Analysis of chromosomal equipment in spermatozoa of a 46,XY/47,XY/+8 male by means of multicolour fluorescent in situ hybridization: confirmation of a mosaicism and evaluation of risk for offspring

Abstract

Trisomy 8 is generally associated with chromosomal mosaicism and occurs de novo, with relatively well-defined clinical manifestations, ranging from minimal effects to severe malformations. Mosaicism is often difficult to ascertain and the confirmation of diagnosis requires several chromosomal investigations on a variety of tissues. We present a case of mosaic trisomy 8 fortuitously found in a healthy 30-year-old man during a cytogenetic investigation for several spontaneous abortions: 8% of the lymphocyte metaphases showed a 47,XY,+8 karyotype. Fluorescent in situ hybridization (FISH) with the probes pJM.128 and L1.84 was performed on decondensed interphase spermatozoa. Of the 25000 analysed cells, 398 spermatozoa (1.59%) exhibited a hybridization pattern compatible with a chromosome 8 disomy; the frequency was higher than in either sperm control populations (0.17% and 0.21%). This result is in agreement with the existence of trisomy 8 mosaicism in the gonads and germ cells. FISH on decondensed interphase spermatozoa spreads is thus an easy non-invasive procedure that can be used to complement mosaicism diagnosis in tissue other than blood. Moreover, FISH provides interesting data for characterizing the risk for offspring.

Increased frequency of X-bearing sperm in males from an infertility clinic: analysis by two-color fluorescence in situ hybridization

“…2. Ratios of X-and Y-bearing sperm in the Lübeck group (n = 34) compared with summarized data of seven reports (total n = 53) (Chevret et al, 1995;Griffin et al, 1996;Martin et al, 1996;Martini et al, 1996;Mercier and Bresson, 1997;Rives et al, 1998;Martinez-Pasarell et al, 1999). The percentage of Y-bearing sperm is significantly lower in the Lübeck group than in the literature group (P !…”

Detection of structural abnormalities in spermatozoa of a translocation carrier t(3;11)(q27.3;q24.3) by triple FISH

“…Some studies used FISH on testis biopsies from a translocation carrier (Goldman and Hulten 1993 a, b), on epididimal spermatozoa from Robertsonian translocationbearing mice (Lowe et al 1996) and on ejaculated spermatozoa from translocation carriers (Lu et al 1994;Spriggs and Martin 1994;Mercier and Bresson 1997). However, until now, the analysis of spermatozoa of translocation carriers by FISH using centromeric probes could not discriminate gametes originating from an alternative or adjacent I segregation mode.…”

“…This technique is limited to the detection of abnormalities for the specific chromosomes analysed, but it allows rapid screening of many spermatozoa. Only few studies exist on men carrying a numerical chromosomal abnormality, such as XYY and XXY karyotypes (Han et al 1994;Martini et al 1996;Mercier et al 1996;Chevret et al 1997;Guttenbach et al 1997), and on men carrying a structural chromosomal abnormality (Lu et al 1994;Spriggs and Martin 1994;Mercier and Bresson 1997). These studies were all based on the detection of meiotic segregation modes using centromeric probes.…”

Molecular analysis of the chromosomal equipment in spermatoza of a 46, XY, t(7;8) (q11.21;cen) carrier by using fluorescence in situ hybridization

“…The FISH technique when used on human interphase spermatozoa, together with the development of reliable methods to decondense sperm chromatin, allows direct assess to the chromosomal equipment of mature gametes (Martin et al 1996;Mercier et al 1996;Mercier and Bresson 1997;Morel et al 1997;Van Hummelen et al 1996). To date, only a few cas-es of reciprocal translocation carriers have been reported by FISH, mostly because of the unavailability of specific detectable probes (Estop et al 1997;Goldman et al 1993;Lu et al 1994;Spriggs and Martin 1994;Van Hummelen et al 1997).…”