Chromosomal factors of infertility in candidate couples for ICSI: an equal risk of constitutional aberrations in women and men

To assess the frequency of chromosomal aberrations in French candidates for intracytoplasmic sperm injection (ICSI), and to explore the existence of a female chromosomal factor in some cases of couple infertility, a collaborative retrospective clinical and cytogenetic study was performed, launched by the Association des Cytogénéticiens de Langue Franciaise (ACLF). The karyotypes of 3208 patients [2196 men (68.4%), 1012 (31.6%) women] included in ICSI programmes over a 3-year period in France were collected. A total of 183 aberrant karyotypes was diagnosed, corresponding to an abnormality frequency of 6.1% (134/2196) for men and 4.84% (49/1012) for women. The following frequencies of abnormalities were observed respectively for men and women: 1.23% (n = 27) and 0.69% (n = 7) for reciprocal translocations, 0.82% (n = 18) and 0.69% (n = 7) for Robertsonian translocations, 0.13% (n = 3) and 0.69% (n = 7) for inversions, 3.32% (n = 73) and 2.77% (n = 28) for numerical sex chromosome aberrations, and 0.59% (n = 13) and 0% for other structural aberrations. Among the male patients of this latter group, 0.40% (n = 9) had a Y chromosome abnormality. Among the male patients with numerical sex chromosome abnormalities, 2.23% (n = 49) were 47,XXY, 0.32% (n = 7) were 47,XYY, and 0.77% (n = 17) had a mosaicism for numerical sex chromosome anomalies. All the female patients with sex chromosome abnormalities (2.77%, n = 28) had mosaicism for numerical sex chromosome anomalies. Even if these cases-the significance of which was sometimes questioned-were disregarded in the analysis, 2.08% (21/1012) of abnormal karyotypes remained in women. An overall increased frequency of chromosomal aberrations was found, and this confirmed that in some cases of poor reproductive outcome there may be a contribution of maternal chromosome aberrations. Indeed, the existence of a chromosome abnormality in the female partner was associated with the group of infertile men in which there was no apparent cause of infertility.     

Type and frequency of chromosome aberrations in 781 couples undergoing intracytoplasmic sperm injection.

Cytogenetic investigations were performed in 781 couples prior to intracytoplasmic sperm injection (ICSI) because of severe male infertility or fertilization failures in previous in-vitro fertilization attempts. Out of these 1562 patients, 1012 had a normal karyotype without any aberrations (64.8%), 204 patients had an abnormal karyotypes (13.1%). These chromosome aberrations included constitutional aberrations (4.4%), fragile sites of autosomes (3.0%), low level mosaicism of sex chromosomes (4.0%) and secondary structural chromosome aberrations (4.2%). Combinations of different types of abnormalities were stated. Another 346 patients (22.1%) showed single cell aberrations; the significance of these is unclear at the moment. Constitutional chromosome aberrations were detected in 69 patients. The following chromosome aberrations were observed: 35 sex chromosomal aberrations (comprising hyperploidies of X or Y chromosomes, mosaicisms and derivative X and Y chromosomes), 34 autosomal aberrations including 14 reciprocal translocations, five Robertsonian translocations, six inversions, one marker chromosome, one trisomy 18 mosaicism and seven other structural aberrations. Three autosomal regions showed fragile sites: 6q13 in 2.9% of the patients, 17p12 and 10q24 in 0.05% each. In conclusion, our data show that a high number of infertile couples in an ICSI programme are affected by chromosome aberrations which occur in both sexes. It is suggested that a chromosomal analysis should be performed on both partners before ICSI treatment is initiated.     

