@article {38, title = {Cutaneous skeletal hypophosphatemia syndrome (CSHS) is a multilineage somatic mosaic RASopathy.}, journal = {J Am Acad Dermatol}, volume = {75}, year = {2016}, month = {2016 Aug}, pages = {420-7}, abstract = {

BACKGROUND: We recently demonstrated multilineage somatic mosaicism in cutaneous skeletal hypophosphatemia syndrome (CSHS), which features epidermal or melanocytic nevi, elevated fibroblast growth factor (FGF)-23, and hypophosphatemia, finding identical RAS mutations in affected skin and bone.

OBJECTIVE: We sought to: (1) provide an updated overview of CSHS; (2) review its pathobiology; (3)~present a new patient with CSHS; and (4) discuss treatment modalities.

METHODS: We searched PubMed for "nevus AND rickets," and "nevus AND hypophosphatemia," identifying cases of nevi with hypophosphatemic rickets or elevated serum FGF-23. For our additional patient with CSHS, we performed histopathologic and radiographic surveys of skin and skeletal lesions, respectively. Sequencing was performed for HRAS, KRAS, and NRAS to determine causative mutations.

RESULTS: Our new case harbored somatic activating HRAS p.G13~R mutation in affected tissue, consistent with previous findings. Although the mechanism of FGF-23 dysregulation is unknown in CSHS, interaction between FGF and MAPK pathways may provide insight into pathobiology. Anti-FGF-23 antibody KRN-23 may be useful in managing CSHS.

LIMITATIONS: Multilineage RAS mutation in CSHS was recently identified; further studies on mechanism are unavailable.

CONCLUSION: Patients with nevi in association with skeletal disease should be evaluated for serum phosphate and FGF-23. Further studies investigating the role of RAS in FGF-23 regulation are needed.

}, keywords = {Antibodies, Monoclonal, Antibodies, Monoclonal, Humanized, Fibroblast Growth Factor-23, Fibroblast Growth Factors, Genes, ras, Humans, Mosaicism, Nevus, Pigmented, Osteomalacia, Rickets, Hypophosphatemic, Skin Neoplasms, Syndrome}, issn = {1097-6787}, doi = {10.1016/j.jaad.2015.11.012}, author = {Lim, Young H and Ovejero, Diana and Derrick, Kristina M and Collins, Michael T and Choate, Keith A} } @article {189, title = {X-linked acrogigantism syndrome: clinical profile and therapeutic responses.}, journal = {Endocr Relat Cancer}, volume = {22}, year = {2015}, month = {2015 Jun}, pages = {353-67}, abstract = {

X-linked acrogigantism (X-LAG) is a new syndrome of pituitary gigantism, caused by microduplications on chromosome Xq26.3, encompassing the gene GPR101, which is highly upregulated in pituitary tumors. We conducted this study to explore the clinical, radiological, and hormonal phenotype and responses to therapy in patients with X-LAG syndrome. The study included 18 patients (13 sporadic) with X-LAG and microduplication of chromosome Xq26.3. All sporadic cases had unique duplications and the inheritance pattern in two families was dominant, with all Xq26.3 duplication carriers being affected. Patients began to grow rapidly as early as 2-3 months of age (median 12 months). At diagnosis (median delay 27 months), patients had a median height and weight standard deviation scores (SDS) of >+3.9 SDS. Apart from the increased overall body size, the children had acromegalic symptoms including acral enlargement and facial coarsening. More than a third of cases had increased appetite. Patients had marked hypersecretion of GH/IGF1 and usually prolactin, due to a pituitary macroadenoma or hyperplasia. Primary neurosurgical control was achieved with extensive anterior pituitary resection, but postoperative hypopituitarism was frequent. Control with somatostatin analogs was not readily achieved despite moderate to high levels of expression of somatostatin receptor subtype-2 in tumor tissue. Postoperative use of adjuvant pegvisomant resulted in control of IGF1 in all five cases where it was employed. X-LAG is a new infant-onset gigantism syndrome that has a severe clinical phenotype leading to challenging disease management.

