The value of chromosomal microarray analysis and fluorescence in situ hybridization for the prenatal diagnosis of chromosomal mosaicisms / 中华医学遗传学杂志

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.

Microdeletions and vertical transmission of the Y-chromosome azoospermia factor region / 亚洲男科学杂志(英文版)

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.

Prenatal diagnosis and genetic analysis of two cases of Turner syndrome due to isodicentric Xp11.22 / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic characteristics of idic(X)(p11.22) in Turner syndrome (TS).@*METHODS@#Two fetuses suspected for sex chromosome abnormalities or ultrasound abnormalities were selected from Chengdu Women's and Children's Central Hospital in October 2020 and June 2020, and amniotic fluid samples were collected for G-banded chromosomal karyotyping analysis, chromosomal microarray analysis (CMA), and fluorescence in situ hybridization (FISH).@*RESULTS@#The two fetuses were respectively found to have a karyotype of 45,X[47]/46,X,psu idic(X)(p11.2)[53] and 46,X,psu idic(X)(p11.2). CMA found that both had deletions in the Xp22.33p11.22 region and duplications in the p11.22q28 region. FISH showed that the centromeres in both fetuses had located on an isochromosome.@*CONCLUSION@#The combination of karyotyping analysis, FISH, and CMA is useful for the delineation of complex structural chromosomal aberrations. High-resolution CMA can accurately identify chromosomal breakpoints, which can provide a clue for elucidating the mechanism of chromosomal breakage and rearrangement.

Clinical application and evaluation of health economics for non-invasive prenatal testing of fetuses in Tianjin / 中华医学遗传学杂志

OBJECTIVE@#To assess the clinical efficacy and health economic value of non-invasive prenatal testing (NIPT) for the prenatal screening of common fetal chromosomal aneuploidies.@*METHODS@#10 612 pregnant women from October 2017 to December 2019 presented at the antenatal screening clinic of the General Hospital of Tianjin Medical University were selected as the study subjects. Results of NIPT and invasive prenatal diagnosis and follow-up outcome for the 10 612 pregnant women were retrospectively analyzed and compared. Meanwhile, NIPT data for two periods were analyzed for assessing the health economic value of NIPT as the second- or first-tier screening strategy for the prenatal diagnosis of fetal trisomies 21, 18 and 13.@*RESULTS@#The NIPT was successful in 10 528 (99.72%) subjects, with the sensitivity for fetal trisomies 21, 18 and 13 being 100%, 92.86% and 100%, and the positive predictive value (PPV) being 89.74%, 61.90% and 44.44%, respectively. The PPV of NIPT for sex chromosome aneuploidies was 34.21%. Except for one false negative case of trisomy 18, the negative predictive value for trisomy 21, trisomy 13 and other chromosomal abnormalities were 100%. For pregnant women with high risk by serological screening, advanced maternal age or abnormal ultrasound soft markers, NIPT has yielded a significantly increased high risk ratio. There was no statistical difference in the PPV of NIPT among pregnant women from each subgroup. NIPT would have higher health economic value as a second-tier screening until 2019, while compared to 2015 ~ 2017, its incremental cost-effectiveness ratio as a first-tier screening had declined clearly.@*CONCLUSION@#The screening efficacy of NIPT for trisomies 21, 18 and 13 for a mixed population is significantly better than conventional serological screening, but it is relatively low for sex chromosomal abnormalities. NIPT can also be recommended for populations with relatively high risks along with detailed pre- and post-test genetic counselling. From the perspective of health economics, except for open neural tube defects, it is possible for NIPT to replace the conventional serological screening in the future as its cost continues to decrease.