Relevance of genetic counselling in couples prior to intracytoplasmic sperm injection

Since the first reports of successful pregnancies after treatment with intracytoplasmic sperm injection (ICSI) in humans numerous attempts have been made to assess the genetic risks of this highly invasive technique. During the study period (February 1995-November 96), 142 couples were referred to our genetic counselling unit prior to ICSI. In three couples, genetic counselling revealed a high recurrence risk for a monogenic disease (myotonic dystrophy, hereditary ataxia and polycystic kidney disease). In nine out of 128 men (7%) an abnormal karyotype was identified, including three Robertsonian translocations, two reciprocal translocations, three sex chromosome aberrations and one case with centric fission of chromosome no. 7. A total of 14 men refused chromosomal analysis. Only one of the 122 women examined had an abnormal karyotype (47, XXX). Five out of six men with congenital bilateral absence of the vas deferens (CBAVD) had at least one mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Three had mutations in both CFTR alleles, including one case in which the second mutation was the 5T allele. One patient with CBAVD and a single Delta F508 CFTR mutation also had left renal agenesis. In conclusion, we strongly recommend that genetic counselling, chromosomal analysis and, in the case of CBAVD, screening for CFTR mutations should be offered to all couples with a diagnosis of male or idiopathic infertility.      

A Danish national cohort of 730 infants born after intracytoplasmic sperm injection (ICSI) 1994-1997.

This national cohort study included all clinical pregnancies obtained after intracytoplasmic sperm injection (ICSI) registered in Denmark between January 1994 and July 1997 at five public and eight private fertility clinics. Laboratory and clinical data were obtained from the fertility clinics. The couples answered a questionnaire regarding the pregnancy and the health of the child (response rate 94%). Data validation was carried out through discharge charts. The mean age of the women was 32.1 years. In 84.2% of couples, male factor was the main reason for performing ICSI, and in 4.8% epididymal spermatozoa were used. The mean number of embryos replaced was 2.3 (range 1-3) and in 95% of cases fresh embryos were transferred. Only 183 women (28.5%) underwent prenatal diagnosis, resulting in 209 karyotypes with seven (3.3%) chromosome aberrations. Six major chromosomal abnormalities (2.9%) and one inherited structural chromosome aberration (0.5%) were found, but no sex chromosome aberrations. The frequency of multiple birth, Caesarean section rate, gestational age, preterm birth, and birth weight were comparable with previous studies. The perinatal mortality rate was 13.7 per 1000 children born with a gestational age of 24 weeks or more. In 2.2% (n = 16) of the liveborn infants, and in 2.7% (n = 20) of all infants, major birth defects were reported by the parents. Minor birth defects were found in nine liveborn infants (1.2%). In conclusion, the results of this study on outcome of ICSI pregnancies are in line with earlier reports, except that no sex chromosome abnormalities were found.     

Genetic risk factors in infertile men with severe oligozoospermia and azoospermia.

BACKGROUND: Male infertility due to severe oligozoospermia and azoospermia has been associated with a number of genetic risk factors. METHODS: In this study 150 men from couples requesting ICSI were investigated for genetic abnormalities, such as constitutive chromosome abnormalities, microdeletions of the Y chromosome (AZF region) and mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. RESULTS: Genetic analysis identified 16/150 (10.6%) abnormal karyotypes, 8/150 (5.3%) AZFc deletions and 14/150 (9.3%) CFTR gene mutations. An abnormal karyotype was found both in men with oligozoospermia and azoospermia: 9 men had a sex-chromosomal aneuploidy, 6 translocations were identified and one marker chromosome was found. Y chromosomal microdeletions were mainly associated with male infertility, due to testicular insufficiency. All deletions identified comprised the AZFc region, containing the Deleted in Azoospermia (DAZ) gene. CFTR gene mutations were commonly seen in men with congenital absence of the vas deferens, but also in 16% of men with azoospermia without any apparent abnormality of the vas deferens. CONCLUSIONS: A genetic abnormality was identified in 36/150 (24%) men with extreme oligozoospermia and azoospermia. Application of ICSI in these couples can result in offspring with an enhanced risk of unbalanced chromosome complement, male infertility due to the transmission of a Y-chromosomal microdeletion, and cystic fibrosis if both partners are CFTR gene mutation carriers. Genetic testing and counselling is clearly indicated for these couples before ICSI is considered.     

