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)

The TWIST gene maps to 7p21 and mutations in the gene have been reported in the Saethre-Chotzen form of craniosynostosis. The position of the Saethre-Chotzen gene has previously been refined by FISH analysis of four patients carrying balanced translocations involving 7p21 which suggested that it was located between D7S488 and D7S503. We report here that the breakpoints in four translocation patients do not interrupt the coding sequence of the TWIST gene and thus most likely act through a positional effect. Twelve Saethre-Chotzen cases were found to have TWIST mutations. Four of these families had been used as part of the linkage study of the Saethre-Chotzen locus. The mutations detected included missense and nonsense mutations and three cases of a 21 bp duplication. Although phenotypically diagnosed as having Saethre-Chotzen syndrome, three families were found to have a pro250arg mutation of FGFR3.
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PMID:The TWIST gene, although not disrupted in Saethre-Chotzen patients with apparently balanced translocations of 7p21, is mutated in familial and sporadic cases. 925 86

Enlargement of the skull vault occurs by appositional growth at the fibrous joints between the bones, termed cranial sutures. Relatively little is known about the developmental biology of this process, but genetically determined disorders of premature cranial suture fusion (craniosynostosis) provide one route to the identification of some of the key molecules involved. Mutations of the MSX2, FGFR1, FGFR2, FGFR3 and TWIST genes yield new insights, both into normal and abnormal cranial suture biogenesis and into problems of broad interest, such as the conservation of molecular pathways in development, and mechanisms of mutation and dominance.
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PMID:Craniosynostosis: genes and mechanisms. 930 Jun 56

This article reviews recent molecular genetic findings in autosomal dominant craniosynostotic syndromes. A mutation in the homeotic gene MSX2 was the first genetic defect identified in an autosomal dominant primary craniosynostosis, i.e. in craniosynostosis type 2 (Boston type). In the more common syndromes of Crouzon, Pfeiffer, Jackson-Weiss, and Apert, mutations were found in the gene coding for fibroblast growth factor receptor (FGFR) 2. Less frequently, mutations are observed in FGFR1 and FGFR3 in some cases of Crouzon and Pfeiffer syndrome. The mutations identified in FGFR2 are located in exons 5 and 7 of the gene that code for immunoglobulin (Ig)-like chain III and the region linking Ig II and Ig III of the receptor. These domains of the receptor are important for ligand binding. Apart from Apert syndrome, identical mutations are found in the clinically distinct syndromes of Crouzon, Pfeiffer, and Jackson-Weiss. Furthermore, the same gene defect can result in a highly variable phenotype even within one family. Therefore, the clinically distinct craniosynostotic syndromes are extremes of a spectrum of craniofacial abnormalities and not nosologic entities. In Saethre-Chotzen syndrome, the gene coding for transcription factor TWIST is mutated. The disease genes identified in craniosynostotic syndromes to date either regulate transcription or are required for signal transduction and play a central role in the development of the calvarial sutures.
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PMID:Molecular genetics of craniosynostotic syndromes. 934 2

Thirty-two unrelated patients with features of Saethre-Chotzen syndrome, a common autosomal dominant condition of craniosynostosis and limb anomalies, were screened for mutations in TWIST, FGFR2, and FGFR3. Nine novel and three recurrent TWIST mutations were found in 12 families. Seven families were found to have the FGFR3 P250R mutation, and one individual was found to have an FGFR2 VV269-270 deletion. To date, our detection rate for TWIST or FGFR mutations is 68% in our Saethre-Chotzen syndrome patients, including our five patients elsewhere reported with TWIST mutations. More than 35 different TWIST mutations are now known in the literature. The most common phenotypic features, present in more than a third of our patients with TWIST mutations, are coronal synostosis, brachycephaly, low frontal hairline, facial asymmetry, ptosis, hypertelorism, broad great toes, and clinodactyly. Significant intra- and interfamilial phenotypic variability is present for either TWIST mutations or FGFR mutations. The overlap in clinical features and the presence, in the same genes, of mutations for more than one craniosynostotic condition-such as Saethre-Chotzen, Crouzon, and Pfeiffer syndromes-support the hypothesis that TWIST and FGFRs are components of the same molecular pathway involved in the modulation of craniofacial and limb development in humans.
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PMID:Genetic heterogeneity of Saethre-Chotzen syndrome, due to TWIST and FGFR mutations. 958 83

