Spermatogenesis is regulated by several Y chromosome-specific genes located in a specific region of the long arm of the Y chromosome, the azoospermia factor region (AZF). AZF microdeletions are the main structural chromosomal abnormalities that cause male infertility. Assisted reproductive technology (ART) has been used to overcome natural fertilization barriers, allowing infertile couples to have children. However, these techniques increase the risk of vertical transmission of genetic defects. Despite widespread awareness of AZF microdeletions, the occurrence of de novo deletions and overexpression, as well as the expansion of AZF microdeletion vertical transmission, remains unknown. This review summarizes the mechanism of AZF microdeletion and the function of the candidate genes in the AZF region and their corresponding clinical phenotypes. Moreover, vertical transmission cases of AZF microdeletions, the impact of vertical inheritance on male fertility, and the prospective direction of research in this field are also outlined.
Humans ; Male ; Azoospermia/genetics* ; Sex Chromosome Aberrations ; Prospective Studies ; Chromosome Deletion ; Chromosomes, Human, Y/genetics* ; Infertility, Male/genetics* ; Sertoli Cell-Only Syndrome/genetics* ; Oligospermia/genetics*

OBJECTIVE: To assess the value of chromosomal microarray analysis (CMA) and fluorescence in situ hybridization (FISH) for the prenatal diagnosis of chromosomal mosaicisms. METHODS: A total of 775 pregnant women who had visited the Prenatal Diagnosis Center of Yancheng Maternal and Child Health Care Hospital from January 2018 to December 2020 were selected as study subjects. Chromosome karyotyping analysis and CMA were carried out for all women, and FISH was used to validate the suspected mosaicism cases. RESULTS: Among the 775 amniotic fluid samples, karyotyping has identified 13 mosaicism cases, which yielded a detection rate of 1.55%. Respectively, there were 4, 3, 4 and 2 cases for sex chromosome number mosaicisms, abnormal sex chromosome structure mosaicisms, abnormal autosomal number mosaicisms and abnormal autosomal structure mosaicisms. CMA has only detected only 6 of the 13 cases. Among 3 cases verified by FISH, 2 cases were consistent with the karyotyping and CMA results, and clearly showed low proportion mosaicism, and 1 case was consistent with the result of karyotyping but with a normal result by CMA. Eight pregnant women had chosen to terminate the pregnancy (5 with sex chromosome mosaicisms and 3 with autosomal mosaicisms). CONCLUSION For fetuses suspected for chromosomal mosaicisms, CMA, FISH and G-banding karyotyping should be combined to determine the type and proportion of mosaicisms more precisely in order to provide more information for genetic counseling.
Female ; Pregnancy ; Humans ; Mosaicism ; In Situ Hybridization, Fluorescence ; Chromosome Disorders/genetics* ; Prenatal Diagnosis/methods* ; Chromosome Aberrations ; Sex Chromosome Aberrations ; Microarray Analysis/methods* ; Chromosomes

