Frequency and Types of Chromosomal Abnormalities in Turkish Women with Amenorrhea

Study ObjectiveTo estimate the frequency and the type of chromosomal abnormalities (CA) in patients with primary (PA) and secondary amenorrhea (SA).DesignThis retrospective study was comprised of patients had been referred to our laboratory between 1990 to 2008 and designed as original article.SettingMedical Faculty of Cukurova University in Turkey.ParticipantsChromosomal analysis was carried out on 393 patients with PA and SA that were referred to Cytogenetic laboratory of Medical Biology and Genetic Department, Faculty of Medicine, Çukurova University.InterventionsLymphocyte culturing depended karyotyping.Main Outcome MeasuresStandard lymphocyte culturing procedure and karyotyping was performed to all samples.ResultsPA and SA were identified in 393 patients. The karyotype was normal in 337 cases (85.8%) and abnormal in 56 (14.2%) patients. CAs were found in 54 (13.7%) and 2 (0.5%) of women with PA and SA, respectively. Females carrying rearrangements between autosomal and sex chromosomes were detected in 2% (8/393). The numerical abnormalities of the X chromosome were detected in 39.3% (22/56) (monosomy and mosaic). Structural abnormalities of the X and the other chromosomes were detected in 25.5% (13 of 56). Structural mosaicism of X chromosome was found in 5.4% (3 of 56). Male karyotype (46, XY) was found in 33.9% (19/56). The most frequently detected abnormality were X chromosome monosomies or mosaics.ConclusionsOur study revealed that some causes of amenorrhea could be due to CAs. Therefore, cytogenetic study should be important test in the evaluation of patients with PA or SA. The most common abnormality seen is 45,X karyotype (monosomy X/Turner Syndrome) and its variants.     

月经紊乱患者的细胞遗传学分析

目的 分析原发闭经、继发闭经及月经稀发患者的染色体核型,探讨性染色体异常对性腺发育的影响。方法 将176例患者分为两组,其中82例原发闭经组,94例继发闭经及月经稀发组。每例行外周血培养,制片及G显带,并行染色体核型分析。结果 176例患者发现性染色体异常38例,异常检出率为29.6％(38/176),其中原发闭经组33例,异常检出率为40.2％(33/82);继发闭经及月经稀发组检出性染色体异常5例,异常检出率为5.3％(5/94);两组异常检出率差异有显著性(P<0.05)。性染色体异常大体上分为三大类:含Y染色体(15例),X染色体数目异常(18例),X染色体结构异常(5例),嵌合体均以45,X系为主,共10例。结论 两条完整的染色体是女性性腺发育及正常卵巢功能所必须,性染色体异常是原发闭经的主要原因之一,常规细胞遗传学检查是必要的;继发闭经及月经稀发也不应忽视此项检查。     

Genetic abnormalities in Turkish women with premature ovarian failure

Objective

To identify the distribution of cytogenetic abnormalities among Turkish women with premature ovarian failure (POF).

Method

A karyotype analysis was performed at the Medical Genetics Department of Zekai Tahir Burak Women's Hospital, Ankara, Turkey, for 75 women younger than 40 years found to have POF over a 5-year period.

Results

There were 18 familial cases (24%), 1 of which involving an abnormality of the X chromosome [46,X,del(X)(q22)]. Sixteen patients (21.3%) had chromosomal abnormalities such as Xq and Xp deletions, translocations, and numerical aberrations; 2 had Swyer syndrome; 2 were fragile X premutation carriers; and 1 had galactosemia.

Conclusion

A genetic cause of POF was identified in 39 (52%) of 75 patients. A thorough genetic evaluation of women with POF should be performed regardless of clinical features suggestive of chromosomal abnormality.     

