title: Normal sperm in a 2;2 homologous male translocation carrier.
abstract: OBJECTIVE
  Carriers of balanced structural chromosomal abnormalities are phenotypically normal but are at high risk of infertility. Translocations usually occur between two non-homologous chromosomes. When occur between homologous chromosomes, an extremely rare event, generally involve acrocentric chromosomes. We present an infertile male referred for genetic analysis with a pure balanced homologous 2;2 translocation and normal sperm in the ejaculate.
  
  
  METHODS
  Conventional cytogenetic and fluorescence in situ hybridization (FISH) were used in karyotype and sperm analysis, respectively.
  
  
  RESULTS
  Male's karyotype revealed a pure balanced translocation involving homologous chromosomes 2: 46,XY,t(2;2)(p23;q21.2). Sperm analysis by FISH revealed the presence of 15.8 % of normal and 84.2 % of abnormal spermatozoa for chromosome 2.
  
  
  CONCLUSIONS
  This is the first report of confined gonadal mosaicism in a pure homologous non-acrocentric chromosome translocation carrier. Preimplantation genetic diagnosis for chromosome 2 should be offered as a reproductive option.
authors.affiliation: Department of Genetics, Faculty of Medicine, University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal. carola@med.up.pt
authors.forename: Carolina
authors.initials: C
authors.lastname: Almeida
authors.forename: Sofia
authors.initials: S
authors.lastname: Dória
authors.forename: Maria
authors.initials: M
authors.lastname: Moreira
authors.forename: Joel
authors.initials: J
authors.lastname: Pinto
authors.forename: Alberto
authors.initials: A
authors.lastname: Barros
mesh_terms: D000328:Adult; D002889:Chromosomes, Human, Pair 2 / Q000235:genetics*; D005260:Female; D006801:Humans; D007248:Infertility, Male / Q000235:genetics*; D059785:Karyotype; D008297:Male; D011247:Pregnancy; D011248:Pregnancy Complications / Q000235:genetics; D019836:Preimplantation Diagnosis; D013091:Spermatogenesis / Q000235:genetics; D013094:Spermatozoa / Q000502:physiology*; D014178:Translocation, Genetic