Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.10.1 (ERK)
 95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mutations in the fibroblast growth factor receptor (FGFR) gene family recently have been shown to underlie several hereditary disorders of bone development, with specific FGFR3 mutations causing achondroplasia (Ach) and thanatophoric dysplasia (TD). However, for none of these mutations has the defect in receptor function been demonstrated directly and, therefore, for none has the pathophysiological mechanism of the disease been defined. Using our established techniques for single-cell ratiometric real-time calcium image analysis, we defined the nature of the basic fibroblast growth factor (bFGF)-induced calcium signal in human diploid fibroblasts, and, in blinded studies, have analyzed the bFGF-induced signals from 18 independent fibroblast cell lines, including multiple lines from patients with known mutant alleles of FGFR3 and syndromes of Ach or TD. Control cells responded with transient increases in intracellular calcium, with many cells showing oscillatory calcium waves. Homozygous Ach cell lines failed to signal, whereas heterozygous Ach lines responded nearly normally. We observed heterogeneous signals in TD heterozygotes: the unresponsive lines all turned out to carry TD1 alleles, whereas all responsive lines had TD2 alleles. Since FGFR1, 2 and 3 receptors are known to be expressed in fibroblasts, our results suggest that specific mutant FGFR3 alleles can function in a dosage-dependent dominant-negative fashion to inactivate FGFR signaling.
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PMID:Mutations causing achondroplasia and thanatophoric dysplasia alter bFGF-induced calcium signals in human diploid fibroblasts. 915 42

We present a second family with survival to adulthood and dominant transmission of the Torrance-Luton type of platyspondylic chondrodysplasia, and demonstrate the radiographs at different ages together with radiographs and further data of the first family which was published in the Journal of Pediatrics (J Pediatr 136:411-413). Two families are described with survival to adulthood and dominant transmission of the Torrance-Luton type of platyspondylic chondrodysplasia. Although lethality is increased in patients with this disorder, mild expressions of the genetic defect are compatible with survival into adulthood. The heterogeneous group of platyspondylic lethal skeletal dysplasias (PLSD) originally included thanatophoric dysplasias (TD1/2: MIM 187600, 187100) as the most common forms of this condition, as well as TD variants San Diego type (PLSD-SD: MIM 270230) and Torrance-Luton type (PLSD-TL: MIM 151210). Fibroblast growth factor receptor 3 ( FGFR3) gene mutations have been detected in TD1/2 and PLSD-SD. Molecular studies in one of our two families with the Torrance-Luton type did not disclose mutations in the FGFR3 coding region, suggesting that this type of platyspondylic chondrodysplasia is not a thanatophoric dysplasia variant. In contrast to TD1/2 and PLD-SD, the Torrance-Luton type platyspondylic dysplasia is compatible with survival to adulthood.
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PMID:Survival to adulthood and dominant inheritance of platyspondylic skeletal dysplasia, Torrance-Luton type. 1296 Oct 49

The activating mutation FGFR3-R248C in the D2-D3 linker region of fibroblast growth factor receptor 3 leads as germline mutation to the neonatal lethal syndrome thanatophoric dysplasia type I (TD1). As somatic mutation it has been found in cancer. We introduced into the murine FGFR3 the mutation R242C that is orthologoues to the human mutation R248C. A strong reduction in binding of the 16 and 18 kDa forms of FGF1 to the mutant receptor was found, highlighting the importance of D2-D3 linker region of FGFR3 in determination of binding affinity to ligands. Another mutant, G374R, introduced into the murine FGFR3, is orthologoues to the human mutant FGFR3-G380R, and leads to achondroplasia (ACH). The binding of the 16 kDa and 18 kDa forms of FGF1 to this mutant receptor was the same as for wild-type FGFR3 in a cell-free system, but it was reduced in living cells. The data indicate a minor changes in conformation of FGFR3-G374R receptors at the cell surface that lead to reduced binding to FGF1.
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PMID:Reduced binding of FGF1 to mutant fibroblast growth factor receptor 3. 1680 Nov 31

Thanatophoric dysplasia (TD) is a lethal form of short-limb skeletal dysplasia that is associated with macrocephaly, and variably cloverleaf skull. Two types of TD are clinically recognized, TD1 and TD2, mainly distinguished by their radiographic characteristics. The differences between the two are principally observed in the femur, which appears curved in TD1, while it remains straight but with a proximal medial spike in TD2, and are a less severe overall affectation in TD2. Both types of TD are caused by mutations in different functional domains of the FGFR3 gene. However, whereas several mutations in the different domains of FGFR3 cause TD1, the K650E mutation involving the change of a lysine to glutamic acid ("Lys650Glu") has been found in all TD2 cases to date. Here we describe a newborn infant with TD2 associated with brain defects that have either been infrequently observed (encephalocele) or not hitherto described (holoprosencephaly). Based on recent studies, we consider encephaloceles described in TD to be pseudoencephaloceles, since they are secondary to the intracranial pressure generated by severe hydrocephaly and to severe cranial structural anomalies. Finally, to analyze the mechanisms of holoprosencephaly observed in the case described here, we include a concise review on the current understanding of how FGFs and their receptors are expressed in the rostral signaling center (particularly Fgf8). In addition, we evaluated recent observations that FGF ligands and receptors (including FGFR3) act in concert to organize the whole telencephalon activity, rather than independently patterning different areas.
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PMID:Thanatophoric dysplasia type II with encephalocele and semilobar holoprosencephaly: Insights into its pathogenesis. 2120 32

Thanatophoric dysplasia is a lethal form of chondrodysplastic dwarfism in which the cerebral cortex displays a unique and complex malformation. We report a female case of thanatophoric dysplasia type I (TD1) with FGFR3 mutation. In this case, fetal ultrasonography at the 18th week of gestation led to a prenatal diagnosis of TD1 with characteristic bone features. The subject was stillborn at the 21st week of gestation, showing marked shortening of the long bones, small thorax and curved short femurs, but without a cloverleaf skull. The temporal lobe was enlarged and hyperconvoluted, appearing as broad gyri and deep sulci, which were composed of focal polymicrogyria-like shallow sulci and heterotopic neuroblastic nests in the intermediate zone and marginal zone. Abundant precursor cells, immunoreactive for nestin and Ki-67 were observed with scattered mitoses in the thickened inner intermediate and subventricular zones of the temporal and occipital lobes. The cytoarchitecture from the entorhinal cortex to Ammon's horn was disorganized with leptomeningeal glioneuronal heterotopia, immunoreactive for doublecortin and nestin. The expression of FGFR3 was virtually not discernible in the temporal and occipital lobes or in the hippocampus. Genetic analysis revealed a point mutation at C8526T (R248C) in the exon 7 of FGFR3. This is the first report that demonstrates that overproduction of intermediate progenitor cells might be induced by FGFR3 mutation in a human TD1 case.
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PMID:Brain malformation with loss of normal FGFR3 expression in thanatophoric dysplasia type I. 2355 94