5例性反转综合征患者SRY、SOX9、DAX1基因检测及病因分析

目的 探讨5例性反转综合征患者的发病机制.方法 对5例性反转综合征患者进行染色体核型分析,SRY、SOX9和DAX1基因检测,SRY阳性患者进行荧光原位杂交(FISH)检测.结果 5例性反转综合征患者中,4例为XX男性性反转(核型46,XX 3例;45,XX,t(13q14q)1例),1例为46,XY女性性反转.4例X...     

46,XX男性/46,XY女性综合征病例分析

目的报告2例性反转综合征病例,探讨性反转综合征的遗传学机制及性别决定基因在人类性腺分化和性别发育中的作用。方法细胞遗传学染色体核型分析以及PCR技术检测外周血SRY基因。结果病例1患者的外周血染色体核型为46,XX,SRY( )。诊断为46,XX男性性反转综合征;病例2的患者外周血染色体核型为46,XY,SRY( )。诊断为46,XY女性性反转综合征。结论细胞遗传学核型分析结合PCR技术检测SRY基因,是诊断性别发育异常患者的重要手段。SRY基因检测比Y染色体更能预示睾丸组织的存在。除SRY基因外,还存在多个参与性别决定和分化的基因,性分化异常表现高度遗传异常性。     

16例46,XX男性表型性发育异常患者的遗传学分析

目的对16例46,XX表型为男性的性发育异常患者进行遗传学分析,探讨其临床表现与核型的相关性。方法应用常规染色体G显带分析患者的核型,用荧光原位杂交(fluorescenceinsituhybridization,FISH)、聚合酶链反应(PCR)对SRY基因进行检测和定位;通过多重连接依赖性探针扩增(multiplexligation-dependentprobe amplification,MLPA)检测性别相关基因拷贝数。结果常规G显带核型分析显示16名患者染色体核型均为46,XX;其中15例存在SRY基因且均未发现突变,其SRY基因易位到X染色体的短臂;1例患者SRY缺失,MLPA未发现有性别相关基因拷贝数异常。结论隐匿的SRY基因易位到X染色体上是46,XXDSD的主要病因,SRY阴性表型为男性患者,存在传统性别决定以外的途径。     

2例SRY阳性的46,XX男性综合征患者临床及细胞分子遗传学研究

目的探讨SRY阳性的46,XX男性综合征患者的临床及细胞分子遗传学特征。方法分析2例46,XX(SRY+)男性综合征患者的临床特点,通过患者染色体核型分析、多重连接探针扩增(MLPA)、荧光原位杂交(FISH)技术,进行Y染色体微缺失的细胞和分子遗传学检测。结果 2例患者社会性别均为男性,染色体核型均为46,XX,Y染色体微缺失检测示AZF a,b,c区域均缺失,SRY基因均存在。结论 SRY基因是参与性别决定和分化的关键基因,对其进行检测有利于明确性反转综合征的临床诊断,细胞、分子遗传学研究为性发育异常患者的临床确诊和治疗提供了依据。     

性分化异常并伴有其它综合征四例的遗传学分析

目的对多种性分化异常并伴有其它综合征的患者进行细胞遗传学检查,必要的进行SRY基因分析,以探讨性别异常分化的原因.方法外用血淋巴细胞培养法检查染色体核型,聚合酶链反应法(PCR)检测SRY基因.结果1例患者染色体核型为47,XX, 21/45,X/46,XX;1例患者染色体核型为46,XX SRY基因检测阴性;另两例染色体核型为46,XX.结论染色体检查、SRY基因检测在性分化异常患者的诊断和治疗中有重要意义,并有助于阐明性分化异常的遗传本质和发病机制.     

应用FISH和PCR方法对7例性发育异常患者进行分子细胞遗传学研究

目的应用FISH和PCR方法对7例性发育异常患者进行明确的遗传学诊断,分析患者性发育异常产生的原因。方法采用CEPX-Yq21双色探针及SRY特异探针进行原位杂交,分析患者X、Y染色体及SRY基因的分布情况;PCR的方法检测Y染色体短臂SRY、ZFY基因和Y染色体长臂AZF因子,确定Y染色体的完整性。结果7例患者中,有5例社会性别为男性：染色体核型为2例46,XX,2例嵌合型46,XX／46,XY;46,XX／46,XY／47,XXY、1例45,X;2例社会性别为女性：1例46,XY,SRY基因阴性;1例46,XX,SRY阴性、ZFY基因阳性。46,XX男性患者中1例SRY基因位于Xp,1例为SRY阴性;嵌合型男性患者中1例AZF多个位点缺失,另1例AZF无位点缺失;45,X男性患者为SRY阳性。结论性染色体畸变是引起性发育异常的重要原因之一,Y染色体在性别分化中起睾丸决定作用,SRY基因是性别决定的主导基因,但不是决定全部男性化的惟一因素。     

