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Onoufriadis A, Cabezas A, Ng JCF, Canales J, Costas MJ, Ribeiro JM, Rodrigues JR, McAleer MA, Castelo-Soccio L, Simpson MA, Fraternali F, Irvine AD, Cameselle JC, McGrath JA. Autosomal recessive hypotrichosis with loose anagen hairs associated with TKFC mutations. Br J Dermatol 2020; 184:935-943. [PMID: 32790068 DOI: 10.1111/bjd.19481] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/07/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND Loose anagen hair is a rare form of impaired hair anchorage in which anagen hairs that lack inner and outer root sheaths can be gently and painlessly plucked from the scalp. This condition usually occurs in children and is often self-limiting. A genetic basis for the disorder has been suggested but not proven. A better understanding the aetiology of loose anagen hair may improve prevention and treatment strategies. OBJECTIVES To identify a possible genetic basis of loose anagen hair using next-generation DNA sequencing and functional analysis of variants identified. METHODS In this case study, whole-exome sequencing analysis of a pedigree with one affected individual with features of loose anagen hair was performed. RESULTS The patient was found to be compound heterozygous for two single-nucleotide substitutions in TKFC resulting in the following missense mutations: c.574G> C (p.Gly192Arg) and c.682C> T (p.Arg228Trp). Structural analysis of human TKFC showed that both mutations are located near the active site cavity. Kinetic assays of recombinant proteins bearing either of these amino acid substitutions showed almost no dihydroxyacetone kinase or D-glyceraldehyde kinase activity, and FMN cyclase activity reduced to just 10% of wildtype catalytic activity. CONCLUSIONS TKFC missense mutations may predispose to the development of loose anagen hairs. Identification of this new biochemical pathobiology expands the metabolic and genetic basis of hypotrichosis.
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Affiliation(s)
- A Onoufriadis
- St John's Institute of Dermatology, School of Basic and Medical Biosciences, Guy's Hospital, King's College London, London, UK
| | - A Cabezas
- Grupo de Enzimología, Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Medicina, Universidad de Extremadura, Badajoz, Spain
| | - J C F Ng
- Randall Centre for Cell and Molecular Biophysics, Guy's Hospital, King's College London, London, UK
| | - J Canales
- Grupo de Enzimología, Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Medicina, Universidad de Extremadura, Badajoz, Spain
| | - M J Costas
- Grupo de Enzimología, Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Medicina, Universidad de Extremadura, Badajoz, Spain
| | - J M Ribeiro
- Grupo de Enzimología, Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Medicina, Universidad de Extremadura, Badajoz, Spain
| | - J R Rodrigues
- Laboratório Associado LSRE-LCM, Escola Superior de Tecnologia e Gestão, Instituto Politécnico de Leiria, Leiria, Portugal
| | - M A McAleer
- Paediatric Dermatology, Children's Health Ireland at Crumlin, Dublin, Ireland
| | - L Castelo-Soccio
- Pediatric Dermatology, Children's Hospital of Philadelphia and University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - M A Simpson
- Department of Medical and Molecular Genetics, School of Basic and Medical Biosciences, Guy's Hospital, King's College London, London, UK
| | - F Fraternali
- Randall Centre for Cell and Molecular Biophysics, Guy's Hospital, King's College London, London, UK
| | - A D Irvine
- Paediatric Dermatology, Children's Health Ireland at Crumlin, Dublin, Ireland.,Clinical Medicine, Trinity College Dublin, Dublin, Ireland
| | - J C Cameselle
- Grupo de Enzimología, Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Medicina, Universidad de Extremadura, Badajoz, Spain
| | - J A McGrath
- St John's Institute of Dermatology, School of Basic and Medical Biosciences, Guy's Hospital, King's College London, London, UK
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Nguyen TK, Chua D, Shannon NB, Ng JCF, Tan HK. The show must go on. Br J Surg 2020; 107:e201. [PMID: 32383160 PMCID: PMC7267535 DOI: 10.1002/bjs.11684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 04/17/2020] [Indexed: 11/13/2022]
Affiliation(s)
- T K Nguyen
- Division of Surgery and Surgical Oncology, Singapore General Hospital and National Cancer Centre, Singapore
| | - D Chua
- Division of Surgery and Surgical Oncology, Singapore General Hospital and National Cancer Centre, Singapore
| | - N B Shannon
- Division of Surgery and Surgical Oncology, Singapore General Hospital and National Cancer Centre, Singapore
| | - J C F Ng
- Division of Surgery and Surgical Oncology, Singapore General Hospital and National Cancer Centre, Singapore
| | - H K Tan
- Division of Surgery and Surgical Oncology, Singapore General Hospital and National Cancer Centre, Singapore
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