Three cases showed 47,XXY karyotype consistent with Klinefelter syndrome, one case with 47,XYY, one case with 45,X/46,XX mosaicism, two cases with pericentric inversions of chromosome 1 and Y, one case of t(X;Y) involving the pseudo-autosomal region and the SRY gene confirmed by molecular cytogenetic techniques and two cases of apparently balanced reciprocal translocation involving autosomes. This evidence concerns the gene SRY and Klinefelter syndrome.