Sperm FISH analysis in two healthy infertile brothers with t(15;18) unbalanced translocation: Implications for genetic counselling and reproductive management
Autor: | Jean Michel Dupont, Sandrine Leclercq, Jacques Auger, Florence Eustache, C. Dupont, Aziza Lebbar, Françoise Baverel, Dominique Le Tessier |
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Rok vydání: | 2010 |
Předmět: |
Adult
Male Infertility Reproductive Techniques Assisted Genetic counseling Genetic Counseling Chromosomal translocation Semen Biology Preimplantation genetic diagnosis Translocation Genetic Chromosome 18 Chromosome Segregation Genetics medicine Humans In Situ Hybridization Fluorescence Infertility Male Genetics (clinical) Family Health Chromosomes Human Pair 15 Karyotype General Medicine medicine.disease Spermatozoa Sperm Phenotype Karyotyping Chromosomes Human Pair 18 |
Zdroj: | European Journal of Medical Genetics. 53:127-132 |
ISSN: | 1769-7212 |
Popis: | Numerous studies have shown that balanced reciprocal or Robertsonian translocations and inversions are associated with reduced or absent sperm production. In contrast, a similar association has been rarely reported for unbalanced translocations. An unbalanced translocation, 45,XY,-15,der(18)t(15;18)(q11.2;q23), was found in two healthy infertile brothers who were referred to our hospital together with their partners for infertility. At least two routine semen analyses and karyotyping were done for each of the brothers. Sperm meiotic segregation was studied for both with a three-color FISH assay using locus-specific probes. Semen analyses showed a severe oligo-astheno-teratozoospermia with remarkably similar profiles in the two brothers. The unbalanced translocation had a deletion of 15pter-15q11.2 as well as a deletion of 18q23-18qter. The meiotic segregation was similar in the two brothers with a prevalence of alternate segregation mode. However, no phenotypic effect in the offspring can be expected only if the normal chromosomes 15 and 18 are transmitted to progeny. According to the sperm FISH results, the theoretical probability of this happening is about 25%. Based on the overall results, genetic and reproductive counselling was offered to both couples. Finally, both couples chose the alternative of donor insemination rather than preimplantation genetic diagnosis. The present study helps delineating a phenotypically silent CNV at the distal part of chromosome 18 long arm and illustrates the advantages of an integrated multidisciplinary genetic, reproductive and psychological approach to give the best possible assistance to couples who are faced with a complex and distressing genetic cause of infertility. |
Databáze: | OpenAIRE |
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