RESUMO
Y chromosome microdeletions can cause male infertility and are classified as natural transmission and de novo mutations. To examine the source of these deletions in Chinese men and to provide a theoretical and laboratory basis for genetic counseling, patients from Northeast China with primary male infertility (N = 22) and their fathers were investigated. Karyotype analysis was performed on peripheral blood lymphocytes using standard G-banding. Multiplex polymerase chain reaction amplification using 18 specific sequence-tagged sites was selected to detect Y chromosome microdeletions. De novo mutations were observed in 17 father-son pairs, leading to a mutation rate of 77.27% (17/22), while the vertical transmission of Yq AZFc microdeletions was detected in 5 cases of the families investigated (29.41%, 5/17). There were no statistically significant differences between vertically transmitted and de novo mutations in men with AZFc deletions regarding age, testicular volume, and reproductive hormone levels. Most Y chromosome microdeletions in men from Northeast China are the result of de novo mutations via natural conception, and men with Yq AZFc deletions showed no clear differences between vertical transmission and de novo mutations.
Assuntos
Povo Asiático/genética , Infertilidade Masculina/genética , Transtornos do Cromossomo Sexual no Desenvolvimento Sexual/genética , China , Bandeamento Cromossômico , Deleção Cromossômica , Cromossomos Humanos Y/genética , Deleção de Genes , Humanos , Cariótipo , Cariotipagem , Masculino , Linhagem , Análise de Sequência de DNA , Sitios de Sequências Rotuladas , Aberrações dos Cromossomos SexuaisRESUMO
A 23-year-old woman who had experienced repeated stillbirths, was found to carry an additional segment on the long arm of the X chromosome. Array comparative genomic hybridization (aCGH) confirmed the origin of the 2 duplications (about 17.11 Mb). Thus, her karyotype was 46, X, dup (X) (q13.2-q21.1), dup(X) (q21.32-q22.1). We demonstrate that aCGH is a useful complementary tool to cytogenetic analysis for accurately determining banding. To our knowledge, this is the first case with normal apparently phenotype who inherited 2 duplications on Xq. Notably, after 2 stillbirths, she bore a healthy, normal female infant via natural pregnancy. Thus, a carrier of this karyotype can birth a phenotypically normal child.
Assuntos
Duplicação Cromossômica , Cromossomos Humanos X , Hibridização Genômica Comparativa/métodos , Aberrações dos Cromossomos Sexuais , Feminino , Triagem de Portadores Genéticos , Humanos , Masculino , Fenótipo , Natimorto , Adulto JovemRESUMO
Successful sperm retrieval from ejaculates of nonmosaic Klinefelter's syndrome (KS) patients by using semen cytology examination was described in this report. The clinical parameters of KS patients with sperm compared to patients without sperm were described. One hundred and fifty-one patients were proven to suffer from KS by chromosomal analysis using G-banding. Spermatozoa were obtained from 10 patients (10/151, 6.6%) using semen analysis. After semen cytology examination, 32 patients (32/151, 21.2%) were found to have sperm or germ cell in their ejaculate. The patients with successful sperm retrieval were significantly younger (27.1 ± 3.7 years) than the patients for whom sperm retrieval failed (28.9 ± 4.2 years). The mean serum testosterone level and the mean T/LH ratio of KS patients with successful sperm retrieval were significantly higher in men with sperm than in men without sperm (testosterone: 3.2 ± 2.1 ng/mL vs 2.7 ± 1.5 ng/mL; T/LH ratio: 0.2 ± 0.3 vs 0.1 ± 0.1). In conclusion, semen cytology examination should be performed to identify sperm and germ cells in the ejaculate of KS patients if no sperm can be detected by traditional semen analysis. The serum testosterone level and T/LH ratio revealed an association between impaired Leydig cell function and impaired spermatogenesis in KS males. KS patients should receive earlier diagnosis and treatment.
Assuntos
Síndrome de Klinefelter/genética , Sêmen , Testículo/patologia , Adulto , Azoospermia/genética , Humanos , Síndrome de Klinefelter/patologia , Masculino , Mosaicismo , Recuperação Espermática , Espermatogênese/genética , Testículo/crescimento & desenvolvimentoRESUMO
The subsequent reproductive outcomes in couples with a history of recurrent pregnancy loss (RPL) associated with chromosome abnormalities or polymorphisms are generally not reported in China. Many RPL carrier couples have decided not to have children. The present study recorded the subsequent delivery, miscarriage, and unpregnancy outcomes of 113 RPL carrier couples and 226 non-carrier couples, and compared differences in reproductive outcomes between couples with different types of chromosome abnormalities or polymorphisms and chromosome normal couples. Our results showed that couples with RPL associated with parental chromosome abnormalities or polymorphisms did not have significantly lower live birth rates than non-carrier couples in China. These results suggest the current guidance given to Chinese RPL couples.
Assuntos
Aborto Habitual/genética , Aberrações Cromossômicas , Polimorfismo Genético , Reprodução/genética , Aborto Habitual/etiologia , Aborto Habitual/patologia , Adulto , China , Feminino , Humanos , Cariotipagem , Masculino , Idade Materna , Pessoa de Meia-Idade , GravidezRESUMO
The prevalence of microdeletions of azoospermia factor (AZF) among azoospermic Klinefelter's syndrome (KFS) patients shows conflicting data. We aimed to detect this frequency in a Northeast Chinese population, and to investigate the possible association between AZF microdeletions and KFS by comparison with previous conflicting reports. Eighty men affected with KFS and a random healthy control group comprising 60 fertile men and women were recruited. AZF microdeletions were detected by multiplex polymerase chain reaction using 9 specific sequence-tagged sites. Karyotype analyses were performed on peripheral blood lymphocytes using standard G-banding. Finally, azoospermia was confirmed in 77 men affected with KFS and no AZF microdeletions were found. Karyotype analysis revealed 1 patient with karyotype 47,XXY,inv (9) (p11, q13), and 2 with mosaic karyotypes (46,XX/47,XXY and 46,XY/47,XXY). All other patients had karyotype 47,XXY. Review of the literature showed that these results were similar to those of other regions of Northeast Asia, but differed from those obtained from Caucasian populations. Our results supported the proposal that AZF microdeletions and KFS result from separate genetic defects. The prevalence of AZF in azoospermic KFS patients varies among populations, and it might result from genetic drift or selective pressure. These results suggest that routine screening for classical AZF microdeletions among infertile azoospermic men with a 47,XXY karyotype might not be necessary in Northeast Chinese individuals. However, it remains imperative for patients considering assisted reproductive treatments, particularly for those with mosaic karyotypes.