Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033377 (prolapse)
 11,717 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

RASopathies are autosomal dominant disorders caused by mutations in more than 10 known genes that regulate the RAS/MAPK pathway. Noonan syndrome (NS) is a RASopathy characterized by a distinctive facial appearance, musculoskeletal abnormalities, and congenital heart defects. We have recently identified mutations in RIT1 in patients with NS. To delineate the clinical manifestations in RIT1 mutation-positive patients, we further performed a RIT1 analysis in RASopathy patients and identified 7 RIT1 mutations, including two novel mutations, p.A77S and p.A77T, in 14 of 186 patients. Perinatal abnormalities, including nuchal translucency, fetal hydrops, pleural effusion, or chylothorax and congenital heart defects, are observed in all RIT1 mutation-positive patients. Luciferase assays in NIH 3T3 cells demonstrated that the newly identified RIT1 mutants, including p.A77S and p.A77T, and the previously identified p.F82V, p.T83P, p.Y89H, and p.M90I, enhanced Elk1 transactivation. Genotype-phenotype correlation analyses of previously reported NS patients harboring RIT1, PTPN11, SOS1, RAF1, and KRAS revealed that hypertrophic cardiomyopathy (56 %) was more frequent in patients harboring a RIT1 mutation than in patients harboring PTPN11 (9 %) and SOS1 mutations (10 %). The rates of hypertrophic cardiomyopathy were similar between patients harboring RIT1 mutations and patients harboring RAF1 mutations (75 %). Short stature (52 %) was less prevalent in patients harboring RIT1 mutations than in patients harboring PTPN11 (71 %) and RAF1 (83 %) mutations. These results delineate the clinical manifestations of RIT1 mutation-positive NS patients: high frequencies of hypertrophic cardiomyopathy, atrial septal defects, and pulmonary stenosis; and lower frequencies of ptosis and short stature.
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PMID:Spectrum of mutations and genotype-phenotype analysis in Noonan syndrome patients with RIT1 mutations. 2671 97

Cardiofaciocutaneous (CFC) syndrome is one of the developmental disorders caused by a dysregulation of the Ras/mitogen-activated protein kinase (MAPK) pathway. RASopathies share overlapping clinical features, making the diagnosis challenging, especially in the newborn period. The majority of CFC syndrome cases arise by a mutation in the BRAF, MAP2K1, MAP2K2, or (rarely) KRAS genes. Germline KRAS mutations are identified in a minority of CFC and Noonan syndrome cases. Here, we describe a patient with a KRAS mutation presenting with a CFC syndrome phenotype. The female patient was referred for genetic testing because of congenital exophthalmos. Her facial appearance is distinctive with a coarse face, exophthalmos, ptosis, downslanting palpebral fissures, hypertelorism, deep philtrum, downturned corners of the mouth, and a short neck. She suffered from feeding difficulties, poor weight gain, and developmental delay. The sequencing of the genes involved in the MAPK pathway (PTPN11, SOS1, RAF1, KRAS, NRAS, MAP2K1, SHOC2, CBL, and SPRED1) identified a heterozygous de novo NM_004985.4:c.173C>T (p.Thr58Ile) in the KRAS gene. Germline KRAS mutations have been identified in approximately 2% of the reported NS cases and less than 5% of the reported CFC syndrome cases. Because CFC and Noonan syndrome share clinical overlapping features, the phenotype caused by KRAS mutations is often difficult to assign to one of the 2 entities. The mutation that we detected in our patient was previously reported in a patient with an Noonan syndrome phenotype. However, our patient predominantly exhibits CFC clinical features. In our case, coarse facial appearance and severe developmental delay help discriminate CFC from Noonan syndrome. Thus, patient follow-up, especially for delayed motor milestones suspected from RASopathies, is important for the discrimination of overlapping conditions as in the abovementioned syndromes.
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PMID:Cardiofaciocutaneous Syndrome Phenotype in a Case with de novo KRAS Pathogenic Variant. 3202 10