Novel X-chromosomal defect associated with abnormal ovarian function

Abstract Premature ovarian failure (POF) may be idiopathic or may be associated with genetic or autoimmune disorders. It is well known that chromosomal defects can impair ovarian development and its function. It is estimated that X-chromosome abnormalities occur in 10-25% of women with abnormal ovarian function. Of these, the common chromosome defects reported are either true Turner's karyotype or its variants. We describe a novel X-chromosome aberration in a woman with primary amenorrhea. Cytogenetic and fluorescence in situ hybridization analysis revealed a short-arm deletion of X-chromosome as a Turner's variant [mos,45,XO/46,Xdel(X)(p11.1-p22.3)]. This interesting and rare case with unique X-chromosome defect reveals an additional mechanism for the cause of POF.     

Screening for chromosomal abnormalities in 2650 infertile couples undergoing ICSI

Chromosomal abnormalities are the major contributor to the genetic risks of infertility treatment associated with intracytoplasmic sperm injection (ICSI). The study objective was to assess prospectively the frequency of chromosomal aberrations in couples undergoing ICSI. A total of 2650 infertile couples (5300 patients) underwent chromosome analysis before undergoing ICSI in the Egyptian IVF-ET Centre. Heparinized blood samples were cultured, harvested and banded according to standard methods. Overall, 96.94% of the patients studied (5138/5300) had a normal karyotype, while the remaining 162 patients (3.06%) had an abnormal karyotype. Male patients constituted the majority of abnormalities; 138 males (85.19%) and 24 females (14.81%). These chromosomal aberrations included 117 cases (2.2%) of sex chromosome abnormalities; 113 males and four females. Forty-five patients (0.85%) had autosomal aberrations; 25 of them were males and 20 were females. The current data show that chromosomal abnormalities affect 3.06% of infertile patients, and occur in both sexes, but more predominantly in males undergoing ICSI for male factor infertility. It is recommended that chromosomal analysis be performed before undergoing ICSI, to identify patients who can be offered preimplantation genetic diagnosis.     

Recurrent pregnancy losses and parental chromosome abnormalities: a review

Summary. A compilation of the cytogenetic results taken from 79 published surveys of couples with two or more pregnancy losses (comprising 8208 women and 7834 men) showed an overall prevalence of major chromosome abnormalities of 2.9%. This is five to six times higher than that of the general adult population. In every group of chromosome abnormalities in the parents a predominance of female to male affected was noted (2:1). Approximately 50% of all chromosome abnormalities detected were balanced reciprocal translocations, 24% were Robertsonian translocations, 12% were sex chromosomal mosaicisms in females, and the rest consisted of inversions and other sporadic abnormalities. Parents with two or more idiopathic pregnancy losses should be karyotyped to aid in management and counselling. When a translocation or other abnormality (e.g. X chromosomal mosaicism) predisposing to an abnormal zygote is found, prenatal diagnosis is indicated in future pregnancies. Even when parental karyotypes are normal, prenatal diagnosis should be considered in subsequent pregnancies of parents with two or more pregnancy losses because of the high incidence of chromosome abnormalities in spontaneous abortions. For the same reason, if a single previous pregnancy loss is known to have been chromosomally aneuploid, parental karyotypes may have to be examined (depending upon the finding in the pregnancy loss), and prenatal diagnosis should also be considered in subsequent pregnancies.     

Recurrent pregnancy losses and parental chromosome abnormalities: a review

A compilation of the cytogenetic results taken from 79 published surveys of couples with two or more pregnancy losses (comprising 8208 women and 7834 men) showed an overall prevalence of major chromosome abnormalities of 2.9%. This is five to six times higher than that of the general adult population. In every group of chromosome abnormalities in the parents a predominance of female to male affected was noted (2:1). Approximately 50% of all chromosome abnormalities detected were balanced reciprocal translocations, 24% were Robertsonian translocations, 12% were sex chromosomal mosaicisms in females, and the rest consisted of inversions and other sporadic abnormalities. Parents with two or more idiopathic pregnancy losses should be karyotyped to aid in management and counselling. When a translocation or other abnormality (e.g. X chromosomal mosaicism) predisposing to an abnormal zygote is found, prenatal diagnosis is indicated in future pregnancies. Even when parental karyotypes are normal, prenatal diagnosis should be considered in subsequent pregnancies of parents with two or more pregnancy losses because of the high incidence of chromosome abnormalities in spontaneous abortions. For the same reason, if a single previous pregnancy loss is known to have been chromosomally aneuploid, parental karyotypes may have to be examined (depending upon the finding in the pregnancy loss), and prenatal diagnosis should also be considered in subsequent pregnancies.     

