Search results for "Sex reversal"
showing 9 items of 9 documents
FGFR2mutation in 46,XY sex reversal with craniosynostosis
2015
Patients with 46,XY gonadal dysgenesis (GD) exhibit genital anomalies, which range from hypospadias to complete male-to-female sex reversal. However, a molecular diagnosis is made in only 30% of cases. Heterozygous mutations in the human FGFR2 gene cause various craniosynostosis syndromes including Crouzon and Pfeiffer, but testicular defects were not reported. Here, we describe a patient whose features we would suggest represent a new FGFR2-related syndrome, craniosynostosis with XY male-to-female sex reversal or CSR. The craniosynostosis patient was chromosomally XY, but presented as a phenotypic female due to complete GD. DNA sequencing identified the FGFR2c heterozygous missense mutatio…
Physiological problems of teleost ambisexuality
1988
The normal occurrence of spontaneous sex inversion among teleosts is a recent item within current concepts on vertebrate reproductive physiology. Investigations on the subject are mostly descriptive and deal with morphological and behavioral aspects. The concept of social control of sex inversion has been received with great interest. However, research on physiological processes that take place inside a fish when it changes sex must be rated as fragmentary. Steroid hormones are supposed to play a major role in sex inversion. But a cause and effect relationship has not yet been established. More experimental studies on more types of ambisexual species are badly needed. Future work will show …
A cost of Wolbachia-induced sex reversal and female-biased sex ratios: decrease in female fertility after sperm depletion in a terrestrial isopod.
2004
A number of parasites are vertically transmitted to new host generations via female eggs. In such cases, host reproduction is an intimate component of parasite fitness and no cost of the infection on host reproduction is expected to evolve. A number of these parasites distort host sex ratios towards females, thereby increasing either parasite fitness or the proportion of the host that transmit the parasite. In terrestrial isopods (woodlice), Wolbachia bacteria are responsible for sex reversion and female-biased sex ratios, changing genetic males into functional neo-females. Although sex ratio distortion is a powerful means for parasites to increase in frequency in host populations, it also …
Sex reversal from functional disomy of Xp: Prenatal and post-mortem findings.
2008
Translocations involving the short arms of the X and Y chromosomes are uncommon and are often associated with anomalies in gonadal development. Segmental duplications of the X chromosome interfere with the formation of the testis in patients with a 46,XY karyotype. The gene products located within the duplicated segment, when present in double dose, may affect on male sex development. We report on a fetus with karyotype 46,XY,der (14)t(X;14) (p10;p10)dn. Attached to chromosome 14 is the entire short arm of the X chromosome. Therefore, the fetus is affected with a disomy of Xp, resulting in complete male to female sex reversal, as well as other structural defects. To the best of our knowledg…
The occurrence of serological H-Y antigen (Sxs antigen) in the diandric protogynous wrasse, Coris julis (L.) (Labridae, Teleostei)
1987
Abstract The serological sex-specific (Sxs) antigen (previously called ‘H-Y antigen’) has been shown, in various vertebrate species ranging from fish to mammals, to be characteristic of the heterogametic sex. We studied a protogynous hermaphrodite, Coris julis , in order to examine whether the change of a female to a secondary male also involves a change in the Sxs-antigen phenotype. The (homogametic) females of this species were found to be Sxs negative, while both primary and secondary males were Sxs positive. This was true not only for gonads but also for nongo-nadal tissues. The administration of androgen to females is known to cause sex inversion in this species; we were able to demons…
17beta-hydroxysteroid dehydrogenase-3 deficiency: a rare endocrine cause of male-to-female sex reversal.
2006
Deficiency of 17beta-hydroxysteroid dehydrogenase type 3 (17beta-HSD3), due to mutations in the gene encoding the enzyme, results in a rare autosomal recessive form of male-to-female sex reversal. Mutated genes encode an abnormal enzyme with absent or reduced ability to convert Delta4-androstenedione to testosterone in the testis. Affected individuals are genetically males who developed internal male Wolffian structures but female external genitalia. Such individuals are usually raised as females and diagnosis is made at puberty, when they show virilization. Correct diagnosis is mandatory to optimize treatment and follow-up. In the present paper we report the clinical history, endocrine eva…
Identification of a new nonsense mutation (Tyr129Stop) of the SRY gene in a newborn infant with XY sex-reversal.
2004
Point mutations and deletions of SRY gene have been described in several cases of XY gonadal dysgenesis. To date, most of these mutations affect the HMG domain of SRY which plays a central role in DNA binding activity of SRY. We report on a non-mosaic XY sex-reversed newborn girl (completely female external genitalia). The direct sequencing of SRY showed a new nonsense mutation in a codon of SRY gene flanking the 3' end of the HMG domain: a thymine is replaced by a guanine at position +387 in codon 129, resulting in the replacement of the amino acid tyrosine (TAT) by a stop codon (TAG). The new mutation of this patient provides further evidence to support the functional importance of the pu…
17β-Hydroxysteroid dehydrogenase-3 deficiency: From pregnancy to adolescence
2009
OBJECTIVE: Aim of this study is to report on basal clinical phenotype and follow up after diagnosis, of patients with 17beta-hydroxysteroid-dehydrogenase type 3 (17beta-HSD3) deficiency in Italy. SETTING: Pediatric Endocrine Departments, University Hospitals. PATIENTS: The cases of 5 Italian subjects affected by 17beta-HSD3 deficiency are presented in this study. INTERVENTIONS: Laboratory and genetic assessment. Gonadectomy and female sex assignment (4 patients) or GnRH analog therapy to regress puberty and gender identity disorder (1 patient). RESULTS: Presentation lasted from pregnancy (pre-natal diagnosis of a 46,XY fetus with female external genitalia) to infancy (inguinal hernia contai…
Can Sex Inversion Be Environmentally Induced?
1980
Among teleosts simultaneous hermaphroditism and spontaneous sex inversion (either protogyny or protandry) occur in many families that inhabit tropical and subtropical marine waters. The tooth-carp Rivulus marmoratus is unique among these in being self-fertilizing. Most studies are descriptive work on gonad histology and reproductive behavior. Experimental investigations are scanty and do not yet provide fruitful ideas that might help to understand what is occurring in a fish when it changes sex. Behavioral observations and experiments led to the hypothesis that in certain coral reef fish sex inversion may be under social control. The term sex inversion requires closer examination in order t…