@article {408, title = {Hypogonadotropic Hypogonadism due to Novel FGFR1 Mutations.}, journal = {J Clin Res Pediatr Endocrinol}, volume = {9}, year = {2017}, month = {2017 Jun 01}, pages = {95-100}, abstract = {

OBJECTIVE: The underlying genetic etiology of hypogonadotropic hypogonadism (HH) is heterogeneous. Fibroblast growth factor signaling is pivotal in the ontogeny of gonadotropin-releasing hormone neurons. Loss-of-function mutations in FGFR1 gene cause variable HH phenotypes encompassing pubertal delay to idiopathic HH (IHH) or Kallmann syndrome (KS). As FGFR1 mutations are common, recognizing mutations and associated phenotypes may enhance clinical management.

METHODS: Using a candidate gene approach, we screened 52 IHH/KS patients.

RESULTS: We identified three novel (IVS3-1G>C and p.W2X, p.R209C) FGFR1 gene mutations. Despite predictive null protein function, patients from the novel mutation families had normosmic IHH without non-reproductive phenotype.

CONCLUSION: These findings further emphasize the great variability of FGFR1 mutation phenotypes in IHH/KS.

}, keywords = {Adolescent, Adult, Family Health, Female, Genetic Predisposition to Disease, Genotype, Humans, Hypogonadism, Klinefelter Syndrome, Male, Mutation, Pedigree, Phenotype, Puberty, Delayed, Receptor, Fibroblast Growth Factor, Type 1, Young Adult}, issn = {1308-5735}, doi = {10.4274/jcrpe.3908}, author = {Akku{\c s}, Gamze and Kotan, Leman Damla and Durmaz, Erdem and Mengen, Eda and Turan, {\.I}hsan and Ulubay, Ay{\c c}a and G{\"u}rb{\"u}z, Fatih and Y{\"u}ksel, Bilgin and Tetiker, Tamer and Topalo{\u g}lu, A Kemal} } @article {74, title = {Mosaic Activating Mutations in FGFR1 Cause Encephalocraniocutaneous Lipomatosis.}, journal = {Am J Hum Genet}, volume = {98}, year = {2016}, month = {2016 Mar 03}, pages = {579-587}, abstract = {

Encephalocraniocutaneous lipomatosis (ECCL) is a sporadic condition characterized by ocular, cutaneous, and central nervous system anomalies. Key clinical features include a well-demarcated hairless fatty nevus on the scalp, benign ocular tumors, and central nervous system lipomas. Seizures, spasticity, and intellectual disability can be present, although affected individuals without seizures and with normal intellect have also been reported. Given the patchy and asymmetric nature of the malformations, ECCL has been hypothesized to be due to a post-zygotic, mosaic mutation. Despite phenotypic overlap with several other disorders associated with mutations in the RAS-MAPK and PI3K-AKT pathways, the molecular etiology of ECCL remains unknown. Using exome sequencing of DNA from multiple affected tissues from five unrelated individuals with ECCL, we identified two mosaic mutations, c.1638C>A (p.Asn546Lys) and c.1966A>G (p.Lys656Glu) within the tyrosine kinase domain of FGFR1, in two affected individuals each. These two residues are the most commonly mutated residues in FGFR1 in human cancers and are associated primarily with CNS tumors. Targeted resequencing of FGFR1 in multiple tissues from an independent cohort of individuals with ECCL identified one additional individual with a c.1638C>A (p.Asn546Lys) mutation in FGFR1. Functional studies of ECCL fibroblast cell lines show increased levels of phosphorylated FGFRs and phosphorylated FRS2, a direct substrate of FGFR1, as well as constitutive activation of RAS-MAPK signaling. In addition to identifying the molecular etiology of ECCL, our results support the emerging overlap between mosaic developmental disorders and tumorigenesis.

}, keywords = {Adolescent, Cell Line, Tumor, Central Nervous System Neoplasms, Child, Preschool, Exome, Eye, Eye Diseases, Female, Humans, Infant, Lipomatosis, Male, Mutation, Mutation, Missense, Neurocutaneous Syndromes, Phosphatidylinositol 3-Kinases, Proto-Oncogene Proteins c-akt, Receptor, Fibroblast Growth Factor, Type 1, Seizures, Sequence Analysis, DNA}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.02.006}, author = {Bennett, James T and Tan, Tiong Yang and Alcantara, Diana and T{\'e}trault, Martine and Timms, Andrew E and Jensen, Dana and Collins, Sarah and Nowaczyk, Malgorzata J M and Lindhurst, Marjorie J and Christensen, Katherine M and Braddock, Stephen R and Brandling-Bennett, Heather and Hennekam, Raoul C M and Chung, Brian and Lehman, Anna and Su, John and Ng, SuYuen and Amor, David J and Majewski, Jacek and Biesecker, Les G and Boycott, Kym M and Dobyns, William B and O{\textquoteright}Driscoll, Mark and Moog, Ute and McDonell, Laura M} }