Comparison of detection rates of chromosome G-banding karyotype analysis and fluorescence in situ hybridization among children with sex chromosome mosaicisms / 中华医学遗传学杂志

OBJECTIVE@#To explore the coincidence rate of G-banding karyotype analysis and fluorescence in situ hybridization (FISH) for the diagnosis of children with sex chromosome mosaicisms.@*METHODS@#A retrospective analysis was carried out for 157 children with suspected sex chromosome abnormalities who had presented at Shenzhen Children's Hospital from April 2021 to May 2022. Interphase sex chromosome FISH and G-banding karyotyping results were collected. The coincidence rate of the two methods in children with sex chromosome mosaicisms was compared.@*RESULTS@#The detection rates of G-banding karyotype analysis and FISH were 26.1% (41/157) and 22.9% (36/157) , respectively (P > 0.05). The results of G-banding karyotype analysis showed that 141 cases (89.8%) were in the sex chromosome homogeneity group, of which only 5 cases (3.5%) were inconsistent with the results of FISH. There were 16 cases (10.2%) in the sex chromosome mosaicism group, of which 11 cases (68.8%) were inconsistent with the results of FISH. There was a statistical difference between the two groups in the coincidence rate of the results of the two methods (P < 0.05).@*CONCLUSION@#No significant difference was found between G-banding karyotype analysis and FISH in the detection rate of chromosome abnormalities. The coincidence rate in the mosaicism group was lower than that in the homogeneity group, and the difference was statistically significant. The two methods should be combined for clinical diagnosis.

Molecular studies on parental origin and cell stage of nondisjunction in sex chromosome aneuploidies / 中华预防医学杂志

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.

Analysis of the effect of expanded non-invasive prenatal testing in prenatal screening population during pregnancy / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical effect of expanded non-invasive prenatal testing (NIPT-plus) for prenatal screening.@*METHODS@#The screening result, prenatal diagnosis and pregnancy outcome of 3700 pregnant women who volunteered NIPT-plus screening at our center from September 2018 to December 2019 were reviewed.@*RESULTS@#Among the 3700 pregnant women, 74(2.0%) were scored positive for clinically significant fetal chromosomal abnormalities and underwent NIPT-plus screening. Sixty three women with a high risk underwent invasive prenatal diagnosis, among whom 19 were diagnosed, which yielded a positive predictive value (PPVs) of 30.2% (19/63). Statistical analysis showed that NIPT-plus has higher PPVs for common aneuploidies and low-to-medium PPVs for sex chromosome aneuploidies and microdeletion/microduplication syndromes.@*CONCLUSION@#As a screening technique, NIPT-plus has broader applications compared with conventional techniques, and has reference value for clinicians and pregnant women during pregnancy.

Clinical characteristics and prenatal diagnosis of fetuses with sex chromosomal aneuploidies detected by non-invasive prenatal testing during early and midterm pregnancies / 中华医学遗传学杂志

OBJECTIVE@#To analyze the indication, karyotyping result, ultrasound finding, pregnancy decision and follow-up of fetuses with sex chromosome aneuploidies (SCA) detected by non-invasive prenatal testing (NIPT) during early and midterm pregnancies.@*METHODS@#The results of 225 singleton pregnancies with fetal SCA detected by NIPT were reviewed and analyzed.@*RESULTS@#The 225 cases included 45,X (n=37), 47,XXY (n=74), 47,XXX (n=50), 47,XYY (n=56) and mosaicisms (n=8), among which 121 (53.8%) have opted to terminate the pregnancy, including 45,X (n=31), 47,XXY (n=61), 47,XXX (n=14), 47,XYY (n=12) and 3 mosaicisms. The remainder 104 (46.2%) have elected to continue with the pregnancy, among which three have opted to terminate due to abnormalities detected by ultrasonography, and two had spontaneous abortions.@*CONCLUSION@#NIPT as a first-tier screening method can effectively detect fetal trisomies 21, 13 and 18 as well as SCA. The types of fetal SCA and presence of ultrasound abnormalities are critical factors for the termination of pregnancy.

High frequency of Y chromosome microdeletions in male infertility patients with 45,X/46, XY mosaicism

The mosaic 45,X/46,XY karyotype is a common sex chromosomal abnormality in infertile men. Males with this mosaic karyotype can benefit from assisted reproductive therapies, but the transmitted abnormalities contain 45,X aneuploidy as well as Y chromosome microdeletions. The aim of this study was to investigate the clinical and genetic characteristics of infertile men diagnosed with 45,X/46,XY mosaicism in China. Of the 734 infertile men found to carry chromosomal abnormalities, 14 patients were carriers of 45,X/46,XY mosaicism or its variants, giving a prevalence of 0.27% (14/5269) and accounting for 1.91% (14/734) of patients with a chromosomal abnormality. There were ten cases (71.43%, 10/14) of 45,X mosaicism exhibiting AZF microdeletions. Case 1 and Case 4 had AZFc deletions, and the other eight cases had AZFb+c deletions. A high frequency of Y chromosome microdeletions were detected in male patients with 45,X/46,XY mosaicism. Preimplantation genetic diagnosis should be offered to men having intracytoplasmic sperm injection for hypospermatogenesis caused by 45,X/46,XY mosaicism, to avoid the risk of transfering AZF microdeletions in addition to X monosomy in male offspring.

