@article {446, title = {WNT Signaling Perturbations Underlie the Genetic Heterogeneity of Robinow Syndrome.}, journal = {Am J Hum Genet}, volume = {102}, year = {2018}, month = {2018 01 04}, pages = {27-43}, abstract = {

Locus heterogeneity characterizes a variety of skeletal dysplasias often due to interacting or overlapping signaling pathways. Robinow syndrome is a skeletal disorder historically refractory to molecular diagnosis, potentially stemming from substantial genetic heterogeneity. All current known pathogenic variants reside in genes within the noncanonical Wnt signaling pathway including ROR2, WNT5A, and more recently, DVL1 and DVL3. However, \~{}70\% of autosomal-dominant Robinow syndrome cases remain molecularly unsolved. To investigate this missing heritability, we recruited 21 families with at least one family member clinically diagnosed with Robinow or Robinow-like phenotypes and performed genetic and genomic studies. In total, four families with variants in FZD2 were identified as well as three individuals from two families with biallelic variants in NXN that co-segregate with the phenotype. Importantly, both FZD2 and NXN are relevant protein partners in the WNT5A interactome, supporting their role in skeletal development. In addition to confirming that clustered -1 frameshifting variants in DVL1 and DVL3 are the main contributors to dominant Robinow syndrome, we also found likely pathogenic variants in candidate genes GPC4 and RAC3, both linked to the Wnt signaling pathway. These data support an initial hypothesis that Robinow syndrome results from perturbation of the Wnt/PCP pathway, suggest specific relevant domains of the proteins involved, and reveal key contributors in this signaling cascade during human embryonic development. Contrary to the view that non-allelic genetic heterogeneity hampers gene discovery, this study demonstrates the utility of rare disease genomic studies to parse gene function in human developmental pathways.

}, keywords = {Adolescent, Adult, Base Sequence, Child, Child, Preschool, Chromosome Segregation, Craniofacial Abnormalities, Diagnosis, Differential, Dwarfism, Female, Genes, Dominant, Genetic Association Studies, Genetic Heterogeneity, Humans, Limb Deformities, Congenital, Male, Middle Aged, Mutation, Missense, Phenotype, Urogenital Abnormalities, Wnt Signaling Pathway}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2017.10.002}, author = {White, Janson J and Mazzeu, Juliana F and Coban-Akdemir, Zeynep and Bayram, Yavuz and Bahrambeigi, Vahid and Hoischen, Alexander and van Bon, Bregje W M and Gezdirici, Alper and Gulec, Elif Yilmaz and Ramond, Francis and Touraine, Renaud and Thevenon, Julien and Shinawi, Marwan and Beaver, Erin and Heeley, Jennifer and Hoover-Fong, Julie and Durmaz, Ceren D and Karabulut, Halil Gurhan and Marzioglu-Ozdemir, Ebru and Cayir, Atilla and Duz, Mehmet B and Seven, Mehmet and Price, Susan and Ferreira, Barbara Merfort and Vianna-Morgante, Angela M and Ellard, Sian and Parrish, Andrew and Stals, Karen and Flores-Daboub, Josue and Jhangiani, Shalini N and Gibbs, Richard A and Brunner, Han G and Sutton, V Reid and Lupski, James R and Carvalho, Claudia M B} } @article {218, title = {Whole-exome sequencing identifies homozygous GPR161 mutation in a family with pituitary stalk interruption syndrome.}, journal = {J Clin Endocrinol Metab}, volume = {100}, year = {2015}, month = {2015 Jan}, pages = {E140-7}, abstract = {

CONTEXT: Pituitary stalk interruption syndrome (PSIS) is a rare, congenital anomaly of the pituitary gland characterized by pituitary gland insufficiency, thin or discontinuous pituitary stalk, anterior pituitary hypoplasia, and ectopic positioning of the posterior pituitary gland (neurohypophysis). The clinical presentation of patients with PSIS varies from isolated growth hormone (GH) deficiency to combined pituitary insufficiency and accompanying extrapituitary findings. Mutations in HESX1, LHX4, OTX2, SOX3, and PROKR2 have been associated with PSIS in less than 5\% of cases; thus, the underlying genetic etiology for the vast majority of cases remains to be determined.

