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Biomedical subjects

E Vilain

Publications and source records attributed to E Vilain.

At least 37 records · Page 2Linked to original sources
PubMed1995

t(15;17) hypergranular acute promyelocytic leukemia (M3) developing into a t(3;6) M3 without t(15;17) at relapse.

This report describes a case of acute promyelocytic leukemia (APL) M3. At diagnosis, the specific t(15;17) translocation was observed. After chemotherapy including retinoic acid, a complete remission was achieved and the karyotype became normal. At relapse of the M3 leukemia, the t(15;17) clone was no longer observed but a t(3;6) translocation was then detected. Several hypotheses for this unusual cytogenetic course of APL are discussed.

Adult↗
PubMed1994

Dysgerminoma in a pure 45,X Turner syndrome: report of a case and review of the literature.

There is a high risk of neoplasm in dysgenetic gonads. Classically, in Turner syndrome, only patients with 45, X/46, XY mosaicism karyotype or with a fragment of Y chromosome (45, X+mar) are at risk of developing gonadal tumor. A case of a dysgerminoma arisen on the dysgenetic gonad of a 45, X Turner patient in the absence of Y chromosome material at cytogenetic and molecular biology analysis is reported. Five cases of gonadal tumor with a pure 45, X chromosome constitution have been previously reported in the literature. In these cases only cytogenetic analysis was performed. This is the first case of an ovarian tumor in a 45, X Turner syndrome in which the presence of Y material can be ruled out by an extensive molecular analysis of the blood and the tumor.

Adult↗
PubMed1994

Clinical and anatomical spectrum in XX sex reversed patients. Relationship to the presence of Y specific DNA-sequences.

OBJECTIVE: Testicular differentiation can occur in the absence of the Y chromosome giving XX sex-reversed males. Although Y chromosomal sequences can be detected in the majority of male subjects with a 46,XX karyotype, several studies have shown that approximately 10% of patients lack Y material including the SRY gene. The aim of this study was to see if the classification of XX sex-reversed individuals into three groups, Y-DNA-positive phenotypically normal XX males, Y-DNA-negative XX males with genital ambiguities and Y-DNA-negative true hermaphrodites can be applied to our cases. DESIGN: Endocrinological and genetic studies were conducted in 20 XX sex-reversed patients. PATIENTS: Twenty patients with various phenotypes were studied. They were between 20 days and 35 years old. Ten presented ambiguous external genitalia (Prader's stages II to IV). After laparotomy or gonadal biopsy, the diagnosis was 46,XX true hermaphroditism in five, and XX male in 15. MEASUREMENTS: Blood samples were obtained from all patients for hormonal and molecular studies. Basal levels of testosterone, oestradiol and pituitary gonadotrophins were measured by RIA. In addition, two stimulation tests were performed: gonadotrophin stimulation with GnRH and testicular stimulation with hCG. Several Y-specific DNA sequences of the short arm of the Y chromosome were analysed by Southern blot and polymerase chain reaction methods. RESULTS: In this study, three categories of XX sex-reversed individuals were observed: phenotypically normal males with or without gynaecomastia, males with genital ambiguities, and true hermaphrodites. Endocrinological data were similar in XX males and in true hermaphrodites. Testosterone levels exhibited normal (n = 9) or decreased (n = 11) values. The hCG response was low. FSH and LH were elevated in 13 patients. Molecular analysis in ten patients showed varying amounts of Y material including the Y boundary and SRY. Ten patients with various phenotypes lacked Y chromosomal DNA. There was no relation between Leydig cell function (as indicated by testosterone levels before or after hCG stimulation) and the presence of Y chromosome material. CONCLUSION: Although the presence of Y-specific DNA generally results in a more masculinized phenotype, exceptions do occur. In the Y-DNA-negative group, complete or incomplete masculinization in the absence of SRY suggests a mutation of one or more downstream non-Y, testis-determining genes.

Adolescent↗
PubMed1994

[Brief antiseptic application of iodine in neonatal intensive care units: effects on thyroid function].

