A case report of an XX male with complete masculinization but absence of the SRY gene

A 34-year old man with complete masculinization and a history of several years of infertility was referred to us for genetic reviewing. His semen analysis showed azoospermia. Conventional chromosomal analysis indicates a 46,XX karyotype, molecular analyses excluded the presence of SRY (the sex-determining region of the Y chromosome) gene. This case is one of the rare cases reported in the literature in whom testicular differentiation and complete virilization were found in a 46,XX chromosomal constitution, with the absence of SRY gene. This finding suggests that other genes downstream from SRY play an important role in sex determination. Through reporting this rare case and reviewing previous literatures, the aim of this report is to highlight the value of genetically screening all males with azoospermia who present for evaluation of infertility, since the phenotype does not always correlate with the genotype.     

一例罕见SRY阴性46,XX,inv(9)男性

目的:探讨46,XX男性性反转综合征的临床表现和遗传学基础。方法:对1例46,XX,inv(9)(p11q13)男性不育患者进行系统检查,包括精液分析、血清激素和性腺组织活检,PCR法分析SRY基因和Y染色体上包括AZF区域的23个特异性位点,用FISH技术进一步证实患者核型及SRY的缺失,同时检测与性腺分化相关的SOX9和DMRT1基因内部的STR位点,以观察有无基因剂量的改变。结果:外周血淋巴细胞染色体核型分析为46,XX,inv(9)(p11q13)。Y染色体上SRY和其它23个特异位点均为阴性。未发现SOX9和DMRT1基因剂量改变。性腺组织活检证实为发育不良的睾丸组织。由于睾丸组织DNA模板提取失败,故未能检测睾丸组织的特异性位点。结论:本病例的性反转不是由SRY基因转移引起的。性别决定和分化的机制目前还不完全清楚,除了SRY等已知的基因外,可能还存在其它未知但重要的性别决定基因。     

A comparative genomic hybridization study in a 46,XX male

OBJECTIVE: To identify Y chromosome material in an azoospermic male with an XX karyotype.DESIGN: Case report. SETTING: Faculty of medicine and Centro de Patologia Celular (CPC) medical center. PATIENT(S): A 33-year-old man with infertility. INTERVENTION(S): G-banding, fluorescence in situ hybridization (FISH), polymerase chain reaction (PCR), and comparative genomic hybridization (CGH). MAIN OUTCOME MEASURE(S): FISH for X and Y chromosomes, PCR for the SRYgene and amelogenin gene in the Xp (AMGX) and (AMGY), and losses or gains with CGH. RESULT(S): FISH analysis using X and Y chromosome-specific probes showed an X chromosome containing Y chromosome sequences on the top of the short arm; this Y chromosome region was not visible by conventional cytogenetic analysis. PCR amplification of DNA showed the presence of the sex-determining region of the Y chromosome (SRY) and the amelogenin gene in the pseudoautosomal boundary of the X chromosome (AMGX). CGH confirmed the presence of the chromosome region Yp11.2-pter and detected the presence of the two otherwise normal X chromosomes. CONCLUSION(S): The two Xpter (XPAR1) pseudoautosomal regions present in this XX male suggest the need to reevaluate XX males using CGH and PCR to characterize the clinical variability in XX males due to genes other than those located on the Y chromosome.     

Clinical, cytogenetic, and molecular analysis with 46,XX male sex reversal syndrome: case reports

Purpose

To investigate the clinical characteristics of different categories of sex-reversed 46,XX individuals and their relationships with chromosomal karyotype and the SRY gene.

Methods

Chromosome karyotyping for peripheral blood culture and multi-PCR and FISH were performed.

Results

Endocrinological data showed that their endocrine hormone levels were similar to that observed for Klinefelter syndrome, with higher FSH and LH levels and lower T levels. Chromosome karyotyping for peripheral blood culture revealed 46, XX complement for 11 males. Molecular studies showed that there were locus deletions at SY84, SY86, SY127, SY134, SY254 and SY255 in AZF on chromosome Y in 9 cases, with the SRY gene present at the terminus of the X chromosome short arm. In one case, besides 6 locus deletions in AZF, there was also SRY gene deletion. In another case, there were locus deletions only at SY254 and SY255, with SY84, SY86, SY127 SY134 loci and SRY present.

