Male infertility is a worldwide problem, with a variety of causes including genetic factors. Sex chromosomes are particularly interesting, as males only have a single copy of both chromosomes. The Y chromosome is obviously an area of interest in the study of male-factor infertility because it contains many of the genes that are critical for spermatogenesis and the development of male gonads. Y chromosome microdeletions are the most commonly known genetic causes of spermatogenic failure in males. The azoospermia factor (AZF) region is a particular area on the long arm of the Y chromosome, Yq, where microdeletions occur most frequently. Fourteen Y chromosome genes encoding putatively functional proteins and expressed in the human testis are found to be located in one of the three AZF intervals. The exact role of specific AZF genes in spermatogenesis is largely unknown, for each of the most classical Yq deletions removes multiple genes. The importance of the X chromosome in mammalian spermatogenesis is suggested by its enrichment of germ cell-specific genes expressed in spermatogenesis, such as AR, USP26, TAF7L, TEX11, KAL1, AKAP4, and NXF2. Genes on the X chromosome may be under unique evolutionary pressure due to their hemizygous expression in male. The mutations in the single copy X-linked genes, unlike in autosomal genes, would not be masked by a normal allele. Many researches have been conducted on the relationship between spermatogenesis and the genes on the X chromosome, but the involvement of the X chromosome in male infertility remains less understood and deserves further characterization.
Humans ; Infertility, Male ; genetics ; Male ; Sex Chromosomes

OBJECTIVETo explore the genetics mechanism for the phenotypic variability in a patient carrying a rare ring chromosome 9.

METHODSThe karyotype of the patient was analyzed with cytogenetics method. Presence of sex chromosome was confirmed with fluorescence in situ hybridization. The SRY gene was subjected to PCR amplification and direct sequencing. Potential deletion and duplication were detected with array-based comparative genomic hybridization (array-CGH).

RESULTSThe karyotype of the patient has comprised 6 types of cell lines containing a ring chromosome 9. The SRY gene sequence was normal. By array-CGH, the patient has carried a hemizygous deletion at 9p24.3-p23 (174 201-9 721 761) encompassing 30 genes from Online Mendelian Inheritance in Man.

CONCLUSIONThe phenotypic variability of the 9p deletion syndrome in conjunct with ring chromosome 9 may be attributable to multiple factors including loss of chromosomal material, insufficient dosage of genes, instability of ring chromosome, and pattern of inheritance.

Chromosomes, Human, Pair 9 ; genetics ; Female ; Humans ; Infant ; Karyotype ; Male ; Ring Chromosomes ; Sex Chromosome Disorders ; genetics

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*

OBJECTIVETo explore the relationship between chromosomal abnormalities and Y chromosome microdeletions in idiopathic male infertile patients.

METHODSKaryotypic analysis and PCR were carried out in 133 male idiopathic infertile patients for chromosome karyotype and Y chromosome microdeletion analysis.

RESULTSOf the 133 patients, 25 (18.80%) were found to have chromosome abnormalities, and 12 (9.02%) were found to have Y chromosome microdeletions including 2 with varicocele and 2 with cryptorchism. Four patients had both chromosomal abnormalities and Y chromosome microdeletions.

CONCLUSIONThe chromosomal abnormalities and Y chromosome microdeletions may play an important role in idiopathic male infertility, suggesting the importance of examinations of chromosomal abnormalities and Y chromosome microdeletions in such patients.

Adult ; Chromosome Deletion ; Chromosomes, Human, Y ; genetics ; Humans ; Infertility, Male ; genetics ; Karyotyping ; Male ; Sex Chromosome Aberrations ; Sex Chromosome Disorders of Sex Development ; genetics ; Young Adult

OBJECTIVETo investigate Y chromosome microdeletions in severe oligospermia men with varicocele.

METHODSWe randomly selected 100 cases of severe oligospermia with left varicocele (sperm concentration <5 x 10(6)/ml, group 1), 100 cases of mild oligospermia with left varicocele (sperm concentration 10 -20 x 10(6)/ml, group 2), 100 cases of idiopathic infertility with severe oligospermia (group 3), 100 cases of idiopathic infertility with moderate oligospermia (group 4) and 30 normal fertile men as controls (group 5). We used polymerase chain reaction (PCR) technology to screen 9 sequence tagged sites (STS) of the AZF a, b and c regions and detect Y chromosome microdeletions.

RESULTSAZF microdeletions were found in 19 patients in group 1 (19%) and 11 in group 3 (11%), with a higher rate in the former than in the latter, but not in the other three groups.

CONCLUSIONScreening of Y chromosome microdeletions should be performed before the treatment of severe spermatogenesis with varicocele.

Adult ; Chromosome Deletion ; Chromosomes, Human, Y ; Humans ; Infertility, Male ; genetics ; Male ; Oligospermia ; genetics ; Polymerase Chain Reaction ; Sex Chromosome Aberrations ; Sex Chromosome Disorders of Sex Development ; Varicocele ; genetics

OBJECTIVETo analyze main clinical manifestations and cytogenetic characteristics of patients with a 45,X/46,XY karyotype.

METHODSG-banding karyotype analysis was carried out. PCR was performed to detect azoospermia factor (AZF) microdeletion in adult male patients and sex-determining region on Y chromosome (SRY) gene in all patients. Clinical phenotype and genetic characteristics were summarized.