Sutural growth depends on maintenance of a balance between proliferation of osteogenic stem cells and their differentiation to form new bone, so that the stem cell population is maintained until growth of the skull is complete. The identification of heterozygous mutations in FGFR1, -2 and -3 and TWIST as well as microdeletions of TWIST in human craniosynostosis syndromes has highlighted these genes as playing important roles in maintaining the suture as a growth centre. In contrast to Drosophila, a molecular relationship between human (or other vertebrate) TWIST and FGFR genes has not yet been established. TWIST mutations exert their effect via haploinsufficiency whereas FGFR mutations have a gain-of-function mechanism of action. To investigate the biological basis of FGFR signalling pathways in the developing calvarium we compared the expression patterns of Twist with those of Fgfr1, -2 and -3 in the fetal mouse coronal suture over the course of embryonic days 14-18, as the suture is initiated and matures. Our results show that: (1) Twist expression precedes that of Fgfr genes at the time of initiation of the coronal suture; (2) in contrast to Fgfr transcripts, which are localised within and around the developing bone domains, Twist is expressed by the midsutural mesenchyme cells. Twist expression domains show some overlap with those of Fgfr2, which is expressed in the most immature (proliferating) osteogenic tissue.
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PMID:Expression patterns of Twist and Fgfr1, -2 and -3 in the developing mouse coronal suture suggest a key role for twist in suture initiation and biogenesis. 1070 61

Mutations in the FGFR1-FGFR3 and TWIST genes are known to cause craniosynostosis, the former by constitutive activation and the latter by haploinsufficiency. Although clinically achieving the same end result, the premature fusion of the calvarial bones, it is not known whether these genes lie in the same or independent pathways during calvarial bone development and later in suture closure. We have previously shown that Fgfr2c is expressed at the osteogenic fronts of the developing calvarial bones and that, when FGF is applied via beads to the osteogenic fronts, suture closure is accelerated (Kim, H.-J., Rice, D. P. C., Kettunen, P. J. and Thesleff, I. (1998) Development 125, 1241-1251). In order to investigate further the role of FGF signalling during mouse calvarial bone and suture development, we have performed detailed expression analysis of the splicing variants of Fgfr1-Fgfr3 and Fgfr4, as well as their potential ligand Fgf2. The IIIc splice variants of Fgfr1-Fgfr3 as well as the IIIb variant of Fgfr2 being expressed by differentiating osteoblasts at the osteogenic fronts (E15). In comparison to Fgf9, Fgf2 showed a more restricted expression pattern being primarily expressed in the sutural mesenchyme between the osteogenic fronts. We also carried out a detailed expression analysis of the helix-loop-helix factors (HLH) Twist and Id1 during calvaria and suture development (E10-P6). Twist and Id1 were expressed by early preosteoblasts, in patterns that overlapped those of the FGF ligands, but as these cells differentiated their expression dramatically decreased. Signalling pathways were further studied in vitro, in E15 mouse calvarial explants. Beads soaked in FGF2 induced Twist and inhibited Bsp, a marker of functioning osteoblasts. Meanwhile, BMP2 upregulated Id1. Id1 is a dominant negative HLH thought to inhibit basic HLH such as Twist. In Drosophila, the FGF receptor FR1 is known to be downstream of Twist. We demonstrated that in Twist(+/)(-) mice, FGFR2 protein expression was altered. We propose a model of osteoblast differentiation integrating Twist and FGF in the same pathway, in which FGF acts both at early and late stages. Disruption of this pathway may lead to craniosynostosis.
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PMID:Integration of FGF and TWIST in calvarial bone and suture development. 1075 Nov 73