Conclusions

The majority (10/11) of 46,XX males were SRY positive, with the SRY gene translocated into the terminus of the X chromosome short arm. These patients were caused mainly by an X/Y chromosomal inter-change during paternal meiosis, leading to the differentiation of primary gonads into testes. Only a single patient (1/11) was SRY-negative, in which there might be some unknown downstream genes involved in sex determination.     

A rare case of gonadal agenesis with paramesonephric derivatives in a patient with a normal female karyotype

OBJECTIVE: To report a rare case of gonadal agenesis with rudimentary paramesonephric ducts derivatives in a female with a 46,XX normal karyotype. DESIGN: Case study. SETTING: National Institute of Health. PATIENT(S): An 18-year-old female with primary amenorrhea and lack of secondary sexual development. INTERVENTION(S): Clinical, gynecological, endocrine, and genetic evaluation. Laboratory studies conducted included measurement of pituitary, ovary, and thyroid hormones; analyses of G-banded chromosomes in peripheral blood and fibroblast cultures; search for genomic Y-chromosome DNA by fluorescence in situ hybridization and molecular biology techniques; X-ray, ultrasonography, echocardiographic and laparoscopic studies for the assessment of bone age, and genitourinary and other associated malformations. MAIN OUTCOME MEASURE(S): Clinical, hormonal, anatomical, and genetic characteristics of the patient. RESULT(S): The studies performed confirmed a prepubertal female with hypergonadotrophic hypogonadism, bilateral gonadal agenesis, a rudimentary uterus and fallopian tubes, a normal vagina, kidney, and urinary tract structures, and a 46,XX normal karyotype. The search for centromeric Y-chromosome DNA and SRY and ZFY genes was negative. CONCLUSION(S): A primary deficiency confined to the gonadal blastema and the nearby coelomic epithelium is proposed as an alternative embryologic mechanism to explain the occurrence of this singular sexual developmental defect.     

Birth of two infants with normal karyotype after intracytoplasmic injection of sperm obtained by testicular extraction from two men with nonmosaic Klinefelter's syndrome.

OBJECTIVE: To report two births of a healthy male and a healthy female baby after use of testicular spermatozoa from two patients with nonmosaic Klinefelter's syndrome. DESIGN: Case report. SETTING: General academic hospital with IVF center and university institute of human genetics. PATIENT(S): Two couples with primary infertility in which the men had secretory azoospermia and nonmosaic 47,XXY karyotype. Both women had a normal karyotype and no gynecologic abnormalities. INTERVENTION(S): ICSI was performed using testicular spermatozoa after ovarian stimulation and transvaginal ultrasonography-guided oocyte pick-up. MAIN OUTCOME MEASURE(S): Normal fertilization, embryo cleavage, clinical pregnancy outcome, and peripheral blood karyotype of the newborn. RESULT(S): In each case, 13 metaphase II oocytes were injected, of which 7 fertilized normally. Three good-quality embryos (4-cell stage) were transferred into the uterine cavity. Both women conceived, and normal pregnancies followed. Genetic analysis of the neonates revealed normal 46,XX and 46,XY karyotypes. CONCLUSION(S): These case reports reaffirm that patients with nonmosaic Klinefelter's syndrome produce normal spermatozoa with fertilization potential. Although it is premature to make conclusions about the rate of transmission of this aneuploidy because of the low number of the published cases, this report substantiates the idea that rates of transmission of this gonosomal aneuploidy are low.     

性畸形四例遗传学分析

在细胞遗传学核型分析的基础上，利用Ｙ染色性体决定区基因（ｓｅｘ－ｄｅｔｅｒｍｉｎｉｇｒｅｇｉｏｎｏｆｔｈｅＹｃｈｒｏｍｏｓｏｍｅ，ＳＲＹ）探针，对４例性畸形病例进行了Ｓｏｕｔｈｅｒｎ杂交分析。同时运用ＳＲＹ编码区的特异性引物，对其基因组ＤＮＡ进行了聚合酶链式反应（ＰＣＲ）扩增检测。结果显示：１例４６，ＸＹ女性伴性腺发育不良症；１例４５，ＸＯ／４６，ＸＹ女性表现为Ｔｕｒｎｅｒ综合征，未检出ＳＲＹ特异     