Objective: To analyze the report content, the methods and results of prenatal diagnosis of high risk of sex chromosome aneuploidy (SCA) in non-invasive prenatal testing (NIPT). Methods: A total of 227 single pregnancy pregnant women who received genetic counseling and invasive prenatal diagnosis at Drum Tower Hospital Affiliated to the Medical School of Nanjing University from January 2015 to April 2022 due to the high risk of SCA suggested by NIPT were collected. The methods and results of prenatal diagnosis were retrospectively analyzed, and the results of chromosome karyotype analysis and chromosome microarray analysis (CMA) were compared. The relationship between NIPT screening and invasive prenatal diagnosis was analyzed. Results: (1) Prenatal diagnosis methods for 277 SCA high risk pregnant women included 73 cases of karyotyping, 41 cases of CMA and 163 cases of karyotyping combined with CMA, of which one case conducted amniocentesis secondly for further fluorescence in situ hybridization (FISH) testing. Results of invasive prenatal diagnosis were normal in 166 cases (59.9%, 166/277), and the abnormal results including one case of 45,X (0.4%, 1/277), 18 cases of 47,XXX (6.5%, 18/277), 36 cases of 47,XXY (13.0%, 36/277), 20 cases of 47,XYY (7.2%, 20/277), 1 case of 48,XXXX (0.4%, 1/277), 20 cases of mosaic SCA (7.2%, 20/277), 5 cases of sex chromosome structural abnormality or large segment abnormality (1.8%, 5/277), and 10 cases of other abnormalities [3.6%, 10/277; including 9 cases of copy number variation (CNV) and 1 case of balanced translocation]. Positive predictive value (PPV) for SCA screening by NIPT was 34.7% (96/277). (2) Among the 163 cases tested by karyotyping combined with CMA, 11 cases (6.7%, 11/163) showed inconsistent results by both methods, including 5 cases of mosaic SCA, 1 case of additional balanced translocation detected by karyotyping and 5 cases of additional CNV detected by CMA. (3) NIPT screening reports included 149 cases of "sex chromosome aneuploidy"(53.8%, 149/277), 54 cases of "number of sex chromosome increased" (19.5%, 54/277), and 74 cases of "number of sex chromosome or X chromosome decreased" (26.7%, 74/277). The PPV of "number of sex chromosome increased" and "number of sex chromosome or X chromosome decreased" were 72.2% (39/54) and 18.9% (14/74), respectively, and the difference was statistically significant (χ²=34.56, P<0.01). Conclusions: NIPT could be served as an important prenatal screening technique of SCA, especially for trisomy and mosaicism, but the PPV is comparatively low. More information of NIPT such as the specific SCA or maternal SCA might help improving the confidence of genetic counseling and thus guide clinic management. Multi technology platforms including karyotyping, CMA and FISH could be considered in the diagnosis of high risk of SCA by NIPT.
Female ; Pregnancy ; Humans ; Retrospective Studies ; DNA Copy Number Variations ; In Situ Hybridization, Fluorescence ; Aneuploidy ; Prenatal Diagnosis/methods* ; Sex Chromosome Aberrations ; Sex Chromosomes/genetics*

Alleles ; Amelogenin/genetics* ; Chromosomes, Human, Y ; Humans ; Male ; Sex Determination Analysis

To study the parental origin and cell stage of nondisjunction in sex chromosome aneuploidies. Retrospectiving and analyzing the results of 385 cases of SCA confirmed by QF-PCR and karyotype analysis in the prenatal diagnosis center of Guangzhou Women and Children Medical Center from January 2015 to December 2020. The types of samples and prenatal diagnosis indications were analyzed. The parental origin and cell stage of nondisjunction in sex chromosome aneuploidies analyzed by comparing the short tandem repeat (STR) peak patterns of samples from fetuses and maternal peripheral blood. The results show that (1) There were 324 cases of nonmosaic SCA, 113 cases (113/324, 34.9%) were 45, XO, 118 cases (118/324, 36.4%) were 47, XXY, 48 cases (48/324, 14.8%) were 47, XXX and 45 cases (45/324, 13.9%) were 47, XYY. 68 (45/324, 60.2%) cases of 45, X were detected in villus samples. The other SCA cases were mainly detected in amniotic fluid samples. There were 61 mosaic SCA samples, 58(58/61, 95.1%) of mosaic SCA samples were mosaic 45, X. (2) The top two indications of 45, X cases are increased nuchal translucency(53/113, 46.9%) and fetal cystic hygroma (41/113, 36.3%), while the most common indication of other types of SCA was high risk of NIPT(170/272, 62.5%). (3) Among 45, X cases, there were 88 cases (88/113, 77.9%) inherit their single X chromosome from their mother and 25 cases (25/119, 22.1%) from their father. In 47, XXY samples, 47 cases (47/118, 39.8%) of chromosome nondisjunction occurred in meiosis stage Ⅰ of oocytes, 51 cases (51/118, 43.2%) occurred in meiosis stage Ⅰ of spermatocytes, and 20 cases (20/118, 16.9%) occurred in meiosis stage Ⅱ of oocytes. Among 47, XXX samples, 29 cases (29/48, 60.4%) of X chromosome nondisjunction occurred in meiosis stage Ⅰof oocytes, 15 cases (15/48, 31.3%) occurred in meiosis stage Ⅱ of oocytes, and 4 cases (4/48, 8.3%) occurred in meiosis stage Ⅱ of spermatocytes. In summary , the cases of 45, X were mainly diagnosed by villous samples for abnormal ultrasound findings. The other cases of SCA were mainly diagnosed by amniocentesis samples for abnormal NIPT results. Different types of SCA, the origin and occurrence period of sex chromosome nondisjunction were different.
Aneuploidy ; Female ; Humans ; Karyotyping ; Male ; Pregnancy ; Prenatal Diagnosis/methods* ; Sex Chromosome Aberrations ; Sex Chromosomes/genetics*