BACKGROUND: Transient thyroid dysfunction with its adverse effects of diminished levels of thyroid hormone on mental development has been reported in neonates whose skin has been cleaned with iodine-containing substances. We report the results of thyroid screening in iodine-exposed neonates and controls. POPULATION AND METHODS: Thirty seven neonates admitted to an intensive care unit from 1990 to 1992 and whose medical condition required umbilical catheterization were included in the study. There were 21 neonates (six term and 15 preterm) for whom the area around the umbilicus was cleansed with iodine antiseptic and 16 controls (four term and 12 preterm) for whom the antiseptic used did not contain iodine. Levels of serum free T3 and T4, and TSH were determined by 7 days after catheterization as did urinary iodine and creatinine concentrations. RESULTS: Iodine-exposed neonates had significant high levels of TSH (P < 0.01) and low free T3 (P < 0.05); levels of free T4 were lower than in controls but not significantly. Urinary iodine excretion was significantly increased. The increase in TSH disappeared between 15 and 30 days after iodine application. CONCLUSION: Application of iodine antiseptics may cause transient thyroid dysfunction in neonates leading to propose the use of non iodinated substances with similar antibacterial efficacy.

Anti-Infective Agents, Local↗
PubMed1994

[Study of sex determination gene (SRY) in 46,XY gonadal dysgenesis].

During mammalian embryogenesis, the presence of the SRY gene determines the bipotential gonad to develop as a testis. 46,XY sex reversal has been described in man. It is associated with an essentially female phenotype and a streak gonad. In a collaborative study, we analysed 36 patients with a 46,XY sex reversal. The testis determining region of the Y chromosome was analysed by Southern blotting and by DGGE analysis of the SRY open reading frame (orf). We found a total of 7 mutations in the testis determining region including the SRY gene. This brings to 19 the total number of mutations in SRY associated with sex reversal. No relationship was found between the SRY status and the presence or absence of gonadoblastoma. However, a correlation was observed between the SRY genotype and the histology of the gonad. A mutant in SRY is associated with a completely dysgenetic gonad. The presence of immature testicular tubules is usually observed when SRY is normal. These latter results suggest the existence of as yet unidentified testis determining genes.

DNA-Binding Proteins↗
PubMed1993

A regulatory cascade hypothesis for mammalian sex determination: SRY represses a negative regulator of male development.

The mammalian Y chromosome carries the SRY gene, which determines testis formation. Here we review data on individuals who are XX but exhibit male characteristics: some have SRY; others do not. We have analyzed three families containing more than one such individual and show that these individuals lack SRY. Pedigree analysis leads to the hypothesis that they carry recessive mutations (in a gene termed Z) that allow expression of male characteristics. We propose that wild-type Z product is a negative regulator of male sex determination and is functional in wild-type females. In males, SRY product represses or otherwise negatively regulates Z and thereby allows male sex determination. This hypothesis can also explain other types of sex reversal in mammals, in particular, XY females containing SRY. Some of these individuals may have mutations at the Z locus rendering them insensitive to SRY. Recessive mutations (such as the polled mutation of goats) leading to sex reversal are known in a variety of animals and might be used to map and ultimately clone the human Z gene.

Animals↗
PubMed1993

Hormonal and molecular genetic findings in 46,XX subjects with sexual ambiguity and testicular differentiation.