Case report: Y;6 translocation with deletion of 6p

Translocations between the Y chromosome and an autosome are rare. We report a phenotypic male with a translocation between the Y chromosome and chromosome 6p, leading to partial 6p monosomy and XX male syndrome. He is the second child to be reported with this karyotype. Phenotypic findings included growth retardation, severe developmental delay, a Dandy-Walker malformation, cardiac and urogenital abnormalities, bilateral hearing loss, cleft palate, severe kyphoscoliosis, minor digital anomalies, and a hypoplastic phallus. Craniofacial dysmorphism consisted of dolichocephaly, hypertelorism, down-slanting palpebral fissures, depressed nasal bridge and a tented upper lip. Cytogenetic analysis showed the karyotype 46,XX,der(6)t(Y;6)(p11.2;p23).ish der(6)(SRY+,6pTEL48-). The effects of partial monosomy 6p are discussed and compared to other patients with interstitial and terminal 6p deletions.     

Breakpoint of a Y chromosome pericentric inversion in the DAZ gene area. A case report

BACKGROUND: The presence of a spermatogenesis locus (gene or gene complex) in the euchromatic region of the long arm of the Y chromosome (Yq11), defined as azoospermia factor on the basis of gross structural rearrangement, was detected. The gene family responsible for different spermatogenetic defects is "deleted in azoospermia" (DAZ). CASE: A 34-year-old man had oligozoospermia, and a cytogenetic analysis carried out on peripheral lymphocytes with G banding revealed a 46,X, inv(Y)(p11q11)karyotype. The relation between the chromosomal breakpoint and the DAZ gene was more precisely defined by a fluorescent in situ hybridization technique. We revealed two signals for the DAZ gene, weaker than normal, one on the short arm and the other on the long arm of the Y chromosome, indicating that the breakpoint was located at the DAZ gene level. CONCLUSION: This is the first report documenting a chromosomal pericentric inversion with disruption in the DAZ gene area. We hope to obtain information on whether the disruption affects a functional zone of the gene and correlates with oligospermia at the chromosomal level.     

46 XX male syndrome: a case report

INTRODUCTION: 46 XX male syndrome (de la Chapelle syndrome) is a rarely seen genetic disorder causing male infertility. It is generally a result of unequal crossing over between X and Y chromosomes. CASE REPORT: A 26-year-old infertile male was referred to the Urology Department. He had normal external male genital phenotype and secondary sex characters. No gynecomastia was noted. At physical examination soft and atrophic testes were palpated. Laboratory analysis and testis biopsies indicated nonobstructive azospermia. Chromosomal analysis showed 46 XX karyotype. CONCLUSION: In the literature, there are various phenotypic properties of 46 XX male patients. Thus, translocation of the sex determining region (SRY) the gene probably cannot be the only reason for XX male syndrome. There might be some other abnormalities leading to de la Chapelle syndrome.     

Discordant prenatal diagnosis of trisomy 21 due to mosaic structural rearrangements of chromosome 21

OBJECTIVES: Trisomy 21 mosaicism associated with a structural rearrangement of chromosome 21 is uncommon. We report on two prenatal diagnoses in which karyotypes showed mosaicism with an aberrant cell line, including a structural rearrangement of chromosome 21. METHODS: Both these cases were associated with increased nuchal translucency. Conventional and molecular cytogenetic analyses were performed on uncultured and cultured trophoblast and amniotic fluid cells. RESULTS: In Case 1, analysis of trophoblast cells revealed an abnormal karyotype of 47,XX,+mar.ish der(13/21)(D13Z1/D21Z1+)/46,XX. The amniocentesis showed a free non-mosaic trisomy 21. In Case 2, the trophoblast direct analysis showed a normal male karyotype whereas the long-term culture revealed a mosaicism for a dicentric long-arm isochromosome 21: 46,XY,idic(21)(p11)/45,XY,-21/46,XY. Amniocentesis showed an unbalanced non-mosaic karyotype 46,XY,idic(21)(p11) resulting therefore in trisomy for the long arm of chromosome 21. CONCLUSION: Our cases underline the importance of combining the direct analysis and long-term culture of trophoblast and emphasise the need for confirmatory studies in other tissues when mosaicism of structural rearrangement is encountered in chorionic villi. The meiotic and mitotic mechanisms of formation of these structural rearrangements of chromosome 21 are discussed.     

