Sr. Soares et al., Acrocentric chromosome disomy is increased in spermatozoa from fathers of Turner syndrome patients, HUM GENET, 108(6), 2001, pp. 499-503
The aim of the present study was to investigate whether there was an increa
se of aneuploidy in the sperm from fathers of Turner syndrome patients of p
aternal origin who, in a previous study, showed an elevated incidence of XY
meiotic nondisjunction. Sperm disomy frequencies for chromosomes 4, 13, 18
, 21 and 22 were assessed by fluorescence in situ hybridisation in four of
these individuals. As a group, the Turner syndrome fathers showed a general
increase in disomy frequencies for chromosomes 13, 21 and 22, with a stati
stically significant increase in disomy frequencies for chromosomes 13 and
22 in one of the fathers and for chromosome 21 in two of them. Data from a
previous work carried out by us in two fathers of Down syndrome patients of
paternal origin also revealed increased sperm disomy frequencies for chrom
osomes 13, 21 and 22. Pooled as one group, these six fathers of aneuploid o
ffspring of paternal origin had a statistically significant increase in the
frequency of nondisjunction for these chromosomes with respect to control
individuals. Our findings indicate that there may be an association between
fathering aneuploid offspring and increased frequencies of aneuploid sperm
atozoa. Such increases do not seem to be restricted to the chromosome pair
responsible for the aneuploid offspring. Acrocentric chromosomes and other
chromosome pairs that usually show only one chiasma during meiosis seem to
be more susceptible to malsegregation.