Ten patients were studied who had sexual ambiguity having in common a 46.XX karyotype and testicular tissue. They were aged from one month to 23 years; some of them were followed through puberty. Eight cases were sporadic and two familial. They were divided into two groups according to finding of surgery and histology: 46, XX males with sexual ambiguity and 46 XX true hermaphrodites (TH). They were no differences in phenotypes (except uterus and ovotestis in TH). The endocrinological data were identical in the two groups: testosterone levels were in the normal range during puberty, then decreased in adulthood. Gonadotrophins were above the normal range at mid-puberty. Gonadal biopsies, regardless of the ovarian part of the ovotestis, were identical in two groups, i.e., normal in the youngest patients, then spermatogonia disappeared afterwards and dysgenesis became obvious. In one case, the ovarian zone of the ovotestis was only detected on serial cuts after gonadectomy. Southern blots displayed the presence of Y specific material in tow cases (PABY-SRY-PO.9). Otherwise, in all other patients, there was the lack of any Y sequences without any differences between the two groups. These data suggests that 46, XX males with sexual ambiguity and 46 XX true hermaphrodites may be alternative expressions of two genetic defects: one, a minimal interchange between Yp and Xp, another, a mutation of an autosomal testis determining factor for the patients without Y detectable material.

Adolescent↗
PubMed1993

Pathology of 46,XY pure gonadal dysgenesis: absence of testis differentiation associated with mutations in the testis-determining factor.

Individuals with 46, XY pure gonadal dysgenesis present with a completely female phenotype. These individuals develop bilateral streak gonads and have normal Müllerian structures. The apparent absence of testicular tissue in these individuals suggests a mutation in the initial steps of the male sex-determining pathway. A candidate gene for the primary signal in this pathway was recently cloned (SRY) which encodes a protein with a DNA-binding capacity. In a study of 14 XY females with pure gonadal dysgenesis harbouring SRY, we analysed the histology of the gonads and compared it to the presence or absence of mutations in the SRY open reading frame (SRY-orf). The histological analysis revealed two distinct groups of streak gonads. In the first group, the gonad was composed of exclusively ovarian-like stroma, with sclero-hyaline nodules in some areas. No tubules were observed. The gonads in the second group were composed of undifferentiated stroma harbouring either tubules or a rete structure. This suggests that in the latter group some differentiation (towards testis formation) has occurred, whereas in the first group ovarian differentiation has been interrupted. Individuals with mutations in the SRY-orf were found to have streak gonads of the first group, whereas most of the remaining XY females without detectable mutation in the SRY-orf had streak gonads belonging to the second group. On the basis of histology, it may be possible to distinguish between mutations in the sex-determining or sex-differentiation pathways. We suggest that SRY may play a role in rete testis formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Familial case of 46,XX male and 46,XX true hermaphrodite associated with a paternal-derived SRY-bearing X chromosome.

The human testis-determining gene was recently isolated from a 35 kb region on the human Y chromosome which was present in four sex-reversed individuals, three XX males and one true hermaphrodite. One of the XX males and the true hermaphrodite were sibs. A more detailed molecular analysis of these two patients and their family for Y-DNA sequences including the testis-determining gene, SRY was performed. The father was found to harbor two copies of SRY, one on his Y chromosome and the other on his X chromosome located at Xp22 determined by in situ hybridization. Somatic cell hybrids were generated from peripheral blood lymphocytes. Analysis of Y chromosome-negative somatic cell hybrids from the XX male, the true hermaphrodite and their father, revealed that both the X and Y pseudo-autosomal boundaries were present. The present of both boundaries suggests than an unequal interchange of X and Y material occurred with the cross-over breakpoint located within the X pseudo-autosomal region. The paternal SRY-bearing X chromosome was transmitted to two of his children, a 46 XX true hermaphrodite and a 46,XX male. The presence of SRY on an X chromosome associated with two sex phenotypes strongly suggests that the phenotypic variability was caused by differential inactivation of the SRY-bearing X chromosome, thereby influencing SRY expression.

Base Sequence↗
PubMed1992

XY sex reversal associated with a deletion 5' to the SRY "HMG box" in the testis-determining region.