Prenatal cytogenetic diagnosis in amniocentesis.

From 1982 to 1990, cytogenetic studies were successfully conducted in 2,975 (96.19%) of the 3,096 pregnant women who underwent amniocentesis. The average maternal age was 33.7 years and the average gestational age was 18.1 weeks. Common indications of amniocentesis included advanced maternal age (AMA) (54.76%), previous fetus with chromosomal aberrations (6.82%) or gross anomalies (5.01%), intrauterine gross anomaly (4.97%) and maternal exposure to drugs or radiation (5.28%). Among the 89 cases (2.99%) with detected chromosomal aberrations, 53 were numeric (31 trisomies, 21 sex chromosome aberrations and one tripoidy) and 36 were structural (six de novo and 30 hereditary structural rearrangement). The incidence of chromosomal aberrations was 2.03% in cases with AMA. While only four of the 143 cases with previous fetal trisomy 21 had recurrence, the recurrent rate was 90.91% in 11 cases with previous fetal chromosomal translocation. Thirty (20.27%) of the 148 cases with abnormal sonograms showed chromosomal aberrations. Certain congenital anomalies are closely associated with cytogenetic changes: duodenal atresia and trisomy 21; cystic hygroma and 45,X; and polyhydramnios and trisomy 18. Only two of the 157 cases with indications of drug or radiation exposure had abnormal cytogenetic studies. Two of the 53 cases with detected numerical aberrations (47,XXY and 47,XXX) and 27 cases with hereditary structural rearrangement elected to continue their pregnancies. All of these babies were delivered without gross anomalies. This study suggests that for prenatal diagnosis. However, complementary measures, such as routine antenatal ultrasound and maternal serum alphafetoprotein, should be added to increase the efficacy of genetic amniocentesis.     

Does the number of previous miscarriages influence the incidence of chromosomal aberrations in spontaneous pregnancy loss?

Objective: Chromosomal aberrations are a common cause for miscarriage. The purpose of this study was to evaluate factors that influence the frequency of chromosomal abnormalities in miscarriages and provide clinicians with a guideline for management of such cases.

Methods: The study included 170 women who experienced pregnancy loss between the 2004 and 2014. Cytogenetic analysis of products of conception (POC) was routinely performed.

Results: Successful cytogenetic analysis was achieved in 144 cases (84%). Of these, 78 cases (54%) had a chromosomal aberration. The incidence of chromosomal aberrations was not statistically significant among patients with 1, 2, 3, 4 or?≥5 previous miscarriages (33.3%, 57.4%, 48.6%, 65.2%, and 59.1%, respectively, p?=?0.227). The F/M ratio was similar in normal and abnormal POC karyotypes (1.2:1 and 1.3:1, respectively, p?=?0.7).

Conclusion: Contrary to previous assumptions we did not find correlation between number of previous spontaneous miscarriages a women experienced and chromosomal aberration in her current miscarriage.     