46,XX男性和46,XX/45,X病例分析

目的探讨SRY基因在性分化和发育中的作用.方法细胞遗传学核型分析以及PCR技术检测外周血SYR基因.结果病例1的核型为46,XX,SRY( ).诊断为46,XX男性性反转综合征.病例2的核型为46,XX/45,X,SRY(-).诊断为Turner嵌合型.结论SRY基因检测比Y染色体更能预示睾丸组织的存在,是诊断性别发育异常患者的重要手段.性腺的病理取决于性腺组织的染色体核型和SRY基因.除SRY基因外,还存在多个参与性别决定和分化的基因,性分化异常表现现高度遗传异常性.     

46,XX男性综合征患者的细胞和分子遗传学研究

目的探讨SRY阳性的46,XX男性综合征患者的临床及细胞分子遗传学特征。方法对其外周血淋巴细胞进行染色体核型分析;同时提取外周血基因组DNA,进行SRY基因检测,并以正常男性及女性作对照。结果患者染色体核型为46,XX,SRY基因存在。结论基因组中存在SRY基因可能与该例46,XX男性综合征患者为男性表型密切相关,对其进行检测有利于明确性反转综合征的临床诊断,通过染色体核型分析和分子遗传学检测,可为性发育异常患者明确病因,并为其治疗提供依据。     

性分化异常患者的细胞及分子遗传学分析

目的通过对20例性分化异常患者进行细胞遗传学及分子遗传学分析,为临床诊断提供参考,并对性分化异常机制进行探讨。方法应用染色体G显带与聚合酶链反应对性分化异常患者进行染色体核型分析与SRY基因的检测。结果7例Turner综合征患者均为SRY（-）,其中1例核型为45,X/46,XY;1例45,X/47,XYY/46,XY及SRY（-）患者为嵌合型女性性反转。46,XY及SRY（＋）患者中有1例为睾丸女性化综合征、1例为XY单纯性腺发育不全、6例为男性化男性假两性畸形。而4例46,XX及SRY（-）患者为先天性肾上腺皮质增生。结论对性分化异常患者进行染色体核型分析及SRY基因检测,有利于了解该类患者的遗传学病因,为其诊断和治疗提供科学的依据。     

一例SRY阳性的46,XX男性综合征患者临床及细胞遗传学研究

目的探讨SRY阳性的46,XX男性综合征患者的临床及细胞遗传学研究。方法针对1例SRY阳性的46,XX男性综合征患者,应用多重PCR及染色体技术进行SRY、Y染色体微缺失等细胞遗传学检测。结果通过PCR扩增SRY、Y染色体微缺失发现患者SRY基因阳性,且Y染色体微缺失AZF区域AZFa、AZFb、AZFc、AZFd均缺失。染色体核型为46,XX。性激素检测示高促性腺激素性腺功能不全。结论对性发育异常的患者进行染色体核型分析和SRY基因检测,有利于了解该类患者的遗传学病因,为明确诊断和治疗提供科学依据。     

8例性发育异常患者SRY基因分析

目的对8例性发育异常患者进行细胞遗传学及分子遗传学检查以探讨性别发育异常与SRY基因关系.方法用PY3.4,X着丝粒,SRY特异探针进行荧光原位杂交,用于分析性发育异常病人Y染色体及SRY基因异位情况.聚合酶链反应(PCR)扩增SRY基因,直接测序检测SRY基因突变.结果 2例46,XX男性,1例46,XY女性,1例45,X/46,XY嵌合体及1例46,X,t(Y;Y)(p11;q11)男性患者SRY基因均为阳性,直接测序未发现SRY基因阳性患者该基因突变.剩余1例46,XX男性,1例46,XY男性及1例46,XY女性患者SRY基因为阴性.FISH技术证实2例46,XX且SRY基因阳性的男性患者SRY基因易位至X染色体短臂末端.结论 SRY基因是人类性别决定的主导基因,但尚有其他基因参与性别分化.     

