title: Clinical and Hormonal Features of a Male Adolescent with Congenital Isolated Follicle-Stimulating Hormone Deficiency.
abstract: OBJECTIVE
  Our aim was to describe the clinical and genetic findings in an adolescent male with isolated follicle-stimulating hormone (FSH) deficiency and demonstrate the efficacy of recombinant human FSH (rhFSH) replacement in this case.
  
  
  METHODS
  A 14.5-year-old adolescent male was referred with normal pubertal development and small testes. Serum testosterone, FSH, and luteinising hormone (LH) were measured at baseline and after gonadotropin-releasing hormone (GnRH) stimulation. Testicular biopsy was performed, and rhFSH replacement was administered for 6 months. The patient's FSHβ gene was amplified and sequenced.
  
  
  RESULTS
  Basal and GnRH-stimulated FSH levels were undetectable, in contrast with increased LH levels under both conditions. Histopathological investigation of a testicular biopsy specimen revealed a reduced number of Sertoli cells, the absence of germ cells, Leydig cell hyperplasia, and a thickened basement membrane in seminiferous tubules. The testicular size changed from 1 ml at baseline to 6 ml after 6 months of rhFSH replacement. Sequencing of the FSHβ gene exon 3 revealed a new missense mutation (c.364T>C, resulting in p.Cys122Arg) in a homozygous state in the patient; both parents and a sister carried the same mutation in a heterozygous state. We also compared our case with all similar cases published previously.
  
  
  CONCLUSIONS
  We herein described an adolescent male with isolated FSH deficiency due to a novel FSHβ gene mutation associated with a prepubertal testes size and normal virilisation.
authors.affiliation: Department of Paediatric Endocrinology, Eskisehir Osmangazi University School of Medicine, Eskisehir, Turkey.
authors.forename: Enver
authors.initials: E
authors.lastname: Şimşek
authors.forename: Luciana R
authors.initials: LR
authors.lastname: Montenegro
authors.forename: Cigdem
authors.initials: C
authors.lastname: Binay
authors.forename: Meliha
authors.initials: M
authors.lastname: Demiral
authors.forename: Mustafa Fuat
authors.initials: MF
authors.lastname: Acıkalin
authors.forename: Ana Claudia
authors.initials: AC
authors.lastname: Latronico
mesh_terms: D000293:Adolescent; D019943:Amino Acid Substitution; D005640:Follicle Stimulating Hormone / Q000097:blood / Q000172:deficiency / Q000235:genetics / Q000627:therapeutic use; D020249:Hormone Replacement Therapy; D006801:Humans; D007985:Leydig Cells / Q000378:metabolism / Q000473:pathology; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D020125:Mutation, Missense; D011994:Recombinant Proteins / Q000627:therapeutic use; D012708:Sertoli Cells / Q000378:metabolism / Q000473:pathology; D013739:Testosterone / Q000097:blood
chemical_list: D011994:Recombinant Proteins; D013739:Testosterone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone