title: SET binding factor 1 (SBF1) mutation causes Charcot-Marie-Tooth disease type 4B3.
abstract: OBJECTIVE
  To identify the genetic cause of an autosomal recessive demyelinating Charcot-Marie-Tooth disease type 4B (CMT4B) family.
  
  
  METHODS
  We enrolled 14 members of a Korean family in which 3 individuals had demyelinating CMT4B phenotype and obtained distal sural nerve biopsies from all affected participants. We conducted exome sequencing on 6 samples (3 affected and 3 unaffected individuals).
  
  
  RESULTS
  One pair of heterozygous missense mutations in the SET binding factor 1 (SBF1) gene (22q13.33), also called MTMR5, was identified as the underlying cause of the CMT4B family illness. Clinical phenotypes of affected study participants with CMT4B were similar, to some extent, to patients with CMT4B1 and CMT4B2. We found a similar loss of large myelinated fibers and focally folded myelin sheaths in our patients, but the actual number of myelinated fibers was different from CMT4B1 and CMT4B2.
  
  
  CONCLUSIONS
  We suggest that the compound heterozygous mutations in SBF1 are the underlying causes of a novel CMT4B subtype, designated as CMT4B3. We believe that this study will lead to mechanistic studies to discover the function of SBF1 and to the development of molecular diagnostics for CMT disease.
authors.affiliation: Department of Biological Science, Kongju National University, Gongju, Korea.
authors.forename: Khriezhanuo
authors.initials: K
authors.lastname: Nakhro
authors.forename: Jin-Mo
authors.initials: JM
authors.lastname: Park
authors.forename: Young Bin
authors.initials: YB
authors.lastname: Hong
authors.forename: Ji Hoon
authors.initials: JH
authors.lastname: Park
authors.forename: Soo Hyun
authors.initials: SH
authors.lastname: Nam
authors.forename: Bo Ram
authors.initials: BR
authors.lastname: Yoon
authors.forename: Jeong Hyun
authors.initials: JH
authors.lastname: Yoo
authors.forename: Heasoo
authors.initials: H
authors.lastname: Koo
authors.forename: Sung-Chul
authors.initials: SC
authors.lastname: Jung
authors.forename: Hyung-Lae
authors.initials: HL
authors.lastname: Kim
authors.forename: Ji Yon
authors.initials: JY
authors.lastname: Kim
authors.forename: Kyoung-Gyu
authors.initials: KG
authors.lastname: Choi
authors.forename: Byung-Ok
authors.initials: BO
authors.lastname: Choi
authors.forename: Ki Wha
authors.initials: KW
authors.lastname: Chung
mesh_terms: D000328:Adult; D002607:Charcot-Marie-Tooth Disease / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology; D059472:Exome / Q000235:genetics; D005260:Female; D006580:Genetic Carrier Screening; D005838:Genotype; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D020125:Mutation, Missense / Q000235:genetics*; D010375:Pedigree; D010641:Phenotype; D056910:Republic of Korea; D059467:Transcriptome / Q000235:genetics*; D055815:Young Adult
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; C111446:SBF1 protein, human