Atypical XX male with the SRY gene located at the long arm of chromosome 1 and a 1qter microdeletion

Male individuals with a 46,XX karyotype have been designated as XX males. In 80% of the cases, the presence of Yp sequences, including the male sex-determining gene, SRY, has been demonstrated by molecular and/or fluorescence in situ hybridization (FISH) analyses. In most cases, Yp sequences are located on the short arm of the X chromosome, resulting from unequal recombination between Yp and Xp during paternal meiosis. Much less frequent in XX males is the localization of the SRY gene to an autosome. Here we report on the genetic investigation of an atypical XX male in which the SRY gene was located at the end of the long arm of chromosome 1. The patient, with a normal male phenotype, was referred for azoospermia. Conventional cytogenetic analysis showed a 46,XX karyotype. Molecular-cytogenetics (FISH) and molecular (PCR and MLPA) studies identified not only Yp-specific sequences located on the distal long arm of chromosome 1 but also the deletion of the subtelomeric 1qter region. A specific phenotype has been reported for a deletion of the 1qter region associated with mental retardation. The molecular investigation of the 1qter region showed that in our patient the microdeletion is more telomeric than in patients reported with mental retardation. To our knowledge, this is the first report of a XX male with the Yp region transferred to the terminal long arm of chromosome 1. This is also the first microdeletion of the subtelomeric 1qter region not associated with mental retardation.     

Molecular, cytogenetic, and clinical characterisation of six XX males including one prenatal diagnosis.

Cytogenetic analysis, fluorescent in situ hybridisation (FISH), and molecular amplification have been used to characterise the transfer of Yp fragments to Xp22.3 in six XX males. PCR amplification of the genes SRY, RPS4Y, ZFY, AMELY, KALY, and DAZ and of several other markers along the Y chromosome short and long arms indicated the presence of two different breakpoints in the Y fragment. However, the clinical features were very similar in five of the cases, showing a male phenotype with small testes, testicular atrophy, and azoospermia. All these patients have normal intelligence and a stature within the normal male range. In the remaining case, the diagnosis was made prenatally in a fetus with male genitalia detected by ultrasound and a 46,XX karyotype in amniocytes and fetal blood. Molecular analysis of fetal DNA showed the presence of the SRY gene. FISH techniques also showed Y chromosomal DNA on Xp22.3 in metaphases of placental cells. To our knowledge, this is the second molecular prenatal diagnosis reported of an XX male.     

Gene dosage imbalances in patients with 46,XY gonadal DSD detected by an in-house-designed synthetic probe set for multiplex ligation-dependent probe amplification analysis

The development of a testis requires the proper spatiotemporal expression of the SRY gene and other genes that act in a dosage-sensitive manner. Mutations in the SRY gene account for only 10–15% of patients with 46,XY gonadal disorder of sex development (DSD). To enable the diagnostics of deletions and duplications of genes known to be involved in different forms of DSD, we developed a synthetic probe set for multiplex ligation-dependent probe amplification (MLPA) analysis. Here, we report the results from the analysis of 22 patients with 46,XY gonadal DSD. The analysis with the DSD probe set has led to the identification of two copy number variations, an 800-kb NR0B1 ( DAX1 ) locus duplication on Xp21 in a patient with isolated partial gonadal dysgenesis and a duplication of the SRD5A2 gene that represents a rare normal variant. The described MLPA kit represents an optimal complement to DNA sequence analysis in patients with DSD, enabling screening for deletions and duplications of several genes simultaneously. Furthermore, the second identification of an NR0B1 locus duplication in a patient with isolated gonadal dysgenesis, without dysmorphic features and/or mental retardation, highlights the importance of evaluating NR0B1 duplication in patients with gonadal dysgenesis.     

