title: [45,X/46,XY/47,XXY chromosome mosaicism as a cause of hypergonadotropic hypogonadism diagnosed in late middle age].
abstract: HISTORY AND FINDINGS ON EXAMINATION: A 62-year-old man complaining of increasingly painful swelling in both breasts over the previous 6 months was admitted to hospital because an endocrine tumour or paraneoplasia was suspected. Unmarried and childless he had always been well except for mild diabetes treated with glibenclamide. On examination both breasts were enlarged with easily palpable glandular tissue; the testes were small and atrophic. Hair growth and distribution were normal.
  
  
  METHODS
  Serum testosterone concentration was low (1.3 ng/ml), while luteinizing and follicle-stimulating hormones (27.3 mU/ml and 95 mU/ml, respectively) were raised. Chromosome analysis revealed 45,X/46,XY/47,XYY mosaicism without evidence of structural aberrations. Mammography showed true gynecomastia without signs of malignancy.
  
  
  METHODS
  Hypergonadotrophic hypogonadism having been diagnosed the patient was given substitution treatment with 250 mg testosterone, 250 mg i.m. every 3 weeks. The concentrations of luteinizing and follicle-stimulating hormones became normal and the gynecomastia regressed over the subsequent 6 months.
  
  
  CONCLUSIONS
  Mosaicism of the sex chromosomes should be considered in the differential diagnosis of late-onset hypogonadism, even in phenotypically unremarkable men.
authors.affiliation: Klinik für Innere Medizin, Institut für Humangenetik der Medizinischen Universität, Lübeck.
authors.forename: B
authors.initials: B
authors.lastname: Kreft
authors.forename: M
authors.initials: M
authors.lastname: Greiwe
authors.forename: E
authors.initials: E
authors.lastname: Schwinger
authors.forename: A
authors.initials: A
authors.lastname: Peters
mesh_terms: D000367:Age Factors; D005640:Follicle Stimulating Hormone / Q000097:blood; D006061:Gonadal Dysgenesis, 46,XY / Q000175:diagnosis; D006060:Gonadal Dysgenesis, Mixed / Q000175:diagnosis / Q000235:genetics* / Q000628:therapy; D006062:Gonadotropins / Q000097:blood; D006177:Gynecomastia / Q000209:etiology*; D006801:Humans; D007006:Hypogonadism / Q000175:diagnosis / Q000235:genetics* / Q000628:therapy; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008875:Middle Aged; D009030:Mosaicism; D013739:Testosterone / Q000627:therapeutic use; D014997:XYY Karyotype / Q000175:diagnosis
chemical_list: D006062:Gonadotropins; D013739:Testosterone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone
vernacular_title: Chromosomenmosaik 45,X/46,XY/47,XYY als Ursache eines im höheren Lebensalter festgestellten hypergonadotropen Hypogonadismus.