Mutations in the fibroblast growth factor receptor 1, 2 and 3 (FGFR1, -2 and -3) and TWIST genes have been identified in several syndromic forms of craniosynostosis. There remains, however, a significant number of patients with non-syndromic craniosynostosis in whom no genetic cause can be identified. We describe a novel heterozygous mutation of FGFR2 (943G --> T, encoding the amino acid substitution Ala315Ser) in a girl with non-syndromic unicoronal craniosynostosis. The mutation is also present in her mother and her maternal grandfather who have mild facial asymmetry but do not have craniosynostosis. None of these individuals has the Crouzonoid appearance typically associated with FGFR2 mutations. However, the obstetric history revealed that the proband was in persistent breech presentation in utero and was delivered by Caesarean section, at which time compression of the skull was apparent. We propose that this particular FGFR2 mutation only confers a predisposition to craniosynostosis and that an additional environmental insult (in this case foetal head constraint associated with breech position) is necessary for craniosynostosis to occur. To our knowledge, this is the first report of an interaction between a weakly pathogenic mutation and intrauterine constraint, leading to craniosynostosis.
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PMID:A novel mutation, Ala315Ser, in FGFR2: a gene-environment interaction leading to craniosynostosis? 1095 18

We describe a consanguineous family of Pakistani origin with five sibs, three of whom were affected by craniosynostosis of variable presentation. In addition, they had other congenital abnormalities principally affecting neurological, ocular, and limb development. We provide linkage evidence using intragenic and flanking microsatellite markers suggesting that the disease in this family was not caused by a mutation in one of the known craniosynostosis loci (FGFR1, FGFR2, FGFR3, MSX2, TWIST). Given the clinical novelty and parental consanguinity, we hypothesise that the affected individuals were autozygous for a recessively inherited mutation, at a novel locus, predisposing to craniosynostosis.
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PMID:Newly recognised craniosynostosis syndrome that does not map to known disease loci. 1107 86

A cohort of 36 unrelated German patients with craniosynostosis syndromes of the Crouzon and Pfeiffer type were analyzed for FGFR mutations. Mutations in FGFR2 were identified in 25 Crouzon and 5 Pfeiffer syndrome patients, whereas no sequence alterations were found in the remaining patients, even after screening of the relevant parts of FGFR1, FGFR3, and TWIST. Mutations in FGFR2 clustered at two critical cysteine residues, 278 and 342, which were involved in 18 of 30 cases (60%). These two mutational hot spots, therefore, are prime targets for an efficient mutation-screening strategy. The spectrum of mutations overlapped the two syndromes and thus reflected the phenotypic similarities observed in both patient groups. In 21 families, the origin of the mutation could be traced by analyzing parents and relatives. Eleven mutations arose de novo, indicating a high mutation rate for FGFR2. In the 10 familial cases, the clinical presentation varied considerably within the pedigree, but both syndromes "bred true," i.e., a Pfeiffer syndrome phenotype was never observed in a Crouzon syndrome family and vice versa.
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PMID:Clustering of FGFR2 gene mutations inpatients with Pfeiffer and Crouzon syndromes (FGFR2-associated craniosynostoses). 1117 45

Non-syndromic trigonocephaly is a heterogeneous entity; in most cases the origin is unknown. Rare cases with autosomal dominant and recessive inheritance exist. Here the mutational screening of ten patients in the FGFR1, 2, and 3 genes and the TWIST gene causative of autosomal dominant craniosynostosis syndromes was reported. In one girl an unusual FGFR1 mutation was found.
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PMID:An unusual FGFR1 mutation (fibroblast growth factor receptor 1 mutation) in a girl with non-syndromic trigonocephaly. 1117 46


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