OBJECTIVE: We applied whole-exome sequencing (WES) to a consanguineous family with two affected siblings who have pituitary gland insufficiency and radiographic findings of hypoplastic (thin) pituitary gland, empty sella, ectopic neurohypophysis, and interrupted pitiutary stalk-characteristic clinical diagnostic findings of PSIS.

DESIGN AND PARTICIPANTS: WES was applied to two affected and one unaffected siblings.

RESULTS: WES of two affected and one unaffected sibling revealed a unique homozygous missense mutation in GPR161, which encodes the orphan G protein-coupled receptor 161, a protein responsible for transducing extracellular signals across the plasma membrane into the cell.

CONCLUSION: Mutations of GPR161 may be implicated as a potential novel cause of PSIS.

}, keywords = {Adolescent, Child, Preschool, Exome, Female, Genome-Wide Association Study, Humans, Hypopituitarism, Mutation, Pituitary Gland, Receptors, G-Protein-Coupled}, issn = {1945-7197}, doi = {10.1210/jc.2014-1984}, author = {Karaca, Ender and Buyukkaya, Ramazan and Pehlivan, Davut and Charng, Wu-Lin and Yaykasli, Kursat O and Bayram, Yavuz and Gambin, Tomasz and Withers, Marjorie and Atik, Mehmed M and Arslanoglu, Ilknur and Bolu, Semih and Erdin, Serkan and Buyukkaya, Ayla and Yaykasli, Emine and Jhangiani, Shalini N and Muzny, Donna M and Gibbs, Richard A and Lupski, James R} } @article {233, title = {Whole exome sequencing identifies three novel mutations in ANTXR1 in families with GAPO syndrome.}, journal = {Am J Med Genet A}, volume = {164A}, year = {2014}, month = {2014 Sep}, pages = {2328-34}, abstract = {

GAPO syndrome (OMIM$\#$230740) is the acronym for growth retardation, alopecia, pseudoanodontia, and optic atrophy. About 35 cases have been reported, making it among one of the rarest recessive conditions. Distinctive craniofacial features including alopecia, rarefaction of eyebrows and eyelashes, frontal bossing, high forehead, mid-facial hypoplasia, hypertelorism, and thickened eyelids and lips make GAPO syndrome a clinically recognizable phenotype. While this genomic study was in progress mutations in ANTXR1 were reported to cause GAPO syndrome. In our study we performed whole exome sequencing (WES) for five affected individuals from three Turkish kindreds segregating the GAPO trait. Exome sequencing analysis identified three novel homozygous mutations including; one frame-shift (c.1220_1221insT; p.Ala408Cysfs*2), one splice site (c.411A>G; p.Gln137Gln), and one non-synonymous (c.1150G>A; p.Gly384Ser) mutation in the ANTXR1 gene. Our studies expand the allelic spectrum in this rare condition and potentially provide insight into the role of ANTXR1 in the regulation of the extracellular matrix.

}, keywords = {Adolescent, Adult, Alopecia, Anodontia, Base Sequence, Child, Chromosome Segregation, DNA Mutational Analysis, Exome, Facies, Family, Female, Growth Disorders, Humans, Male, Molecular Sequence Data, Mutation, Neoplasm Proteins, Optic Atrophies, Hereditary, Pedigree, Protein Structure, Tertiary, Receptors, Cell Surface}, issn = {1552-4833}, doi = {10.1002/ajmg.a.36678}, author = {Bayram, Yavuz and Pehlivan, Davut and Karaca, Ender and Gambin, Tomasz and Jhangiani, Shalini N and Erdin, Serkan and Gonzaga-Jauregui, Claudia and Wiszniewski, Wojciech and Muzny, Donna and Elcioglu, Nursel H and Yildirim, M Selman and Bozkurt, Banu and Zamani, Ayse Gul and Boerwinkle, Eric and Gibbs, Richard A and Lupski, James R} }