title: Indisputable double paternity in dizygous twins.
abstract: OBJECTIVE
  To report a case of heteropaternal superfecundation.
  
  
  METHODS
  Case report.
  
  
  METHODS
  University paternity laboratory.
  
  
  METHODS
  Father, mother, and a set of twins.
  
  
  METHODS
  Blood typing conventional markers, as well as polymerase chain reaction loci and restriction fragment length polymorphism loci of DNA.
  
  
  METHODS
  Heteropaternal superfecundation was demonstrated after paternity investigation.
  
  
  RESULTS
  The probability of paternity for twin 1 was 99.9999998%, whereas that for twin 2 was excluded on the basis of the following tests: Fy, Pi, human leukocyte antigen (HLA)-DQA1, D1S80, D17S5, HBGG, D5S110, D2S44, and D10S28.
  
  
  CONCLUSIONS
  Dizygous twins can have different biologic fathers, as demonstrated in this case. According to published data, the frequency of twins with different fathers is probably underestimated, at least in small selected populations such as those of paternity suits.
authors.affiliation: Department of Legal Medicine, Faculty of Medicine, University of Granada, Spain. EGIRELA@GOLIAT.UGR.ES
authors.forename: E
authors.initials: E
authors.lastname: Girela
authors.forename: J A
authors.initials: JA
authors.lastname: Lorente
authors.forename: J C
authors.initials: JC
authors.lastname: Alvarez
authors.forename: M D
authors.initials: MD
authors.lastname: Rodrigo
authors.forename: M
authors.initials: M
authors.lastname: Lorente
authors.forename: E
authors.initials: E
authors.lastname: Villanueva
mesh_terms: D001788:Blood Grouping and Crossmatching; D004247:DNA / Q000032:analysis*; D005260:Female; D005819:Genetic Markers; D006683:HLA-DQ Antigens / Q000235:genetics; D059848:HLA-DQ alpha-Chains; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D010334:Paternity; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D011336:Probability; D014429:Twins, Dizygotic
chemical_list: D005819:Genetic Markers; D006683:HLA-DQ Antigens; D059848:HLA-DQ alpha-Chains; C069050:HLA-DQA1 antigen; D004247:DNA