OBJECTIVE: To evaluate the efficacy of non-invasive prenatal screening (NIPS) for fetal sex chromosome anomalies. METHODS: A retrospective analysis was carried out for 20 802 women undergoing NIPS screening. For 165 cases suspected for fetal sex chromosomal anomalies, the results of invasive prenatal diagnosis were obtained. RESULTS: Among the 165 cases suspected for fetal sex chromosome anomalies, 129 have accepted invasive prenatal diagnosis, and 45 were confirmed, which yielded a positive predictive value of 34.88%. These included 16 cases of 47,XYY, 10 cases of 47,XXY, 6 cases of 45,X/46,XX, 5 cases of 47,XXX, 3 cases of 45,X, 1 case of 45,X/46,X,i(X)(q10), 1 case of 45,X/46,X,del(X)(q22), 1 case of 46,X,del(X)(q22), 1 case of 46,X,del(X)(p11) and 1 case of Xp22.31 1.2 Mb deletion. CONCLUSION NIPS has limited value for detecting fetal sex chromosome anomalies. Karyotyping analysis combined with other diagnostic techniques can offer effective prenatal diagnosis for suspected cases.
Aneuploidy ; Female ; Humans ; Pregnancy ; Prenatal Diagnosis ; Retrospective Studies ; Sex Chromosomes/genetics* ; Trisomy

OBJECTIVE: To explore the genetic basis of three children with disorders of sex development (DSD) in association with rare Y chromosome rearrangements. METHODS: The three children, who all featured short stature and DSD, were subjected to G banding chromosomal karyotyping, multiplex PCR for Y chromosomal microdeletion, sequencing of the whole SRY gene, SNP-array analysis for genomic copy number variations, and fluorescence in situ hybridization (FISH). RESULTS: The combined analysis revealed chromosomal abnormalities in all of the three children, including 46,X,t(X;Y)(p22.3;q11.2) in case 1, mos 45,X,der(7)pus dic(Y:7)(p11.3p22)del(7)(p21.2p21.3) del(7)(p12.3p14.3) [56]/45,X [44] in case 2, and mos 45,X [50]/46,X,idic(Y)(q11.22) [42]/47,X,idem×2 [4]/47,XYY [2] in case 3. CONCLUSION Combined use of genetic techniques can delineate complex rearrangements involving Y chromosome in patients featuring short stature and DSD. Above findings have enabled molecular diagnosis and genetic counseling for the patients.
Child ; Chromosome Banding ; Chromosomes, Human, Y/genetics* ; DNA Copy Number Variations ; Humans ; In Situ Hybridization, Fluorescence ; Male ; Polymorphism, Single Nucleotide ; Sex Chromosome Aberrations ; Sex Chromosome Disorders of Sex Development/genetics*

OBJECTIVE: To analyze the impact of maternal age on sex chromosome aneuploidies (SCA). METHODS: Pregnant women who had karyotype analysis of amniotic fluid in Women's Hospital, Zhejiang University School of Medicine from January 2014 to July 2018 were recruited. The association of the maternal age with fetal SCAs was analyzed. RESULTS: The incidence of 45, X in age group >34-<38 was lower than that of ≤ 28 age group (<0.05). For the incidences of total sex chromosome trisomy and 47, XXY in age groups 34-<38 and ≥38 were higher than age groups ≤28 and >28-34 (<0.05 or <0.01). The incidence of 47, XXX in age group ≥ 38 was higher than that in age group>28-34 (<0.05). However, the incidence of 47, XYY had no differences among the four groups (>0.05). After excluding the high risk of sex chromosome abnormalities by non-invasive prenatal testing (NIPT), we found that for 45, X, the incidences of two groups with advanced age were lower than that of ≤ 28 year-old group of age group (<0.05 or <0.01), and incidence in age group >34-<38 was also lower than that in age group >28-34 (<0.05). The other results were consistent with those without excluding the high risk of sex chromosome abnormalities by NIPT. CONCLUSIONS Advanced age decreases the incidence of 45, X, but increases the risk of sex chromosome trisomy, especially 47, XXX and 47, XXY.
Adult ; Age Factors ; Female ; Humans ; Maternal Age ; Pregnancy ; Prenatal Diagnosis ; Sex Chromosome Aberrations ; statistics & numerical data ; Sex Chromosomes ; genetics ; Trisomy

