title: Clinical and hormonal features of selective follicle-stimulating hormone (FSH) deficiency due to FSH beta-subunit gene mutations in both sexes.
abstract: OBJECTIVE
  To report the clinical, hormonal, and molecular features of a female adolescent with selective FSH deficiency. In addition, a complete review of previous cases is provided, focusing on hormonal aspects.
  
  
  METHODS
  Clinical study.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  A 16-year-old girl with primary amenorrhea and poor breast development due to isolated FSH deficiency.
  
  
  METHODS
  Blood drawing before and after GnRH stimulation and pelvic ultrasound examination.
  
  
  METHODS
  Gonadotropin and E(2) measurements and sequencing of the FSH beta-subunit gene.
  
  
  RESULTS
  The patient was referred for primary amenorrhea and partial breast development (Tanner III). Her basal and GnRH-stimulated LH levels were elevated (31 IU/L and 98 IU/L, respectively), whereas her FSH levels were undetectable (<1 IU/L) in both conditions. Estradiol levels were low (<13 pg/mL). Automatic sequencing showed a nucleotide substitution of C for A in exon 3, resulting in a homozygous nonsense mutation in amino acid position 76 (Tyr76X) of the FSH beta-subunit.
  
  
  CONCLUSIONS
  The Tyr76X mutation of the FSH beta-subunit was associated with a partial phenotype of FSH deficiency. To date, only four loss-of-function mutations of the FSH beta-subunit have been described in eight patients with undetectable serum FSH and high serum LH levels. Therefore, this unusual hormonal profile strongly suggests a defect in the FSH beta-subunit in both sexes.
authors.affiliation: Endocrinology Development Unit, Hormone and Genetic Laboratory, LIM 42, University of São Paulo School of Medicine, São Paulo, Brazil.
authors.forename: Karina
authors.initials: K
authors.lastname: Berger
authors.forename: Haroldo
authors.initials: H
authors.lastname: Souza
authors.forename: Vinicius Nahime
authors.initials: VN
authors.lastname: Brito
authors.forename: Catarina Brasil
authors.initials: CB
authors.lastname: d'Alva
authors.forename: Berenice Bilharinho
authors.initials: BB
authors.lastname: Mendonca
authors.forename: Ana Claudia
authors.initials: AC
authors.lastname: Latronico
mesh_terms: D000293:Adolescent; D000328:Adult; D000568:Amenorrhea / Q000097:blood / Q000235:genetics; D019943:Amino Acid Substitution; D005260:Female; D037201:Follicle Stimulating Hormone, beta Subunit / Q000097:blood / Q000172:deficiency* / Q000235:genetics*; D006801:Humans; D007247:Infertility, Female / Q000097:blood / Q000235:genetics*; D007248:Infertility, Male / Q000097:blood / Q000235:genetics*; D008297:Male; D010641:Phenotype
chemical_list: D037201:Follicle Stimulating Hormone, beta Subunit