中国东北地区人群中不良孕产夫妇的细胞遗传学分析

目的 观察染色体异常在中国东北地区不良孕产夫妇中的分布类型及其与不良孕产的关系.方法 对来自辽宁省生殖健康重点实验室的2158对不良孕产夫妇进行细胞遗传学分析,普通G显带方法分析细胞核型,必要时采用C或R显带方法.结果 在2158对不良孕产夫妇中发现染色体异常137例,异常率为3.17%.其中数目异常3例,结构畸变134例.结构畸变中分别为相互易位90例,罗迫逊易位34例,倒位9例,缺失1例,经中国医学细胞遗传学国家培训中心(湖南)鉴定,43例为国内外首次报道.染色体异态378例,异态率8.76%.结论 在中国不良孕产夫妇中发生的染色体异常主要是染色体结构畸变,异常类型复杂、多样,其中染色体相互易位和罗迫逊易位所占比例最大,并呈现出随着流产次数的增加染色体异常率也增加的趋势.同时,染色体异态在不良孕产夫妇中发生率较高.细胞遗传学分析是不良孕产夫妇病因诊断的一个重要指标.     

中国东北地区人群中不良孕产夫妇的细胞遗传学分析

目的 观察染色体异常在中国东北地区不良孕产夫妇中的分布类型及其与不良孕产的关系.方法 对来自辽宁省生殖健康重点实验室的2158对不良孕产夫妇进行细胞遗传学分析,普通G显带方法分析细胞核型,必要时采用C或R显带方法.结果 在2158对不良孕产夫妇中发现染色体异常137例,异常率为3.17%.其中数目异常3例,结构畸变134例.结构畸变中分别为相互易位90例,罗迫逊易位34例,倒位9例,缺失1例,经中国医学细胞遗传学国家培训中心(湖南)鉴定,43例为国内外首次报道.染色体异态378例,异态率8.76%.结论 在中国不良孕产夫妇中发生的染色体异常主要是染色体结构畸变,异常类型复杂、多样,其中染色体相互易位和罗迫逊易位所占比例最大,并呈现出随着流产次数的增加染色体异常率也增加的趋势.同时,染色体异态在不良孕产夫妇中发生率较高.细胞遗传学分析是不良孕产夫妇病因诊断的一个重要指标.     

中国东北地区人群中不良孕产夫妇的细胞遗传学分析

目的 观察染色体异常在中国东北地区不良孕产夫妇中的分布类型及其与不良孕产的关系.方法 对来自辽宁省生殖健康重点实验室的2158对不良孕产夫妇进行细胞遗传学分析,普通G显带方法分析细胞核型,必要时采用C或R显带方法.结果 在2158对不良孕产夫妇中发现染色体异常137例,异常率为3.17%.其中数目异常3例,结构畸变134例.结构畸变中分别为相互易位90例,罗迫逊易位34例,倒位9例,缺失1例,经中国医学细胞遗传学国家培训中心(湖南)鉴定,43例为国内外首次报道.染色体异态378例,异态率8.76%.结论 在中国不良孕产夫妇中发生的染色体异常主要是染色体结构畸变,异常类型复杂、多样,其中染色体相互易位和罗迫逊易位所占比例最大,并呈现出随着流产次数的增加染色体异常率也增加的趋势.同时,染色体异态在不良孕产夫妇中发生率较高.细胞遗传学分析是不良孕产夫妇病因诊断的一个重要指标.     

中国东北地区人群中不良孕产夫妇的细胞遗传学分析

目的 观察染色体异常在中国东北地区不良孕产夫妇中的分布类型及其与不良孕产的关系。方法 对来自辽宁省生殖健康重点实验室的2158对不良孕产夫妇进行细胞遗传学分析，普通G显带方法分析细胞核型，必要时采用C或R显带方法。结果 在2158对不良孕产夫妇中发现染色体异常137例，异常率为3.17%。其中数目异常3例，结构畸变134例。结构畸变中分别为相互易位90例，罗伯逊易位34例，倒位9例，缺失1例，经中国医学细胞遗传学国家培训中心（湖南）鉴定，43例为国内外首次报道。染色体异态378例，异态率8.76%。结论 在中国不良孕产夫妇中发生的染色体异常主要是染色体结构畸变，异常类型复杂、多样，其中染色体相互易位和罗伯逊易位所占比例最大，并呈现出随着流产次数的增加染色体异常率也增加的趋势。同时，染色体异态在不良孕产夫妇中发生率较高。细胞遗传学分析是不良孕产夫妇病因诊断的一个重要指标。     