Prenatal diagnosis of a 45,X male with a SRY-bearing chromosome 21

Male phenotype associated with a 45,X karyotype is an infrequent finding. We present a case diagnosed prenatally on amniocentesis performed for maternal age. The male phenotype was associated with a translocation of a distal part of Yp including the pseudoautosomal SHOX gene and SRY gene on the short arm of a chromosome 21. By DNA analysis we could show that the X chromosome was of maternal origin and that the breakpoint was in interval 3 of the Y chromosome. Mechanisms and genetic counselling are discussed based on a review of published cases of 45,X and XX males.     

Chromosomal mosaicism for isochromosome 11q confined to CVS direct preparations

OBJECTIVE: To analyse the discrepancy between the karyotype in direct preparations of chorionic villus sampling (CVS) and the fetal karyotype and its possible fetal phenotypic repercussion. METHODS: The karyotype was obtained from direct and cultured preparations of CVS. FISH was performed in direct CVS preparations and in four different areas of term placenta. RESULTS: Karyotype and FISH analysis in CVS revealed a 46,XX/47,XX,+i(11q) cell line. Cultured CVS preparations showed a 46,XX karyotype. Cytogenetic studies in term placenta did not reveal the abnormal cell line. Molecular studies did not detect uniparental disomy for chromosome 11 in the fetus. CONCLUSION: The fetus, at birth, had no phenotypic abnormalities. IUGR was not present during gestation, in accordance with the low proportion of aneuploid cells in term placenta, and UPD for chromosome 11 was not observed.     

Two unusual chromosome aberrations ascertained by sonographic anomalies

We describe two cases of sonographic abnormalities associated with unusual chromosomal aberrations. Case 1 presented with a cystic hygroma at 12 weeks' gestation. Cytogenetic analysis revealed an unbalanced complex chromosome rearrangement implicating chromosomes 6, 13 and 21 (karyotype: 47,XX,t(6;21;14)(q14;q21;q21)mat,+21) and corresponding to a complete trisomy 21. This anomaly resulted from malsegregation of a maternal balanced three-way translocation. For case 2, an alobar holoprosencephaly was identified by ultrasonography at 23 weeks' gestation. Chromosomal analysis showed a recombinant rec (13), dup q chromosome, secondary to unequal crossing-over of a paternal pericentric inversion of chromosome 13, giving rise to partial trisomy 13q (karyotype: 46,XX,rec(13)dup(13q)inv(13)(p11q21)pat). These two cases illustrate the role of ultrasound in leading to detection not only of foetal chromosomal aberrations but also of rare balanced chromosomal rearrangements presented by one of the two parents.     

单纯性染色体18p部分三体综合征患儿的产前遗传学诊断和文献回顾

目的探讨单纯性染色体18P部分三体综合征患者的产前诊断特点。方法联合运用传统染色体核型分析和染色体微阵列(chromosome microarray analysis,CMA)基因芯片技术对家系成员行染色体核型分析和基因组拷贝数变异检测。结果胎儿羊水染色体核型结果为46,XY,der(18),父母双方染色体核型均未见异常;胎儿基因芯片检测结果为arr[hg19]18p11.31p11.21(3,521,718-15,099,116)×3,即胎儿基因组18号染色体短臂p11.31p11.21区域存在11.58 Mb的片段重复,父母双方基因芯片结果均为阴性,提示该胎儿的18号染色体结构重排为新发生的。结论在一个有不良生育史家系的胎儿中检出一个罕见新发的单纯性染色体18p部分三体变异,这是世界少见的单纯性染色体18p部分三体综合征的产前病例报道。联合运用传统染色体核型分析和C M A基因芯片技术在预防不良产史家系中胎儿出生缺陷的产前诊断中具有重要的临床应用价值。     

Endometrial stromal sarcoma with a sole t(X;17) chromosome change: report of a case and review of the literature