Evaluation of 1100 couples with recurrent pregnancy loss using conventional cytogenetic,PGD, and PGS: hype or hope

Recurrent pregnancy loss (RPL) is an important clinical problem, mostly resulting from chromosomal or genetic defects, while in 30–60% of cases, it is idiopathic. The aim of this study is to evaluate the frequency and types of chromosomal abnormalities, also pre-implantation genetic diagnosis (PGD) and pre-implantation genetic screening (PGS) outcomes among Iranian couples with RPL. This retrospective study was conducted on 1100 Iranian couples (2200 individuals) with RPL referred to Royan Institute between 2008 and 2014. Karyotyping had been performed using standard cytogenetic techniques. PGD results of RPL patients with abnormal karyotypes and PGS results of RPL patients with normal karyotypes were also analyzed. The frequency of chromosomal abnormalities in these patients was 4.95%. Women demonstrated more abnormalities (6.82%) in comparison to men (3.09%). The successful rate of pregnancy after PGD and PGS was 52 and 18.64%, respectively. The observation of 4.95% chromosomal abnormalities among the patients with RPL could support this hypothesis that there is a direct relationship between chromosomal abnormalities and RPL. More than half of the patients who underwent PGD had successful pregnancy; therefore, this approach can improve the success rate of pregnancy in them. The results of PGS cycles showed that this technique could increase the live birth rate in RPL patients.     

无精子症及少弱精子症2436例患者的细胞遗传学病因分析

目的:探讨无精子症、少弱精子症患者外周血染色体核型与男性精液异常的关系,为不育症的诊断和治疗提供临床理论依据。方法:对2010年至2015年在华中科技大学同济医学院附属同济医院妇产科门诊就诊的无精子症及少弱精子症患者进行外周血染色体核型分析(G显带)。结果:2436例患者中染色体核型异常者340例(13.96%),其中性染色体异常208例(61.18%),以克氏综合征最常见;常染色体异常132例(38.82%),以常染色体多态性、易位最为常见。1014例无精子症患者染色体核型异常179例(17.65%),主要表现为性染色体数目异常(81例,45.25%);1422例少弱精子症患者染色体核型异常161例(11.32%),主要表现为性染色体(69例,42.86%)、常染色体(84例,52.17%)结构异常。无精子症与少弱精子症患者染色体异常的构成类型不同,差异有统计学意义(P0.05)。结论:无精子症或少弱精子症的形成与染色体异常的类型密切相关,细胞遗传学分析对于明确不育症病因及指导进一步治疗有重要意义。     

产前诊断指征在胎儿染色体异常诊断中的价值探讨

目的:探讨产前诊断指征在胎儿染色体异常诊断中的价值及其对妊娠结局的指导意义.方法:对439例有产前诊断指征的孕妇,在超声引导下经腹羊膜腔穿刺抽取羊水检查染色体核型,比较不同产前诊断指征的胎儿染色体异常检出率,分析各组染色体异常类型与妊娠结局的关系.结果:①胎儿染色体异常检出15例,总的异常检出率3.42%.夫妇平衡易位组胎儿染色体异常检出率最高为66.67%,与高龄组、唐氏高危组、不良孕产史(夫妇染色体检查正常)组比较,差异有统计学意义(P<0.05);而高龄组、唐氏高危组、不良孕产史组和超声检查异常组的胎儿染色体异常检出率分别为5.22%、2.28%、1.54%、16.67%、,组间两两比较差异均无统计学意义(P>0.05).②15例染色体异常中.高龄组占40.00%,唐氏高危组占33.33%.染色体数目异常6例,5例行孕中期引产;结构异常7例,1例行孕中期引产,1例流产;嵌合体2例均行孕中期引产;余6例足月分娩.结论:对具有产前诊断指征的孕妇进行羊水细胞培养及染色体核型分析,不仅能及时发现胎儿染色体异常,为孕妇是否继续妊娠提供科学依据,而且有利于降低出生缺陷发生率.     