中国东北地区人群中不良孕产夫妇的细胞遗传学分析

目的 观察染色体异常在中国东北地区不良孕产夫妇中的分布类型及其与不良孕产的关系.方法 对来自辽宁省生殖健康重点实验室的2158对不良孕产夫妇进行细胞遗传学分析,普通G显带方法分析细胞核型,必要时采用C或R显带方法.结果 在2158对不良孕产夫妇中发现染色体异常137例,异常率为3.17%.其中数目异常3例,结构畸变134例.结构畸变中分别为相互易位90例,罗迫逊易位34例,倒位9例,缺失1例,经中国医学细胞遗传学国家培训中心(湖南)鉴定,43例为国内外首次报道.染色体异态378例,异态率8.76%.结论 在中国不良孕产夫妇中发生的染色体异常主要是染色体结构畸变,异常类型复杂、多样,其中染色体相互易位和罗迫逊易位所占比例最大,并呈现出随着流产次数的增加染色体异常率也增加的趋势.同时,染色体异态在不良孕产夫妇中发生率较高.细胞遗传学分析是不良孕产夫妇病因诊断的一个重要指标.     

中国东北地区人群中不良孕产夫妇的细胞遗传学分析

目的 观察染色体异常在中国东北地区不良孕产夫妇中的分布类型及其与不良孕产的关系.方法 对来自辽宁省生殖健康重点实验室的2158对不良孕产夫妇进行细胞遗传学分析,普通G显带方法分析细胞核型,必要时采用C或R显带方法.结果 在2158对不良孕产夫妇中发现染色体异常137例,异常率为3.17%.其中数目异常3例,结构畸变134例.结构畸变中分别为相互易位90例,罗迫逊易位34例,倒位9例,缺失1例,经中国医学细胞遗传学国家培训中心(湖南)鉴定,43例为国内外首次报道.染色体异态378例,异态率8.76%.结论 在中国不良孕产夫妇中发生的染色体异常主要是染色体结构畸变,异常类型复杂、多样,其中染色体相互易位和罗迫逊易位所占比例最大,并呈现出随着流产次数的增加染色体异常率也增加的趋势.同时,染色体异态在不良孕产夫妇中发生率较高.细胞遗传学分析是不良孕产夫妇病因诊断的一个重要指标.     

中国东北地区人群中不良孕产夫妇的细胞遗传学分析

目的 观察染色体异常在中国东北地区不良孕产夫妇中的分布类型及其与不良孕产的关系.方法 对来自辽宁省生殖健康重点实验室的2158对不良孕产夫妇进行细胞遗传学分析,普通G显带方法分析细胞核型,必要时采用C或R显带方法.结果 在2158对不良孕产夫妇中发现染色体异常137例,异常率为3.17%.其中数目异常3例,结构畸变134例.结构畸变中分别为相互易位90例,罗迫逊易位34例,倒位9例,缺失1例,经中国医学细胞遗传学国家培训中心(湖南)鉴定,43例为国内外首次报道.染色体异态378例,异态率8.76%.结论 在中国不良孕产夫妇中发生的染色体异常主要是染色体结构畸变,异常类型复杂、多样,其中染色体相互易位和罗迫逊易位所占比例最大,并呈现出随着流产次数的增加染色体异常率也增加的趋势.同时,染色体异态在不良孕产夫妇中发生率较高.细胞遗传学分析是不良孕产夫妇病因诊断的一个重要指标.     

中国东北地区人群中不良孕产夫妇的细胞遗传学分析

目的 观察染色体异常在中国东北地区不良孕产夫妇中的分布类型及其与不良孕产的关系.方法 对来自辽宁省生殖健康重点实验室的2158对不良孕产夫妇进行细胞遗传学分析,普通G显带方法分析细胞核型,必要时采用C或R显带方法.结果 在2158对不良孕产夫妇中发现染色体异常137例,异常率为3.17%.其中数目异常3例,结构畸变134例.结构畸变中分别为相互易位90例,罗迫逊易位34例,倒位9例,缺失1例,经中国医学细胞遗传学国家培训中心(湖南)鉴定,43例为国内外首次报道.染色体异态378例,异态率8.76%.结论 在中国不良孕产夫妇中发生的染色体异常主要是染色体结构畸变,异常类型复杂、多样,其中染色体相互易位和罗迫逊易位所占比例最大,并呈现出随着流产次数的增加染色体异常率也增加的趋势.同时,染色体异态在不良孕产夫妇中发生率较高.细胞遗传学分析是不良孕产夫妇病因诊断的一个重要指标.     

