A 2-year-old boy with clinical features consistent with achondroplasia and Silver-Russell syndrome-like symptoms was found to carry a mutation in the fibroblast growth factor receptor-3 (FGFR3) gene at c.1138G > A (p.Gly380Arg) and a de novo 574 kb duplication at chromosome 7p12.1 that involved the entire growth-factor receptor bound protein 10 (GRB10) gene.
Moreover, we show that low dose of NVP-BGJ398 improves in vivo condyle growth and corrects dysmorphologies in Fgfr3<sup>Y367C/+</sup> mice, suggesting that postnatal treatment with NVP-BGJ398 mice might offer a new therapeutic strategy to improve mandible anomalies in ACH and others FGFR3-related disorders.
NVP-BGJ398 inhibited FGFR3 downstream signaling pathways, including MAPK, SOX9, STAT1, and PLCγ, in the growth plates of Fgfr3Y367C/+ mice and in cultured chondrocyte models of ACH.
To determine whether the fetus carries the de novo mis-sense genetic mutation at nucleotide 1138 in FGFR3 gene involved in >99% of achondroplasia cases, we developed two independent methods: digital-droplet PCR combined with minisequencing, which are very sensitive methods allowing detection of rare alleles.
Gain-of-function mutations in the FGFR3 gene result in chondrodysplasias which include achondroplasia (ACH), the most common form of dwarfism, in which skull, appendicular and axial skeletons are affected.
Mutations in the fibroblast growth factor receptor 3 (FGFR3) gene account for six related skeletal dysplasia conditions: achondroplasia, hypochondroplasia, thanatophoric dysplasia types 1 and 2, SADDAN (severe achondroplasia with developmental delay and acanthosis nigricans), and platyspondylic lethal skeletal dysplasia, San Diego type.
When grouped according to the "International Skeletal Dysplasia Society 2010 classification" the most frequent group is "FGFR3 group" (achondroplasia).
Recently it has been demonstrated that FGFR3 mutations affect not only endochondral ossification but also membranous ossification, providing new explanations for the craniofacial hallmarks in achondroplasia.
A group of unrelated patients (n=82), characterized by short stature, dysmorphology and X-ray abnormalities, of which mucopolysacharidoses, GM1 gangliosidosis, mucolipidosis type II/III and achondroplasia owing to FGFR3G380R mutation had been excluded, were recruited in this study.
Most reported mutations in the FGFR3 gene are dominant activating mutations that cause a variety of short-limbed bone dysplasias including achondroplasia and syndromic craniosynostosis.
FGFR3 is a negative regulator of chondrogenesis and multiple mutations with constitutive activity of FGFR3 result in achondroplasia, one of the most common dwarfisms in humans, but the molecular mechanism remains elusive.
Meclozine also ameliorated abnormally suppressed proliferation of human chondrosarcoma (HCS-2/8) cells that were infected with lentivirus expressing constitutively active mutants of FGFR3-K650E causing thanatophoric dysplasia, FGFR3-K650M causing SADDAN, and FGFR3-G380R causing ACH.
The classic example of a genetic disorder exhibiting a PAE is achondroplasia, caused predominantly by a single-nucleotide substitution (c.1138G>A) in FGFR3.
Instead, the phosphorylation efficiency within un-liganded FGFR3 dimers is increased, and this increase is likely the underlying cause for pathogenesis in achondroplasia.
Compared with RFLP-PCR, HRM analysis provided a more rapid, simpler, and less expensive approach for detecting the most common FGFR3 mutations carried by patients with ACH.
A regulation that occurs mainly in the mesomelic segments, a region where SHOX is known to be strongly expressed, offers a possible explanation for the phenotypes seen in patients with FGFR3 (e.g. achondroplasia) and SHOX defects (e.g.Léri-Weill dyschondrosteosis).
In 1994, the field of bone biology was significantly advanced by the discovery that activating mutations in the fibroblast growth factor receptor 3 (FGFR3) receptor tyrosine kinase (TK) account for the common genetic form of dwarfism in humans, achondroplasia (ACH).
The data are consistent with the idea that the ACH mutation causes a structural change which affects both the stability and the activity of FGFR3 dimers in the absence of ligand.
Gain-of-function mutations in fibroblast growth factor receptor-3 (FGFR3) lead to several types of human skeletal dysplasia syndromes including achondroplasia, hypochondroplasia and thanatophoric dysplasia (TD).