2178对自然流产史夫妇染色体分析

目的:分析自然流产史夫妇外周血染色体异常核型的种类及其在男女性中的分布特点。方法:检测2178对自然流产史夫妇外周血淋巴细胞染色体核型,分析比较染色体变异的种类、发生率及其在男、女性中的分布差异。结果:2178对(4356例)自然流产史夫妇中发现染色体异常539例(12.37%),其中男266例,女273例。染色体结构异常87例,其中相互易位最多见为58例(66.7%,58/87),有27例为世界首报染色体结构异常核型。其次为罗伯逊易位13例,倒位6例,插入、缺失等其他异常核型10例。染色体数目异常8例,包括2例标记染色体、1例XYY及5例不同类型的X染色体非整倍体嵌合。多态性改变444例中,D/G组染色体随体区变异最为多见,共271例(61.04%,271/444)。结论:自然流产史夫妇外周血染色体异常均有发生,男女性发生率并无明显差异,染色体异常以相互易位为主。染色体多态性发生率较高,对以自然流产史就诊的夫妇,有必要同时进行染色体检查,有助于病因的分析与诊断,并为临床咨询及后续生殖干预提供依据。     

Premature ovarian failure and fragile X premutation: a study on 45 women

OBJECTIVE: The aim of this study was to test for the presence of the fragile X (FRAXA) premutation a group of women with early menopause. STUDY DESIGN: 45 women with idiopathic premature ovarian failure (POF), five with a familial and 40 with a sporadic form, were screened for the presence of FRAXA premutation. A control group of 28 women >45 years, with one or more children and no signs of POF, was also studied. RESULTS: We found three cases of fragile X premutations in women all belonging to the group with sporadic POF. CONCLUSION: Our results seems to confirm previous observations on the non random association between POF and FRAXA premutation.     

Ovulation induction in a woman with premature ovarian failure resulting from a partial deletion of the X chromosome long arm, 46,X,del(X)(q22)

Objective: To report successful ovulation induction in a woman with premature ovarian failure (POF) resulting from a partial Xq deletion.Design: An uncontrolled study. Setting: University hospital.Patient(s): A 27-year-old woman with 46,X,del(X)(q22) who had hypergonadotropic secondary amenorrhea.Intervention(s): Injections of hMG (225 IU/d) for 8 consecutive days after endogenous gonadotropin suppression with a long-acting GnRH agonist (900 μg/d) for 12 weeks, together with cyclic sex steroid replacement therapy.Main Outcome Measures: Serum concentrations of E₂ and P as well as ultrasonography.Result(s): Folliculogenesis and ovulation.Conclusion(s): Ovulation induction is possible in patients with POF caused by X chromosome aberrations.     

Results of preimplantation genetic diagnosis in patients with Klinefelter's syndrome

With the application of preimplantation genetic diagnosis (PGD), a possible genetic contribution of spermatozoa obtained from 47,XXY non-mosaic Klinefelter patients on preimplantation embryos was analysed in eight couples. Interpretable fluorescence in-situ hybridization results were obtained for 28 out of 33 embryos biopsied (84.8%) and 23 blastomeres were analysed for chromosomes 13, 18, 21, X and Y. Nine out of 23 embryos were diagnosed as abnormal (39.1%). Five out of nine contained sex chromosome abnormalities (55.5%). Two were diagnosed as 47,XXY and three were found to have monosomy X. Besides sex chromosomal abnormalities, other abnormalities detected were haploidy, triploidy, monosomy 13, monosomy 18 and trisomy 13. Five blastomeres were analysed for sex chromosomes only and all of them were found to be normal. Overall, the rate of sex chromosome abnormality in biopsied embryos was found to be 17.8% (5/28). Moreover, among 33 embryos biopsied, five of the eight zygotes, which were classified as a poor prognosis group according to pronuclear morphology scoring, showed an impaired growth profile after biopsy and were found to be chromosomally abnormal. Elimination of abnormal embyos and transfer of normal ones resulted in four pregnancies in eight cycles (50%). Two pregnancies, one singleton and one twins resulted in healthy births. Two pregnancies, one singleton and one twins are continuing beyond the second trimester. These results show that there is in fact elevated chromosomal abnormality for both sex chromosomes and autosomes in embryos developed from Klinefelter males. Furthermore together with PGD, embryo scoring according to pronuclear morphology can give additional benefit for selecting chromosomally abnormal embryos. Therefore, PGD should be recommended in cases with Klinefelter's syndrome and this information should be discussed with the couple when genetic counselling is given.     