}, keywords = {Acromegaly, Adenoma, Adolescent, Child, Child, Preschool, Chromosomes, Human, X, Female, Gigantism, Humans, Infant, Male, Pituitary Neoplasms, Young Adult}, issn = {1479-6821}, doi = {10.1530/ERC-15-0038}, author = {Beckers, Albert and Lodish, Maya Beth and Trivellin, Giampaolo and Rostomyan, Liliya and Lee, Misu and Faucz, Fabio R and Yuan, Bo and Choong, Catherine S and Caberg, Jean-Hubert and Verrua, Elisa and Naves, Luciana Ansaneli and Cheetham, Tim D and Young, Jacques and Lysy, Philippe A and Petrossians, Patrick and Cotterill, Andrew and Shah, Nalini Samir and Metzger, Daniel and Castermans, Emilie and Ambrosio, Maria Rosaria and Villa, Chiara and Strebkova, Natalia and Mazerkina, Nadia and Gaillard, St{\'e}phan and Barra, Gustavo Barcelos and Casulari, Luis Augusto and Neggers, Sebastian J and Salvatori, Roberto and Jaffrain-Rea, Marie-Lise and Zacharin, Margaret and Santamaria, Beatriz Lecumberri and Zacharieva, Sabina and Lim, Ee Mun and Mantovani, Giovanna and Zatelli, Maria Chaira and Collins, Michael T and Bonneville, Jean-Fran{\c c}ois and Quezado, Martha and Chittiboina, Prashant and Oldfield, Edward H and Bours, Vincent and Liu, Pengfei and W de Herder, Wouter and Pellegata, Natalia and Lupski, James R and Daly, Adrian F and Stratakis, Constantine A} } @article {289, title = {Multilineage somatic activating mutations in HRAS and NRAS cause mosaic cutaneous and skeletal lesions, elevated FGF23 and hypophosphatemia.}, journal = {Hum Mol Genet}, volume = {23}, year = {2014}, month = {2014 Jan 15}, pages = {397-407}, abstract = {

Pathologically elevated serum levels of fibroblast growth factor-23 (FGF23), a bone-derived hormone that regulates phosphorus homeostasis, result in renal phosphate wasting and lead to rickets or osteomalacia. Rarely, elevated serum FGF23 levels are found in association with mosaic cutaneous disorders that affect large proportions of the skin and appear in patterns corresponding to the migration of ectodermal progenitors. The cause and source of elevated serum FGF23 is unknown. In those conditions, such as epidermal and large congenital melanocytic nevi, skin lesions are variably associated with other abnormalities in the eye, brain and vasculature. The wide distribution of involved tissues and the appearance of multiple segmental skin and bone lesions suggest that these conditions result from early embryonic somatic mutations. We report five such cases with elevated serum FGF23 and bone lesions, four with large epidermal nevi and one with a giant congenital melanocytic nevus. Exome sequencing of blood and affected skin tissue identified somatic activating mutations of HRAS or NRAS in each case without recurrent secondary mutation, and we further found that the same mutation is present in dysplastic bone. Our finding of somatic activating RAS mutation in bone, the endogenous source of FGF23, provides the first evidence that elevated serum FGF23 levels, hypophosphatemia and osteomalacia are associated with pathologic Ras activation and may provide insight in the heretofore limited understanding of the regulation of FGF23.

}, keywords = {Adolescent, Child, Exome, Female, Fibroblast Growth Factors, Gene Expression Regulation, Developmental, GTP Phosphohydrolases, Humans, Hypophosphatemia, Male, Membrane Proteins, Mutation, Nevus, Nevus, Pigmented, Osteomalacia, Proto-Oncogene Proteins p21(ras), Sequence Analysis, DNA, Skin, Skin Neoplasms}, issn = {1460-2083}, doi = {10.1093/hmg/ddt429}, author = {Lim, Young H and Ovejero, Diana and Sugarman, Jeffrey S and Deklotz, Cynthia M C and Maruri, Ann and Eichenfield, Lawrence F and Kelley, Patrick K and J{\"u}ppner, Harald and Gottschalk, Michael and Tifft, Cynthia J and Gafni, Rachel I and Boyce, Alison M and Cowen, Edward W and Bhattacharyya, Nisan and Guthrie, Lori C and Gahl, William A and Golas, Gretchen and Loring, Erin C and Overton, John D and Mane, Shrikant M and Lifton, Richard P and Levy, Moise L and Collins, Michael T and Choate, Keith A} }