RESULTSAmong the 9 individuals with 45,X/46,XY, there have been 7 males and 2 females. Six out of the 7 males have manifested primary infertility, which included 5 with azoospermia, 1 with oligospermia, and 1 with hypospadia. Three of the 6 infertile patients were found to have AZF microdeletions. Two females showed typical Turner syndrome. All of the 9 cases were SRY-positive.

CONCLUSIONThe 45,X/46,XY karyotype may result in a range of phenotypes. No correlation has been found between clinical manifestations and proportion of mosaicism cells for their peripheral blood karyotypes. As phenotypically normal male patients may produce sperm, infertile patients should undergo further examination at the molecular level.

Adolescent ; Adult ; Chromosomes, Human, X ; genetics ; Chromosomes, Human, Y ; genetics ; Cytogenetic Analysis ; Female ; Humans ; Infertility, Female ; genetics ; Infertility, Male ; genetics ; Karyotyping ; Male ; Mosaicism ; Sex Chromosome Aberrations ; Young Adult

This article summarizes the structure and heredity characteristics of sex chromosomes and mtDNA, presents the advantages and disadvantages of genetic markers' on them in the practice of forensic medicine which aims at promoting more widely using of the non-euchromosome DNA genetic markers in the forensic science.
Chromosomes, Human, X/genetics* ; Chromosomes, Human, Y/genetics* ; DNA, Mitochondrial/genetics* ; Forensic Medicine ; Genetic Markers/genetics* ; Humans ; Polymerase Chain Reaction ; Sex Factors ; Tandem Repeat Sequences

OBJECTIVETo report a true hermaphroditism due to a teragametic chimerism and to discuss the pathogenesis of tetragametic chimerism.

METHODSChromosomal analysis and fluorescence in situ hybridization(FISH) were carried out on the lymphocytes from the blood and on the fibroblasts from the cultured skin and on fibroblasts from two different kinds of gonadal tissues of the patient with ambiguous genitalia respectively. Blood groups, human leukocyte antigen (HLA) haplotyping and 77 short tandem repeat (STR) microsatellite markers were tested. The two kinds of tissues in the gonad were detected by histopathological examination. Blood groups, HLA haplotying and 77 STR microsatellite markers parents of the patient's were also analyzed.

RESULTSEither 46,XX or 46,XY karyotype was found in the lymphocytes of the blood and in the fibroblasts of the cultured skin and of the two different kinds of gonadal tissues. Two X chromosome-specific signals or one X and one Y signal were detected in each interphase nucleus by FISH from the lymphocytes of the blood and the fibroblasts of three different tissue cultures. The karyotype of the 46,XY cell line predominated in all cultures except the cultured-fibroblasts from yellow gonadal tissues. STR marker analysis, ABO grouping and HLA study from the patient were identified a single haplotype in the patient from the mother and two different haplotypes from the father. Two kinds of tissues in the gonad were observed by histopathological examination. The yellow tissue was ovary and the white one was testis.

CONCLUSIONSHistopathological examination and chromosomal analysis combined with FISH are very useful methods for the diagnosis of true hermaphroditism. Blood typing, HLA and short tandem repeat microsatellite markers afford strong evidence for confirming tetragametic chimerism. The mechanism of tetragametic chimerism in true hermaphroditism can be explained by a parthenogenetic division of a haploid nucleu into two identical gametes, followed by fertilization with both X and Y spermatozoa and then developed into an organism.

ABO Blood-Group System ; Chimera ; Disorders of Sex Development ; blood ; genetics ; pathology ; Female ; Humans ; In Situ Hybridization, Fluorescence ; Male ; Sex Chromosomes

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

OBJECTIVETo investigate the phenotype-genotype association of isodicentromere Y chromosome by analysis of two female patients carrying the chromosome with sexual development disorders.

METHODSThe karyotypes of the two patients were determined by application of conventional G banding of peripheral blood samples and fluorescence in situ hybridization (FISH). PCR was applied to detect the presence of SRY gene.

RESULTSConventional karyotype analysis showed case 1 to be a mosaic: mos.45,X[38]/46,X,+mar[151]/47,XY,+mar[5]/47,X,+mar × 2[2]/46,XY[4], FISH showed that 12 different cell lines were presented in the karyotype of case 1 and partial cell lines with SRY gene, the marker is an isodicentromere Y chromosome [idic(Y)(p)]. No mutation was found in the SRY gene. The karyotype of case 2 was mos.45,X[25]/46,X,+mar[35]. FISH showed the marker to be an idic(Y)(p) without the SRY gene.

CONCLUSIONThe karyotype of patients carrying idic(Y)(p) seems unstable, and female patients have the characteristics of short stature and secondary sexual hypoplasia. Karyotype analysis combined with FISH analysis can accurately determine the breakpoint of idic(Y) and identify the types of complex mosaic, which may facilitate genetic counseling and prognosis.

Adolescent ; Child ; Chromosomes, Human, Y ; Disorders of Sex Development ; genetics ; Female ; Humans ; Karyotype ; Sex Chromosome Aberrations ; Sex-Determining Region Y Protein ; genetics