Chromosomal deletions detected at amniocentesis

ObjectiveThe aim of this study is to present the incidence, prenatal and postnatal findings, and modes of ascertainment in chromosomal deletions detected at amniocentesis.Materials and methodsWe reviewed all the cases with chromosomal deletions, which were detected by amniocentesis in Mackay Memorial Hospital, Taipei, Taiwan, between January 1987 and December 2012. Data on the locations and types of deletion, reasons for performing amniocentesis, maternal age, gestational age at amniocentesis, fetal karyotypes, inheritance of deletions, and relative prenatal findings were collected.ResultsAmniocentesis was performed in 33,305 cases within this period of time. Among these, 31 cases of chromosomal deletions were considered for the study. The mean gestational age at amniocentesis was 21.0 weeks (range from 15 weeks to 32 weeks) and the mean maternal age at amniocentesis was 32.1 years (range from 26 years to 37 years). Nineteen cases (61.3%) manifested fetal structural abnormalities on ultrasound, nine (29.0%) presented no ultrasound abnormalities, and three had an unknown status. The main modes of ascertainment included abnormal ultrasound findings in 10 cases (32.2%), advanced maternal age in 11 cases (35.5%), abnormal maternal serum screening results in six cases (19.6%), and other reasons in four cases (13.0%). Of the 27 cases with known inheritance, the deletion was inherited in two (6.6%) and de novo in 25 (92.6%). Males accounted for 11 (35.5%) and females for 20 (64.5%) cases. Chromosomal deletions are more often to occur in chromosomal 5(4 cases, 12.9%), chromosomal 18 (4 cases, 12.9%), chromosomal 4 (3 cases, 9.7%), chromosomal 7 (3 cases, 9.7%), chromosomal 10 (3 cases, 9.7%), chromosomal 11 (3 cases, 9.7%), and chromosomal 1 (2 cases, 6.5%). There were four cases of chromosomal mosaicism: two involved chromosome 5, one involved chromosome 10, and one involved chromosome 18. Twenty-three cases (74.2%) had terminal deletions and the other eight cases (26.7%) had interstitial-type deletions.ConclusionIn summary, we have presented the results of prenatal diagnosis for chromosomal deletions using amniocentesis. Chromosomal deletions are more likely to occur in females and more often in chromosomal 5p and 18q. Prenatal diagnosis at amniocentesis is frequently associated with advanced maternal age, abnormal ultrasound findings, and abnormal maternal serum screening. The frequency of ascertainment in chromosome deletion seems to be directly correlated with advanced maternal age and abnormal ultrasound findings. In cases with terminal deletions, prenatal ultrasound plays a more important role for prenatal diagnosis.     

Chromosomal abnormalities in men with pregestational and gestational infertility in northeast China

Purpose

To detect incidences and the types of chromosomal abnormalities in Chinese men with infertility and determine chromosomal factors association with various phenotypes.

Methods

Semen analysis and karyotype analysis by G-banding were carried out in 4,659 idiopathic infertile males; additionally, multiplex PCR using nine specific sequence-tagged sites (STSs) was used to detect azoospermia factor (AZF) microdeletions in 412 patients with Y chromosomal abnormalities.