Cytogenetic and molecular study of a premature male infant with 46,XX derived from ICSI: case report

We investigated the aetiology of the male phenotype in a premature infant derived from ICSI with a 46,XX karyotype. A karyotypically normal couple underwent ICSI because of obstructive azoospermia in the male partner. Sperm were retrieved by testicular sperm extraction (TESE), cryopreserved, and later used for ICSI. The pregnancy after ICSI ended at 20 weeks. A normal-appearing male was delivered but he did not survive. Umbilical cord blood and placenta were sampled and used for molecular and cytogenetic investigation. The 46,XX karyotype from G-banding in this male infant correlated to a balanced female comparative genomic hybridization (CGH) profile in placental tissue. No PCR amplification of SRY on the p arm of the Y chromosome was observed while fluorescence in-situ hybridization (FISH) with the SRY probe also could not detect the gene in cord blood or placental tissues. CGH and FISH, with X and Y centromeric probes, failed to detect mosaicism in the trophoblast, stroma and amnion. Skewed X-chromosome inactivation (81%) was found in the chorionic villi. The molecular and cytogenetic studies indicated a 46,XX male infant without the SRY gene or 46,XX/XY mosaicism. The possible mechanism in this SRY-negative XX male by ICSI is discussed.     

Multiplex ligation-dependent probe amplification assay for diagnosis of congenital adrenal hyperplasia

Mutations in the CYP21A2 gene encoding the 21-hydroxylase enzyme account for >90% of congenital adrenal hyperplasia (CAH) cases. Approximately 20% of mutant alleles carrying large deletion/duplication have also been reported. Herein, we describe the use of the multiplex ligation-dependent probe amplification (MLPA) method for convenient and rapid detection of deletions/duplications in the CYP21A2 gene. We used MLPA to analyze the gene dose of CYP21A2 MLPA in 13 Korean patients who previously underwent direct sequencing for the molecular diagnosis of CAH. The MLPA assays identified 5 patients with CYP21A2 deletions; all 5 patients carried a single mutant allele peak in sequence analysis. These results demonstrate the diagnostic usefulness of MLPA to detect CYP21A2 deletions/duplications for diagnosis of CAH.     

Autosomal XX sex reversal caused by duplication of SOX9

SOX9 is one of the genes that play critical roles in male sexual differentiation. Mutations of SOX9 leading to haploinsufficiency can cause campomelic dysplasia and XY sex reversal. We report here evidence supporting that SOX9 duplication can cause XX sex reversal. A newborn infant was referred for genetic evaluation because of abnormal male external genitalia. The infant had severe penile/scrotal hypospadias. Gonads were palpable. Cytogenetic analysis demonstrated a de novo mosaic 46,XX,dup(17)(q23.1q24.3)/46, XX karyotype. Fluorescent in situ hybridization (FISH) with a BAC clone containing the SOX9 gene demonstrated that the SOX9 gene is duplicated on the rearranged chromosome 17. The presence of SRY was ruled out by FISH with a probe containing the SRY gene and polymerase chain reaction with SRY-specific primers. Microsatellite analysis with 13 markers on 17q23-24 determined that the duplication is maternal in origin and defined the boundary of the duplication to be approximately 12 centimorgans (cM) proximal and 4 cM distal to the SOX9 gene. Thus, SOX9 duplication is the most likely cause for the sex reversal in this case because it plays an important role in male sex determination and differentiation. This study suggests that extra dose of SOX9 is sufficient to initiate testis differentiation in the absence of SRY. Other SRY-negative XX sex-reversed individuals deserve thorough investigation of SOX9 gene.     

Incomplete masculinisation of XX subjects carrying the SRY gene on an inactive X chromosome

46,XX subjects carrying the testis determining SRY gene usually have a completely male phenotype. In this study, five very rare cases of SRY carrying subjects (two XX males and three XX true hermaphrodites) with various degrees of incomplete masculinisation were analysed in order to elucidate the cause of sexual ambiguity despite the presence of the SRY gene. PCR amplification of 20 Y chromosome specific sequences showed the Yp fragment to be much longer in XX males than in true hermaphrodites. FISH analysis combined with RBG banding of metaphase chromosomes of four patients showed that in all three true hermaphrodites and in one XX male the Yp fragment was translocated onto a late replicating inactive X chromosome in over 90% of their blood lymphocytes. However, in a control classical XX male with no ambiguous features, the Yp fragment (significantly shorter than in the XX male with sexual ambiguity and only slightly longer than in XX hermaphrodites) was translocated onto the active X chromosome in over 90% of cells. These studies strongly indicate that inactivation on the X chromosome spreading into a translocated Yp fragment could be the major mechanism causing a sexually ambiguous phenotype in XX (SRY+) subjects.