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Genotype-phenotype correlations in XX males and their bearing on current theories of sex determination
- Source :
- Human Genetics. 84
- Publication Year :
- 1990
- Publisher :
- Springer Science and Business Media LLC, 1990.
-
Abstract
- Clinical, chromosomal and molecular studies of a group of 15 XX males confirm the presence of two main groups. A Y + ve group of ten patients exhibit sex reversal as the result of transfer of the distal end of the short arm of the Y chromosome, including testis determining factors, to the short arm of one X-chromosome, presumably by accidental crossing-over in paternal meiosis. The ten patients have Klinefelter's syndrome but differ from XXY cases in that they are short and shown no impairment of intelligence. The four Y-ve XX males have no demonstrable Y sequences and differ from Y + ve cases in abnormality of the external genitalia and invariable gynaecomastia; in this, they more closely resemble XX true hermaphrodites than XY males. These observations on Y - ve XX males and an additional exceptional Y + patients suggest that the ZFY locus is not essential for male differentiation and is not the primary testis determining factor. Male sex determination in sporadic, and familial Y-ve XX males and true hermaphrodites is likely to be the result of mutation in an X-linked TDF gene and its consequent escape from the constraints of X-inactivation. It seems premature to abandon the dosage model of sex determination on the recent evidence that ZFX does not show dosage compensation.
- Subjects :
- Male
Sex Determination Analysis
medicine.medical_specialty
Gonad
Dosage compensation
Genotype
Male sex determination
Cytogenetics
Locus (genetics)
Sex reversal
Biology
Y chromosome
Klinefelter Syndrome
Phenotype
Testis determining factor
medicine.anatomical_structure
Endocrinology
Karyotyping
Internal medicine
Genetics
medicine
Humans
Genetics (clinical)
Subjects
Details
- ISSN :
- 14321203 and 03406717
- Volume :
- 84
- Database :
- OpenAIRE
- Journal :
- Human Genetics
- Accession number :
- edsair.doi.dedup.....e20ab67bf3cc798cb86d10a56bdfb00f