Results

Male infertility was divided into pregestational infertility, characterized by failure to produce a fertilized ovum, and gestational infertility, characterized by embryo loss after fertilization. The former can result from azoospermia, oligozoospermia or oligoasthenozoospermia syndrome, while the latter is associated with developmental early pregnancy loss, habitual miscarriage and stillbirth. Among 4,659 male patients, 412 (8.84 %) showed abnormal chromosomal karyotypes, including 314 (6.74 %) with sex chromosomal abnormalities and 98 (2.10 %) with autosomal abnormalities. The prevalences of numerical and structural abnormalities among patients with chromosomal abnormalities were 259/412 (62.86 %) and 153/412 (37.14 %), respectively. Furthermore, structural sex chromosomal abnormalities were represented by various phenotypic profiles (46,XX, 47,XYY and 45,X/46,XY), and a prevalence of AZF microdeletions of 19/79 (24.05 %). AZF microdeletions were highly associated with Y chromosomal abnormalities (P = 0.018).

Conclusion

Various chromosomal abnormalities that result in male infertility could affect spermatogenesis or embryonic development at different levels. Sex chromosomal and autosomal abnormalities were highly associated with pregestational and gestational infertility, respectively. AZF microdeletions may play an important role in lowering the stability of the Y chromosome.     

Effectiveness of prenatal chromosomal analysis using multicolor fluorescent in situ hybridisation

Objective To evaluate the clinical effectiveness of multicolour fluorescent in situ hybridisation (FISH) analysis in routine prenatal diagnosis.
Design Prospective study.
Sample 3203 amniotic fluid samples.
Methods Unique DNA (chromosomes 13 and 21) and α satellite centromeric-specific (chromosomes X, Y and 18) probes were used in two mixes to permit the simultaneous analysis of several chromosomes. The performance of multicolour FISH and conventional cytogenetic analysis was compared.
Results Conventional cytogenetic analysis identified 111 chromosomal abnormalities, of which 94 were potentially detectable by the FISH technique and 97 would be typically associated with neonatal phenotypic abnormalities. Multicolour FISH analysis detected 84% (93/111) of all chromosome abnormalities and 99% (93/94) of abnormalities where there was a specific probe. The sensitivity of multicolour FISH analysis was 95% (92/97) for chromosomal abnormalities likely to result in an abnormal postnatal outcome. Multiple ultrasound abnormalities were detected in all five cases of clinically relevant chromosomal abnormalities missed by multicolour FISH. FISH results were available within 48 hours and the sample failure rate was 0.1% (3/3202).
Conclusion Multicolour FISH analysis is a sensitive and reliable technique for the rapid prenatal diagnosis of chromosomal abnormalities. Examining only five chromosomes allowed 95% of clinically relevant chromosomal abnormalities to be diagnosed correctly. As routine antenatal screening is targeted at the major autosomal trisomies and sex chromosome aneuploidies, multicolour FISH analysis may potentially replace conventional cytogenetic analysis in routine prenatal diagnosis.     

无创产前基因检测在胎儿性染色体疾病筛查中的应用

目的探讨无创产前基因检测(non-invasive prenatal genetic testing,NIPT)在胎儿性染色体疾病中的临床价值。方法统计深圳市第二人民医院2016年3月至2019年6月行NIPT的16119例单胎孕妇中提示21-三体、18-三体、13-三体、性染色体异常和其他染色体异常的阳性率;对比2016年3月至2019年6月NIPT示“胎儿性染色体异常”与本院染色体核型结果。结果①NIPT对21-三体,18-三体,13-三体,性染色体异常和其他染色体异常筛查的阳性率分别为0.42%(68/16119),0.10%(16/16119),0.07%(11/16119),0.38%(61/16119)和0.22%(36/16119)。②47例“NIPT示胎儿性染色体异常”者中,确诊为性染色体疾病者26例,阳性预测值55.32%。其中,NIPT对胎儿性染色体数目偏多的阳性预测值为91.30%(21/23),对胎儿性染色体数目偏少的阳性预测值20.0%(4/20),对胎儿性染色体数目异常的阳性预测值25.0%(1/4)。结论NIPT可作为胎儿性染色体疾病的筛查方法,但由于其对性染色体偏少和性染色体数目异常的假阳性率较高,检测阳性者仍需要做侵入性产前诊断确诊。