中国东北地区人群中不良孕产夫妇的细胞遗传学分析

目的 观察染色体异常在中国东北地区不良孕产夫妇中的分布类型及其与不良孕产的关系.方法 对来自辽宁省生殖健康重点实验室的2158对不良孕产夫妇进行细胞遗传学分析,普通G显带方法分析细胞核型,必要时采用C或R显带方法.结果 在2158对不良孕产夫妇中发现染色体异常137例,异常率为3.17%.其中数目异常3例,结构畸变134例.结构畸变中分别为相互易位90例,罗迫逊易位34例,倒位9例,缺失1例,经中国医学细胞遗传学国家培训中心(湖南)鉴定,43例为国内外首次报道.染色体异态378例,异态率8.76%.结论 在中国不良孕产夫妇中发生的染色体异常主要是染色体结构畸变,异常类型复杂、多样,其中染色体相互易位和罗迫逊易位所占比例最大,并呈现出随着流产次数的增加染色体异常率也增加的趋势.同时,染色体异态在不良孕产夫妇中发生率较高.细胞遗传学分析是不良孕产夫妇病因诊断的一个重要指标.     

中国东北地区人群中不良孕产夫妇的细胞遗传学分析

目的 观察染色体异常在中国东北地区不良孕产夫妇中的分布类型及其与不良孕产的关系.方法 对来自辽宁省生殖健康重点实验室的2158对不良孕产夫妇进行细胞遗传学分析,普通G显带方法分析细胞核型,必要时采用C或R显带方法.结果 在2158对不良孕产夫妇中发现染色体异常137例,异常率为3.17%.其中数目异常3例,结构畸变134例.结构畸变中分别为相互易位90例,罗迫逊易位34例,倒位9例,缺失1例,经中国医学细胞遗传学国家培训中心(湖南)鉴定,43例为国内外首次报道.染色体异态378例,异态率8.76%.结论 在中国不良孕产夫妇中发生的染色体异常主要是染色体结构畸变,异常类型复杂、多样,其中染色体相互易位和罗迫逊易位所占比例最大,并呈现出随着流产次数的增加染色体异常率也增加的趋势.同时,染色体异态在不良孕产夫妇中发生率较高.细胞遗传学分析是不良孕产夫妇病因诊断的一个重要指标.     

中国东北地区人群中不良孕产夫妇的细胞遗传学分析

目的 观察染色体异常在中国东北地区不良孕产夫妇中的分布类型及其与不良孕产的关系.方法 对来自辽宁省生殖健康重点实验室的2158对不良孕产夫妇进行细胞遗传学分析,普通G显带方法分析细胞核型,必要时采用C或R显带方法.结果 在2158对不良孕产夫妇中发现染色体异常137例,异常率为3.17%.其中数目异常3例,结构畸变134例.结构畸变中分别为相互易位90例,罗迫逊易位34例,倒位9例,缺失1例,经中国医学细胞遗传学国家培训中心(湖南)鉴定,43例为国内外首次报道.染色体异态378例,异态率8.76%.结论 在中国不良孕产夫妇中发生的染色体异常主要是染色体结构畸变,异常类型复杂、多样,其中染色体相互易位和罗迫逊易位所占比例最大,并呈现出随着流产次数的增加染色体异常率也增加的趋势.同时,染色体异态在不良孕产夫妇中发生率较高.细胞遗传学分析是不良孕产夫妇病因诊断的一个重要指标.     

Cytogenetic findings in 318 couples with repeated spontaneous abortion: A review of experience in British Columbia

We studied G-banded chromosome complements on 318 couples with 2 or more spontaneous abortions. Seven chromosome abnormalities were detected. Three women and one man were identified as carriers of balanced Robertsonian translocations, t(13;14), t(13;14), t(13;21), and t(14;22), respectively. Aneuploidy: 47,XXX; 47,XX, +marker; and 45,X/46,XX/47,XXX were found in the other 3 women. The overall aberration frequency was 2.2% of couples. When a stringent criterion of ≥ 3 consecutive spontaneous abortions was used, the frequency was 4.2%. In this series no chromosome aberrations were identified in couples with 2 spontaneous abortions and a live-born child with congenital anomalies; 1 of 22 couples with 2 spontaneous abortions and a still-born infant showed a chromosomal abnormality. Findings from the recent literature are compared with those from this study.     

