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Biomedical subjects

W R Breg

Publications and source records attributed to W R Breg.

At least 73 records · Page 4Linked to original sources

Serologic detection of a y-linked gene in xx males and xx true hermaphrodites.

To test the hypothesis that H-Y antigen (present on both somatic and germ cells in normal males but not normal females) is essential for testicular differentiation, we studied four XX males and three XX true hermaphrodites. Blood cells from six subjects and cultured gonadal fibroblasts from a seventh expressed H-Y antigen. Since expression of this antigen requires the presence of a gene normally carried by the Y chromosome, this gene, and perhaps additional Y chromosomal material, should have been present in the genome of these subjects. In one patient this presence is accounted for by a Y-to-X translocation, detectable by chromosome banding. In another a normal Y chromosome was present in a minor population of cells. In the remaining five, no karyotypic abnormality was detectable. Immunologic detection of H-Y antigen is a sensitive test for the presence of the Y chromosome or of its male-determining segment.

Adult↗

Expression of H-Y antigen in human males with two Y chromosomes.

To determine whether the gene that controls the expression of H-Y ("male") antigen on human cells is Y-linked, we have compared the H-Y antigen level in normal males with that in three males with two Y chromosomes. Leukocytes from one XXYY and two XYY males express more H-Y antigen than leukocytes from normal XY males. We conclude that a structural gene or positive regulatory gene for H-Y antigen is on the human Y chromosome. Testing for the H-Y antigen may be of benefit in patients who have signs of masculinization but who lack an identifiable Y chromosome. Positive results for the H-Y antigen would be tentative evidence that the corresponding region of the Y chromosome was present, perhaps as part of a translocation, despite the absence of a typical Y chromosome.

Absorption↗

Trisomy 8 mosaicism syndrome.

Chromosome 8 is the largest autosome thus far found to be trisomic among liveborn infants. Trisomy 8 "mosaicism" syndrome (T8mS) consists primarily of individuals whose chromosome complement is mosaic for chromosome 8 (T8m), i.e., patients with a chromosomally normal cell line in addition to the trisomic 8 cell line, and a few known individuals with full trisomy 8 (T8), i.e., each cell observed contains an extra chromosome 8. Reported cases of both types share a number of common features and thus have helped to delineate a new syndrome. Common features of T8mS include mild-to-moderate mental retardation, strabismus, osseous and soft tissue abnormalities, lowset and/or malformed ears, broad bulbous nose, palate deformity, various types of congenital cardiovascular disorders, hydronephrosis, cryptorchidism, and characteristic dermatoglyphics. Since chromosomal mosaicism is often present in this syndrome it is not surprising that considerable phenotypic variation exists. The present report of one of the youngest individuals yet described with T8m adds two more physical findings (dense corneal clouding and a heretofore undescribed clavicular deformity) to the constellation of abnormalities associated with T8mS. On the basis of the phenotypic and cytogenetic findings in this and 17 similar patients previously reported it is proposed that T8mS is a distinct clinical entity.

Abnormalities, Multiple↗