title: Meiotic and pedigree segregation analyses in carriers of t(4;8)(p16;p23.1) differing in localization of breakpoint positions at 4p subband 4p16.3 and 4p16.1.
abstract: OBJECTIVE
  The purpose of this study was to compare meiotic segregation in sperm cells from two carriers with t(4;8)(p16;p23.1) reciprocal chromosome translocations (RCTs), differing in localization of the breakpoint positions at the 4p subband-namely, 4p16.3 (carrier 1) and 4p16.1 (carrier 2)-and to compare data of the pedigree analyses performed by direct method.
  
  
  METHODS
  Three-color fluorescent in situ hybridization (FISH) on sperm cells and FISH mapping for the evaluation of the breakpoint positions, data from pedigrees, and direct segregation analysis of the pedigrees were performed.
  
  
  RESULTS
  Similar proportions of normal/balanced and unbalanced sperm cells were found in both carriers. The most common was an alternate type of segregation (about 52 % and about 48 %, respectively). Unbalanced adjacent I and adjacent II karyotypes were found in similar proportions about 15 %. The direct segregation analysis (following Stengel-Rutkowski) of the pedigree of carriers of t(4;8)(p16.1;p23.1) was performed and results were compared with the data of the pedigree segregation analysis obtained earlier through the indirect method. The probability of live-born progeny with unbalanced karyotype for carriers of t(4;8)(p16.1;p23.1) was moderately high at 18.8 %-comparable to the value obtained using the indirect method for the same carriership, which was 12 %. This was, however, markedly lower than the value of 41.2 % obtained through the pedigree segregation indirect analysis estimated for carriers of t(4;8)(p16.3;p23.1), perhaps due to the unique composition of genes present within the 4p16.1-4p 16.3 region.
  
  
  CONCLUSIONS
  Revealed differences in pedigree segregation analysis did not correspond to the very similar profile of meiotic segregation patterns presented by carrier 1 and carrier 2. Most probably, such discordances may be due to differences in embryo survival rates arising from different genetic backgrounds.
authors.affiliation: Department of Clinical Genetics, Medical University of Białystok, Waszyngtona 13, 15-089, Białystok, PO Box 22, Poland. midro@umb.edu.pl.
authors.forename: Alina T
authors.initials: AT
authors.lastname: Midro
authors.affiliation: Department of Medical Genetics, Università Cattolica Sacro Cuore, Rome, Italy.
authors.forename: Marcella
authors.initials: M
authors.lastname: Zollino
authors.affiliation: Department of Reproductive Biology and Stem Cells, Institute of Human Genetics, Polish Academy of Sciences, Strzeszyńska 32, 60-479, Poznań, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Wiland
authors.affiliation: Department of Clinical Genetics, Medical University of Białystok, Waszyngtona 13, 15-089, Białystok, PO Box 22, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Panasiuk
authors.affiliation: Department of Clinical Genetics, Medical University of Białystok, Waszyngtona 13, 15-089, Białystok, PO Box 22, Poland.
authors.forename: Piotr S
authors.initials: PS
authors.lastname: Iwanowski
authors.affiliation: Department of Medical Genetics, Università Cattolica Sacro Cuore, Rome, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Murdolo
authors.affiliation: Department of Genetics, Medical University of Wrocław, Wrocław, Poland.
authors.forename: Robert
authors.initials: R
authors.lastname: Śmigiel
authors.affiliation: Department of Genetics, Medical University of Wrocław, Wrocław, Poland.
authors.forename: Maria
authors.initials: M
authors.lastname: Sąsiadek
authors.affiliation: Department of Child Neurology, Medical University of Silesia, Katowice, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Pilch
authors.affiliation: Department of Reproductive Biology and Stem Cells, Institute of Human Genetics, Polish Academy of Sciences, Strzeszyńska 32, 60-479, Poznań, Poland. kurpimac@man.poznan.pl.
authors.forename: Maciej
authors.initials: M
authors.lastname: Kurpisz
mesh_terms: D000328:Adult; D056905:Chromosome Breakpoints; D020090:Chromosome Segregation / Q000235:genetics*; D002894:Chromosomes, Human, Pair 4 / Q000235:genetics*; D005260:Female; D005817:Genetic Counseling; D006579:Heterozygote; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008297:Male; D008540:Meiosis / Q000235:genetics*; D010375:Pedigree; D013094:Spermatozoa / Q000473:pathology; D014178:Translocation, Genetic / Q000235:genetics*; D014314:Trisomy / Q000235:genetics; D054877:Wolf-Hirschhorn Syndrome / Q000235:genetics / Q000473:pathology
keywords: FISH mapping; Genetic counseling; Meiotic segregation pattern; Pedigree segregation analysis; Reciprocal chromosome translocation