Genetics: Intracytoplasmic sperm injection in infertile patients with structural chromosome abnormalities

In the present study we investigated the results of cyto-geneticanalysis in male and female patients included in an intracytoplasmicsperm injection (ICSI) programme for severe male infertilityas well as in conceptuses resulting from these ICSI treatments.In the 261 couples treated, 11 male (4.2%) and three female(1.2%) abnormal karyotypes were found, all consisting of structuralchromosome anomalies. Chromosomal translocation exhibited thehighest frequency (eight males and two females), and there werealso three cases of chromosomal inversion (two males and onefemale) and one male with one additional marker chromosome.There was no difference in fertilization rates among coupleswith abnormal (n = 14) and normal (n = 147) cytogenetic results,and the rates of clinical pregnancy per ICSI attempt were 25.0%(5/20) and 20.6% (78/378) respectively. In pregnancies obtainedin couples with normal karyotypes, all of the 108 fetuses werefree of chromosomal abnormalities. Among the eight fetuses fromcouples with chromosome structural anomalies, three out of fiveand two out of three inherited the cytogenetic defects foundin their father or mother respectively. In this series of 83ICSI pregnancies there were no chromosomal abnormalities otherthan those inherited from the parents. These findings suggestthat normal pregnancy rates can be obtained by ICSI in casesof chromosomal translocation in couples with severe male infertility.However, until further evaluations of available data can beperformed, cytogenetic analysis must be conducted prior to ICSIin men with low sperm counts, and genetic counselling must includeprenatal diagnosis for all growing conceptuses.     

Chromosome studies in patients with defective reproductive success

PROBLEM: The objective of this study was to evaluate the contribution of chromosomal anomalies to decreased fertility in humans. METHOD OF STUDY: In order to investigate the aetiology of infertility in our population and to assess the karyotype in a group of infertile couples and individuals with fertility problems, 782 persons (259 couples, 158 male and 106 female) with different clinical diagnoses of sterility and infertility were analysed cytogenetically. RESULTS: The overall frequency of major chromosomal aberration was 13.1% (103/783), which suggests that fertility or sterility problems in this population are due to chromosomal aberrations. Couples experiencing repeated spontaneous abortions, having malformed children or having sterility problems had chromosomal abnormalities in 18.0% (47/259 couples) of the population studied, and constituted chromosomal disorders occured in couples seeking IVF and ICSI with prevalence of 22.2% (8/38 couples), especially minor mosaicism of sex chromosomes in the female partners. The prevalence of chromosome abnormalities in infertile men was 17.7% (28/158), and in subfertile females, it was 26.4% (28/106). CONCLUSIONS: These results could indicate an increased tendency to miotic sex chromosome non-disjuction in humans.     

Low-level sex chromosome mosaicism in female partners of couples undergoing ICSI therapy does not significantly affect treatment outcome

BACKGROUND: There is an increased rate of chromosomal anomalies, in particular low-level sex chromosome mosaicism, in the female partners of couples undergoing intracytoplasmic sperm injection (ICSI). METHODS: Among 811 consecutive couples presenting for pre-ICSI chromosome analysis, chromosomal abnormalities were detected in 54 individuals, of which 26 were low-level sex chromosome mosaicism in the females. Attention was focused on the treatment course and outcome of ICSI in 20 couples with low-level sex chromosome mosaicism in the females actually embarking on ICSI treatment (group I, n = 38 ICSI treatment cycles). Applying a case-control design, each of the 20 couples was matched according to female age and source of spermatozoa to couples without a chromosomal abnormality in either of the partners (group II, n = 38 ICSI treatment cycles). RESULTS: No significant differences were found between the groups in ovarian response, fertilization rate and number of embryos transferred. Pregnancy rates, as well as implantation and abortion rates did not differ significantly between the groups. CONCLUSIONS: The data suggest that low-level sex chromosome mosaicism in females has no major effect on the course and outcome of ICSI.