Published in

Cell Press, American Journal of Human Genetics, 2(91), p. 397, 2012

DOI: 10.1016/j.ajhg.2012.07.011

Cell Press, American Journal of Human Genetics, 6(90), p. 1116, 2012

DOI: 10.1016/j.ajhg.2012.05.013

Cell Press, American Journal of Human Genetics, 5(90), p. 907-914, 2012

DOI: 10.1016/j.ajhg.2012.04.002

Links

Tools

Export citation

Search in Google Scholar

A Human Homeotic Transformation Resulting from Mutations in PLCB4 and GNAI3 Causes Auriculocondylar Syndrome

Journal article published in 2012 by Mark J. Rieder, Glenn E. Green, Sarah S. Park, Brendan D. Stamper, Christopher T. Gordon, Jason M. Johnson, Christopher M. Cunniff, Joshua D. Smith, Sarah B. Emery, Stanislas Lyonnet, Jeanne Amiel ORCID, Muriel Holder, Michael J. Bamshad, Andrew A. Heggie, Deborah A. Nickerson and other authors.
This paper is made freely available by the publisher.
This paper is made freely available by the publisher.

Full text: Download

Green circle
Preprint: archiving allowed
Upload
Orange circle
Postprint: archiving restricted
Upload
Red circle
Published version: archiving forbidden
Policy details
Data provided by SHERPA/RoMEO

Abstract

Auriculocondylar syndrome (ACS) is a rare, autosomal-dominant craniofacial malformation syndrome characterized by variable micrognathia, temporomandibular joint ankylosis, cleft palate, and a characteristic “question-mark” ear malformation. Careful phenotypic characterization of severely affected probands in our cohort suggested the presence of a mandibular patterning defect resulting in a maxillary phenotype (i.e., homeotic transformation). We used exome sequencing of five probands and identified two novel (exclusive to the patient and/or family studied) missense mutations in PLCB4 and a shared mutation in GNAI3 in two unrelated probands. In confirmatory studies, three additional novel PLCB4 mutations were found in multigenerational ACS pedigrees. All mutations were confirmed by Sanger sequencing, were not present in more than 10,000 control chromosomes, and resulted in amino-acid substitutions located in highly conserved protein domains. Additionally, protein-structure modeling demonstrated that all ACS substitutions disrupt the catalytic sites of PLCB4 and GNAI3. We suggest that PLCB4 and GNAI3 are core signaling molecules of the endothelin-1-distal-less homeobox 5 and 6 (EDN1-DLX5/DLX6) pathway. Functional studies demonstrated a significant reduction in downstream DLX5 and DLX6 expression in ACS cases in assays using cultured osteoblasts from probands and controls. These results support the role of the previously implicated EDN1-DLX5/6 pathway in regulating mandibular specification in other species, which, when disrupted, results in a maxillary phenotype. This work defines the molecular basis of ACS as a homeotic transformation (mandible to maxilla) in humans.