2. Academic Validation
  3. Biallelic pathogenic variants in the lanosterol synthase gene LSS involved in the cholesterol biosynthesis cause alopecia with intellectual disability, a rare recessive neuroectodermal syndrome

Biallelic pathogenic variants in the lanosterol synthase gene LSS involved in the cholesterol biosynthesis cause alopecia with intellectual disability, a rare recessive neuroectodermal syndrome

  • Genet Med. 2019 Sep;21(9):2025-2035. doi: 10.1038/s41436-019-0445-x.
Thomas Besnard 1 2,  Natacha Sloboda 3,  Alice Goldenberg 4,  Sébastien Küry 5 6,  Benjamin Cogné 5 6,  Flora Breheret 5,  Eva Trochu 5,  Solène Conrad 5,  Marie Vincent 5 6,  Wallid Deb 5 6,  Xavier Balguerie 7,  Sébastien Barbarot 8,  Geneviève Baujat 9,  Tawfeg Ben-Omran 10,  Anne-Claire Bursztejn 11,  Virginie Carmignac 12 13,  Alexandre N Datta 14,  Aline Delignières 15,  Laurence Faivre 12 13,  Betty Gardie 6 16,  Jean-Louis Guéant 3,  Paul Kuentz 12 13,  Marion Lenglet 6 16,  Marie-Cécile Nassogne 17,  Vincent Ramaekers 18,  Rhonda E Schnur 19,  Yue Si 19,  Erin Torti 19,  Julien Thevenon 20,  Pierre Vabres 12 13,  Lionel Van Maldergem 21 22,  Dorothea Wand 23,  Arnaud Wiedemann 3,  Bertrand Cariou 6,  Richard Redon 6,  Antonin Lamazière 24,  Stéphane Bézieau 5 6,  Francois Feillet 3,  Bertrand Isidor 25 26
Affiliations

Affiliations

  • 1 CHU de Nantes, Service de Génétique Médicale, Nantes, France. thomas.besnard@chu-nantes.fr.
  • 2 L'institut du thorax, INSERM, CNRS, UNIV Nantes, CHU de Nantes, Nantes, France. thomas.besnard@chu-nantes.fr.
  • 3 INSERM, UMR 1256 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), Nancy, France.
  • 4 Department of Genetics, Rouen University Hospital, Normandy Centre for Genomic and Personalized Medicine, Rouen, France.
  • 5 CHU de Nantes, Service de Génétique Médicale, Nantes, France.
  • 6 L'institut du thorax, INSERM, CNRS, UNIV Nantes, CHU de Nantes, Nantes, France.
  • 7 Department of Dermatology, University Hospital Center of Rouen, Rouen, France.
  • 8 CHU de Nantes, Department of Dermatology, Nantes, France.
  • 9 Department of Medical Genetics, INSERM UMR 1163, Paris Descartes-Sorbonne Paris Cité University, IMAGINE Institute, Necker Enfants Malades Hospital, Paris, France.
  • 10 Section of Clinical and Metabolic Genetics, Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar.
  • 11 Dermatology department, hôpital Brabois, Vandœuvre-Lès, Vandœuvre-lès-Nancy, France.
  • 12 Centre de Genetique et Centre de Reference Anomalies du Développement et Syndromes Malformatifs de l'Est, FHU-TRANSLAD, CHU Dijon, Dijon, France.
  • 13 UMR-Inserm 1231 GAD Team, Genetique des Anomalies du Développement, Université de Bourgogne Franche-Comte, Dijon, France.
  • 14 Department of Pediatric Neurology and Developmental Medicine, University of Basel Children's Hospital (UKBB), Basel, Switzerland.
  • 15 CH Auray-Vannes, Hôpital Bretagne Atlantique, Service de Pediatrie, Vannes, France.
  • 16 Ecole Pratique des Hautes Etudes, PSL Research University, Paris, France.
  • 17 Pediatric Neurology Unit, Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Brussels, Belgium.
  • 18 Center of Autism and Department of Genetics, University Hospital Liege (CHU), Liège, Belgium.
  • 19 GeneDx, 207 Perry Parkway, Gaithersburg, MD, USA.
  • 20 Centre de Génétique, Hôpital Couple-Enfant, CHU de Grenoble-Alpes, La Tronche, France.
  • 21 Centre de génétique humaine, Université de Franche-Comté, Besançon, France.
  • 22 Integrative and Cognitive Neurosciences Research Unit EA481, University of Franche-Comté, Besançon, France.
  • 23 Department Medical Genetic and Pathology, University Hospital of Basel (USB), Basel, Switzerland.
  • 24 Laboratory of Mass Spectrometry, INSERM ERL 1157, CNRS UMR 7203 LBM, Sorbonne Universités-UPMC, CHU Saint-Antoine, Paris, France.
  • 25 CHU de Nantes, Service de Génétique Médicale, Nantes, France. bertrand.isidor@chu-nantes.fr.
  • 26 L'institut du thorax, INSERM, CNRS, UNIV Nantes, CHU de Nantes, Nantes, France. bertrand.isidor@chu-nantes.fr.
PMID: 30723320 DOI: 10.1038/s41436-019-0445-x
Abstract

Purpose: Lanosterol synthase (LSS) gene was initially described in families with extensive congenital cataracts. Recently, a study has highlighted LSS associated with hypotrichosis simplex. We expanded the phenotypic spectrum of LSS to a recessive neuroectodermal syndrome formerly named alopecia with mental retardation (APMR) syndrome. It is a rare autosomal recessive condition characterized by hypotrichosis and intellectual disability (ID) or developmental delay (DD), frequently associated with early-onset epilepsy and other dermatological features.

Methods: Through a multicenter international collaborative study, we identified LSS pathogenic variants in APMR individuals either by exome Sequencing or LSS Sanger Sequencing. Splicing defects were assessed by transcript analysis and minigene assay.

Results: We reported ten APMR individuals from six unrelated families with biallelic variants in LSS. We additionally identified one affected individual with a single rare variant in LSS and an allelic imbalance suggesting a second event. Among the identified variants, two were truncating, seven were missense, and two were splicing variants. Quantification of Cholesterol and its precursors did not reveal noticeable imbalance.

Conclusion: In the Cholesterol biosynthesis pathway, lanosterol synthase leads to the cyclization of (S)-2,3-oxidosqualene into lanosterol. Our data suggest LSS as a major gene causing a rare recessive neuroectodermal syndrome.

Keywords

LSS; alopecia; cholesterol pathway; early-onset epileptic encephalopathy; intellectual disability.

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