The human testis-determining factor resides within a 35-kilobase (kb) region of the Y chromosome immediately adjacent to the pseudoautosomal boundary. A candidate gene for human sex determination (SRY) was isolated in this region. Here, we describe a study of 25 cases of XY females with pure gonadal dysgenesis for mutations on the Y chromosome short arm, including SRY. Southern blotting revealed a sex-reversed female harboring a deletion extending from approximately 8 kb from the pseudoautosomal boundary of the Y chromosome to at least 33 kb and no more than 60 kb upstream, toward the centromere. The deletion begins no more than 1.8 kb upstream from the first ATG of the SRY open reading frame present in the clone pY53.3. To our knowledge, no mutation has been described previously outside the SRY "HMG box" on the short arm of the Y chromosome, which is associated with sex reversal. Since the 5' extent of the SRY transcriptional unit has not been defined, the deletion may remove upstream exons of SRY and/or transcriptional regulatory motifs, either situation resulting in lack of testicular development. It cannot be formally excluded that the mutation removes a second locus, independent of SRY, that is critical for sex determination. Denaturant gradient gel electrophoresis analysis of the SRY open reading frame in the remaining 24 cases revealed de novo single base-pair transitions in the SRY conserved domain in 4 cases.

Amino Acid Sequence↗
PubMed1992

[Sex genetics].

The sex gene SRY has recently been characterized after years of research during which the candidate genes HY and ZFY were excluded. SRY does have all the characteristics expected of the sex gene: it is located on chromosome Y of all mammals, including man; it is specifically expressed in male gonads during early embryonic development mutations and deletions have been found in 46,XY women with gonadal dysgenesis; the Sry gene is present in the vast majority of XX men and finally, transgenic experiments in the mouse have shown that Sry reverses the sex of XX mice. All this demonstrates that SRY is truly the sex gene, but some abnormalities of sex determination in humans remain shrouded in mystery. There are 46,XX men who do not carry the sex gene, and some 46,XX SRY positive true hermaphrodites in whose gonads ovarian and testicular tissues coexist. Finally, SRY is apparently normal in the majority of pure gonadal dysgenesis.

Crossing Over, Genetic↗
PubMed1992

XY sex reversal associated with a nonsense mutation in SRY.

Sex determination in humans is mediated through the expression of a testis-determining gene on the Y chromosome. In humans, a candidate gene for the testis-determining factor (TDF) that encodes a protein with a putative DNA-binding motif and has been isolated is termed SRY. Here we describe an XY sex-reversed female with pure gonadal dysgenesis who harbors a de novo nonsense mutation in the SRY open reading frame (SRY-orf). This single-basepair substitution results directly in the formation of a termination codon in the putative SRY DNA-binding motif, presumably leading to a nonfunctional gene product. This brings the number of reported XY sex-reversed females with de novo mutations in the known SRY-orf to three, each occurring in the putative DNA-binding domain. This provides further evidence to support SRY being TDF in humans and also indicates the functional importance of the putative DNA-binding domain of the SRY protein.

Base Sequence↗
PubMed1992

The sole presence of the testis-determining region of the Y chromosome (SRY) in 46,XX patients is associated with phenotypic variability.

Four cases of XX patients with testis development are reported. The aim of this study was to describe their clinical features and to see if there was any relationship between phenotypes and the presence of Y material. Several human Y-derived sequences including the SRY probe were used to analyze the DNA of the patients. Yp material including the pseudo-autosomal region and SRY was detected. The cases reported in this study confirm that XX true hermaphrodites cannot be distinguished from XX males on the basis of their genotypes. There is no relationship between clinical and anatomical phenotypes and the presence of Y material. SRY does not warrant a complete and normal testis differentiation. Although similar in some features with Klinefelter's syndrome patients, XX males exhibit specific clinical manifestations due to the lack of Y-specific genes.

Adolescent↗
PubMed1992

Familial case with sequence variant in the testis-determining region associated with two sex phenotypes.

The human Y chromosome encodes a testis-determining factor (TDF) which is responsible for initiating male sex determination. Recently a region of the Y chromosome (SRY) was identified as part of the TDF gene. We have identified a three-generation family (N) in which all XY individuals have a single base-pair substitution resulting in a conservative amino acid change in the conserved domain of the SRY open reading frame. Three individuals are XY sex-reversed females, and two are XY males. Several models are proposed to explain association between a sequence variant in SRY and two sex phenotypes.

Adolescent↗