway proteins with germline mutations in their respective genes are associated with some disorders such as Noonan, LEOPARD (LS), neurofibromatosis type 1, Costello and cardio-facio-cutaneous syndromes. LEOPARD is an acronym, mnemonic for the major manifestations of this disorder, characterized by multiple lentigines, electrocardiographic abnormalities, ocular hypertelorism, pulmonic stenosis, abnormal genitalia, retardation of growth, and sensorineural deafness. Though it is not included in the acronym, hypertrophic cardiomyopathy is the most frequent cardiac anomaly observed, representing a potentially life-threatening problem in these patients. PTPN11, RAF1 and BRAF are the genes known to be associated with LS, identifying molecular genetic testing of the 3 gene mutations in about 95% of affected individuals. PTPN11 mutations are the most frequently found. Eleven different missense PTPN11 mutations (Tyr279Cys/Ser, Ala461Thr, Gly464Ala, Thr468Met/Pro, Arg498Trp/Leu, Gln506Pro, and Gln510Glu/Pro) have been reported so far in LS, 2 of which (Tyr279Cys and Thr468Met) occur in about 65% of the cases. Here, we provide an overview of clinical aspects of this disorder, the molecular mechanisms underlying pathogenesis and major genotype-phenotype correlations.
Hyperuricemia is defined as serum uric acid level of more than 7 mg/dL and blood levels of uric acid are causally associated with gout, as implicated by evidence from randomized clinical trials using urate lowering therapies. Uric acid as a cardiovascular risk factor often accompanies metabolic syndrome, hypertension, diabetes, dyslipidemia, chronic renal disease, and obesity. Despite the association of hyperuricemia with cardiovascular risk factors, it has remained controversial as to whether uric acid is an independent predictor of cardiovascular disease. To settle this issue, and in the absence of large randomized controlled trials, Mendelian randomization analysis in which the exposure is defined based on the presence or absence of a specific allele that influences a risk factor of interest have tried to shed light on this.
An eustachian valve (EV) remnant, if present, is usually noted by the presence of a thin ridge or a crescent-shaped fold of endocardium arising from the anterior rim of the inferior vena cava orifice due to the persistence of the right sinus venosus valve. Though the embryologic explanation of cor triatriatum dexter (CTD) is the same as that of the normal formation of the EV--lack of regression of the right sinus venosus valve--it is usually called CTD or divided right atrium when there are attachments on the atrial septum giving the appearance of a divided atrium. However, it's called prominent eustachian valve when the right sinus venosus valve has partly regressed, with no remaining septal attachments and without the appearance of a divided atrium. We present the case of an adult patient with an atrial septal defect with a high insertion of a giant EV, which mimics the echocardiographic appearance of divided right atrium.
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