BACKGROUND: Endometrial stromal sarcomas (ESSs) exhibit varying degrees of malignancy and heterogeneity at the karyotypic level. The biological mechanisms that contribute to tumorigenesis of ESS are still largely unknown. CASE: A 33-year-old woman suffering from ESS was treated primarily surgically. Cytogenetic evaluation of the primary uterine nodule and metastatic tumor showed 46,XX,t(X;17)(p11:q23) karyotype in all metaphases analyzed. Normal endometrial cells exhibited 46,XX karyotype. Fluorescence in situ hybridization analysis confirmed the presence of the reciprocal t(X;17) translocation and allowed for the positioning of the chromosome X breakpoint distal to SSX1 gene loci. CONCLUSIONS: Our report of a previously undescribed sole cytogenetic translocation in an advanced stage of ESS might identify a cytogenetically distinct subgroup of ESS and help to reveal genes involved in ESS tumorigenesis.     

Prenatal detection of an interstitial deletion in 4p15 in a fetus with an increased nuchal skin fold measurement

OBJECTIVES: The detection of an increased nuchal translucency (NT) or nuchal fold (NF) measurement is associated with an increased risk of common aneuploidies. Only rarely is it associated with other types of chromosome abnormalities. We report the prenatal finding of an increased NF in a fetus with an interstitial 4p deletion. METHODS: Standard karyotype analysis was followed by FISH with research generated BAC probes to precisely map the 4p deletion. RESULTS: The karyotype of the fetus was determined to be 46,XX,del(4)(p15.2p16.1) by G-banding analysis and was refined to 46,XX,del(4) (p15.1p15.32) after FISH analysis. The breakpoints were narrowed to 150 kb regions on each side. The deletion is approximately 14.5 Mb, containing approximately 47 genes. CONCLUSIONS: We report a case of an increased NF measurement associated with a 4p deletion. A literature review revealed a previous case of a 4p deletion in a fetus with an increased NT. Since chromosome deletions are rarely associated with an increased NT or NF, we believe it is significant that a 4p deletion has now been found in two unrelated cases. We mapped the deletion with BAC probes, generating a list of possible candidate genes involved in the pathogenesis of increased nuchal skin folds.     

Absence of microdeletions in the Y chromosome in patients with a history of cryptorchidism and azoospermia or oligospermia

OBJECTIVE: To determine if cryptorchidism is associated with microdeletions of interval 6 of the Y chromosome, we evaluated this locus in men with a history of cryptorchidism with and without azoospermia or oligospermia and in a control group. DESIGN: Clinical study. SETTING: Academic research environment. PATIENT(S): Men in whom surgical treatment of cryptorchidism had been performed in childhood and healthy control male subjects. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Genotyping of interval 6 of the Y chromosome. RESULT(S): Analysis of semen obtained from men treated for cryptorchidism in childhood showed azoospermia or oligospermia in 14 of 38 (37%) men. No microdeletions were identified with polymerase chain reaction amplification of 17 distinct sequence tagged sites located on the long arm of the Y chromosome and the sex determining region on Y (SRY) gene. CONCLUSION(S): Microdeletions of interval 6 of the Y chromosome were not detected in either the formerly cryptorchid or in the healthy subjects. Although we cannot exclude the possibility of point mutations, we conclude that cryptorchidism or cryptorchidism associated with azoospermia or oligospermia is not due to microdeletions involving interval 6 of the Y chromosome.     

X-Y translocations and sex differentiation

Translocations involving the X and Y chromosomes are often associated with anomalies of gonadal development. Transfer of Yp sequences, including the testis-determining SRY gene, to the terminal portion of the short arm of the X chromosome is associated with 46,XX maleness and in rare cases 46,XX true hermaphroditism. Three classes of XX males have been defined on the basis of the extent of Y material transferred to the X chromosome. In one class, the transfer of material involves aberrant recombination between two highly homologous genes, PKRX and PKRY, and there is evidence to suggest that this interchange is influenced by the Y chromosome background. Other types of X-Y translocations associated with anomalies of sex differentiation include Xp-Yq translocations, which result in a functional disomy of Xp sequences including the DSS locus and are associated with 46,XY complete or partial gonadal dysgenesis. In rare cases Yp-Xq translocations have been described in association with 46,XX maleness.