Phenotypic and molecular characterization of focal dermal hypoplasia in 18 individuals
AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS
Authors: Bostwick, Bret; Fang, Ping; Patel, Ankita; Sutton, V. Reid
Abstract
Focal dermal hypoplasia, or Goltz syndrome, is a highly variable X-linked dominant disorder with abnormalities in ectoderm and mesoderm derived tissues. Classic clinical features include patchy hypoplastic skin, split hand/foot deformities, and ocular malformations. We aimed to refine the understanding of the phenotypic spectrum and natural history of this disorder and now present multi-disciplinary clinical description and medical history review for 18 patients with focal dermal hypoplasia. All disease characteristics were analyzed and compiled in aggregate to aid in development of clinical diagnostic criteria. Medical history data unexpectedly revealed that the majority of patients (87%) had undergone tonsillectomy for obstructive sleep apnea, which exposed an important co-morbidity that is not well described in the literature, but managing physicians should be made aware of. Fifteen of the 18 patients underwent molecular sequencing of PORCN to detect heterozygous or mosaic mutations. Where no mutation was detected, we performed exon-targeted chromosomal microarray to evaluate for large deletions of the PORCN gene region. We detected a pathogenic genotype in 14 of 15 patients, including one novel chromosomal deletion and four novel PORCN sequence variants. Here, we provide phenotypic summary analysis of 18 patients with focal dermal hypoplasia and propose clinical diagnostic criteria. (c) 2016 Wiley Periodicals, Inc.
A uniform human Wnt expression library reveals a shared secretory pathway and unique signaling activities
DIFFERENTIATION
Authors: Najdi, Rani; Proffitt, Kyle; Sprowl, Stephanie; Kaur, Simran; Yu, Jia; Covey, Tracy M.; Virshup, David M.; Waterman, Marian L.
Abstract
Wnt ligands are secreted morphogens that control multiple developmental processes during embrygenesis and adult homeostasis. A diverse set of receptors and signals have been linked to individual Wnts, but the lack of tools for comparative analysis has limited the ability to determine which of these signals are general for the entire Wnt family, and which define subsets of differently acting ligands. We have created a versatile Gateway library of clones for all 19 human Wnts. An analysis comparing epitope-tagged and untagged versions of each ligand shows that despite their similar expression at the mRNA level, Wnts exhibit considerable variation in stability, processing and secretion. At least 14 out of the 19 Wnts activate beta-catenin-dependent signaling, an activity that is cell type-dependent and tracks with the stabilization of beta-catenin and LRP6 phosphorylation. We find that the core Wnt modification and secretion proteins Porcupine (PORCN) and Wntless (WLS) are essential for all Wnts to signal through beta-catenin-dependent and independent pathways. This comprehensive toolkit provides critical tools and new insights into human Wnt gene expression and function. (C) 2012 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.