SPERM CHROMOSOME ANALYSIS IN THE FATHER OF A CHILD WITH A DE-NOVO RECIPROCAL TRANSLOCATION T(11-15)(Q12-Q22) BY G-BANDING AND FLUORESCENCE IN-SITU HYBRIDIZATION
P. Colls et al., SPERM CHROMOSOME ANALYSIS IN THE FATHER OF A CHILD WITH A DE-NOVO RECIPROCAL TRANSLOCATION T(11-15)(Q12-Q22) BY G-BANDING AND FLUORESCENCE IN-SITU HYBRIDIZATION, Human reproduction, 13(1), 1998, pp. 60-64
Analysis of sperm chromosomes by G-banding and two-colour fluorescence
in-situ hybridization (FISH) was carried out in the father of a child
with a de-novo reciprocal translocation t(11;15)(q12;q22), Sperm chro
mosome complements were obtained after in-vitro fusion of zona-free ha
mster oocytes and donor spermatozoa, A total of 112 sperm complements
was first analysed by G-banding, The frequency of structural chromosom
e aberrations (9.8%) and the conservative frequency of aneuploidy (0.0
%) were not significantly different from those obtained in our control
donors, The proportions of X-bearing (53.2%) and Y-bearing (46.8%) sp
ermatozoa were not significantly different from the expected 1:1 ratio
. A total of 313 sperm complements was analysed by two-colour FISH. Th
e frequency of structural abnormalities for chromosomes 11 and 15 was
3.2 and 0.3% respectively. The frequency of rearrangements for chromos
ome 11 was statistically significant when compared with control donors
(0.4%) (P < 0.0001). No spermatozoa with the t(11;15)(q12;q22) transl
ocation were observed, showing no evidence for a germ-cell mosaicism.
These results suggest that the denovo involvement of chromosome 11 in
a structural rearrangement is not random, and that in this patient an
increased risk of de-novo structural chromosome abnormalities in furth
er offspring does exist.