OBJECTIVE: To delineate cytogenetic and molecular abnormalities of a fetus carrying a de novo 46,X,der(X),t(X;Y)(p22.3;p11.2). METHODS: G-banded karyotyping and next-generation sequencing (NGS) were used to analyze the fetus, his father and sister. Single nucleotide polymorphism-based arrays (SNP-array), multiple PCR and fluorescence in situ hybridization (FISH) were utilized to verify the result. RESULTS: G-banded karyotyping at 320 bands showed that the fetus had a normal karyotype, while NGS has identified a 3.58 Mb microdeletion at Xp22.33 and a Y chromosomal segment of about 10 Mb at Yp11.32p11.2. With the sequencing results, high-resolution karyotyping at 550-750 bands level has determined the fetus to be 46,X,der(X)t(X;Y)(p22.3;p11.2). The result was confirmed by PCR amplification of the SRY gene, FISH and SNP-array assays. The karyotypes of his father and sister were both normal. His sister also showed no amplification of the SRY gene, and her NGS results were normal too, suggesting that the karyotype of the fetus was de novo. CONCLUSION Combined karyotyping, NGS, SNP-array, PCR and FISH assay can facilitate diagnosis of XX disorder of sex development.
Chromosomes, Human, X ; genetics ; Disorders of Sex Development ; genetics ; Female ; Fetus ; Humans ; In Situ Hybridization, Fluorescence ; Karyotyping ; Male ; Polymerase Chain Reaction ; Polymorphism, Single Nucleotide ; Translocation, Genetic

OBJECTIVETo explore the correlation between cytogenetic findings and clinical manifestations of Turner syndrome.

METHODS607 cases of cytogenetically diagnosed Turner syndrome, including those with a major manifestation of Turner syndrome, were analyzed with conventional G-banding. Correlation between the karyotypes and clinical features were analyzed.

RESULTSAmong the 607 cases, there were 154 cases with monosomy X (25.37%). Mosaicism monosomy X was found in 240 patients (39.54%), which included 194 (80.83%) with a low proportion of 45,X (3 ≤ the number of 45, X ≤5, while the normal cells ≥ 30). Structural X chromosome abnormalities were found in 173 patients (28.50%). A supernumerary marker chromosome was found in 40 cases (6.59%). Most patients with typical manifestations of Turner syndrome were under 11 years of age and whose karyotypes were mainly 45,X. The karyotype of patients between 11 and 18 years old was mainly 45,X, 46,X,i(X)(q10) and mos45,X/46,X,i(X)(q10), which all had primary amenorrhea in addition to the typical clinical manifestations. The karyotype of patients over 18 years of age were mainly mosaicism with a low proportion of 45,X, whom all had primary infertility. 53 patients had a history of pregnancy, which included 48 with non-structural abnormalities of X chromosome and 5 with abnormal structure of X chromosome.

CONCLUSIONGenerally, the higher proportion of cells with an abnormal karyotype, the more severe were the clinical symptoms and the earlier clinical recognition. Karyotyping analysis can provide guidance for the early diagnosis of Turner syndrome, especially those with a low proportion of 45,X.

Abortion, Spontaneous ; genetics ; Adolescent ; Adult ; Amenorrhea ; genetics ; Child ; Child, Preschool ; Chromosomes, Human, X ; genetics ; Cytogenetic Analysis ; methods ; Female ; Humans ; Infant ; Infant, Newborn ; Karyotyping ; Middle Aged ; Mosaicism ; Pregnancy ; Sex Chromosome Aberrations ; Turner Syndrome ; genetics ; pathology ; Young Adult