Two mosaic cases with nonfluorescent Y chromosome analysed with Y‐specific DNA probes

Abstract

Two cases of a nonfluorescent Y (Ynf) chromosome were diagnosed: one in a male, the other in a female. Both had similar complex mosaic chromosome constitutions with a 45,X cell line. DNA studies were applied in both cases for verification of the cytogenetic diagnosis. The results on the two patients were compared with data obtained from seven healthy men (46,XY), three healthy women (46,XX), two females with 46,XY karyotype, and from cell lines with 49,XXXXY and 48,XXXX chromosome constitution. The highly repetitive Y-specific DNA sequences located in the heterochromatic region of the long arm were absent in these patients. Differences in the composition of the euchromatic part of the Y chromosome were demonstrable in both patients. The highly repetitive Y-specific DNA sequences located in the heterochromatic region of the long arm were absent in these patients. Differences in the composition of the euchromatic part of the Y chromosome were demonstrable in both patients. The suggestion that the Ynf chromosome originates from a dicentric Y chromosome cannot be accepted as a complete explanation of the phenomenon, as it probably involves more complex molecular alterations of the abnormal Y chromosome. The presence of Ynf is associated with the presence of a 45,X cell line more often than in cases of simple Y chromosome deletions with the breakpoint localized in or below the Y euchromatin/heterochromatin junction.

Xp;Yp translocation inherited from the father in an SRY, RBM, and TSPY positive true hermaphrodite with oligozoospermia

“…Probes pDP61, pDP34, and M1A (DXS31/DYS22) were used as described previously 10. Probes pDP1007 and 47z were obtained from ATCC.…”

Identification and characterization of normal length nonfluorescent Y chromosomes: cytogenetic analysis, Southern hybridization and non-isotopic in situ hybridization

“…Sequences located on Yqll detected by p49f are present in our patients but absent in those reported by Kaluzewski et al (1989). The Y-specific 15.0kb fragment detected by probe pDP34 is present in the patient studied by Gemmill et al (1987) but absent in those reported by Kaluzewski et al (1988).…”

“…3). The absence of the heterochromatic part of the Y chromosome in nlynrs has also been shown by using Southern hybridization with probes specific for locus DYZ1 and DYZ2 (Gemmill et al 1987;G~inshirt-Ahlert et al 1987;Kaluzewski et al 1988). G~inshirt-Ahlert et al (1987) showed that both Yp and Yq material were present.…”

“…Consequently, unequivocal identification of a presumed Y chromosome, or a small rearranged marker replacing the second gonosome, represents a diagnostic challenge with clinical implications. Approaches used to overcome the inadequacy of routine G, R and C banding include: autoradiography (Lo Curto et al 1972;Btihler et al 1974;Hsu et al 1974;Fonatsch et al 1977;Ga~il et al 1978), meiotic studies (Casperson et al 1971), G-11 banding (Donlon Offprint requests to: F. Speleman Magenis and Donlon 1982;Almeida et al 1985Almeida et al , 1986Kosztol~nyi 1988), distamycin A-DAPI banding (Wisniewski and Hirschhorn 1982), DNA replication pattern (Camargo and Cervenka 1984), and Southern blot analysis (Gemmill et al 1987; G~inshirt-Ahlert et al 1987;Mtiller et al 1987;Stalvey and Erickson 1987;Ostrer et al 1987;Kaluzewski et al 1988).…”

Sex chromosome markers: Characterization using fluorescence in situ hybridization and review of the literature

“…In the past, both X-and Y-derived markers have been identified by several different techniques, the most widely used of which combined Y specific DNA probes and Southern blot analysis [Tho and McDonough 1977;Tho et al, 1988]. This technique has effectively identified non-fluorescent marker and dicentric Y-chromosomes [Kaluzewski et al, 1988], but Southern blot analysis with X specific probes has not been utilized frequently to identify marker X-chromosomes because of the need for polymorphic markers or dosimetry. Radioactive in situ hybridization has been used in some cases [Muller et al, 1977;Stalvey et al, 1988], but these studies involved only identification of Y-derived markers, as repetitive Y-chromosome probes were more accessible than those for the X-chromosome.…”