Genetic analysis of three children with disorders of sex development caused by structural rearrangements of Y chromosome / 中华医学遗传学杂志

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.

El intersticio pulmonar y sus enfermedades en la infancia. Confusión diagnóstica en el recién nacido. Enfermedades genéticas del surfactante pulmonar. A propósito de un caso clínico: clínica, radiología, estudios y diagnóstico diferencial / The pulmonary interstitium and its diseases in childhood. Diagnostic confusion in the new born. Genetic diseases of pulmonary surfactant. About a clinical case: clinical, radiology, studies and differential diagnosis

Se presenta el caso clínico de un lactante fallecido a los siete meses de edad con cuadro intersticial persistente. Objetivos: describir detalladamente el camino diagnóstico; alertar sobre posibles confusiones en recién nacidos con diagnósticos más frecuentes; detallar los hallazgos clínicos, radiológicos y de anatomía patológica (consultas en el exterior). Metodología: sumatoria de estudios complejos para descartar causas más frecuentes de patología intersticial en el lactante; consultas radiológicas, de anatomía patológica y genética en el exterior del país. Resultado: con diagnóstico de PAP (proteinosis alveolar pulmonar) se encontró una duplicación de material genético a nivel de cromosoma X, correspondiente al gen CSF2RA (colony stimulating factor 2-subunidad a). Este gen codifica al receptor CSF2 cuya citoquina controla la producción, diferenciación y función de granulocitos/macrófagos. (AU)

A clinical case of a deceased seven month old infant presenting persistent interstitial lung compromise is presented. Objectives. Detailed description of the diagnostic pathway used; to alert about possible confusion with other ­ more frequent ­ pathologies in the new borninfant age; to present clinical, radiological, genetic and pathology findings (consultations abroad). Methodology. A complete description of complex studies to rule out other more frequent pathologies is presented together with radiological, pathological and genetic results from consultations abroad. Results. A diagnosis of PAP (pulmonary alveolar proteinosis) was confirmed with duplication of genetic material at CSF2RA gene (colony stimulating factor 2-subunit a). This gene codifies the CSF2 receptor whose cytokine controls production, differentiation and function of granulocytes/macrophages. (AU)

Association of maternal age with fetal sex chromosome aneuploidies / 浙江大学学报·医学版

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 >34-28-34 (28-34 (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 (34-28-34 (<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.

A case of maternal 45,X/46,XX mosaicism detected by non-invasive prenatal testing / 中华医学遗传学杂志

OBJECTIVE@#To report on a case of maternally derived 45,X mosaicism detected by non-invasive prenatal testing (NIPT).@*METHODS@#Fetal sex chromosomal abnormality was detected by NIPT. Maternally derived 45,X mosaicism was confirmed by chromosome karyotype analysis. Fetal sex chromosome aneuploidy was detected by amniotic fluid chromosome microarray analysis.@*RESULTS@#A maternal 45,X mosaicism was diagnosed. The fetus was confirmed to be normal.@*CONCLUSION@#Maternal 45,X masaicism can be diagnosed by NIPT.

Association of abnormal length of Y chromosome with semen quality and outcome of assisted reproductive technology in humans / 中华男科学杂志

Objective@#To investigate the association of the abnormal length of human Y chromosome with semen quality and the outcome of assisted reproductive technology (ART).@*METHODS@#Based on the karyotype, we assigned the patients undergoing ART to a normal control, a long Y chromosome (Y>18), and a short Y chromosome group (Y18 group showed a significantly lower incidence rate of asthenozoospermia (31.03% vs 8.33%, P 18 and Y0.05).@*CONCLUSIONS@#Short Y chromosome may affect spermatogenesis, but the length of Y chromosome does not negatively influence the outcome of ART.

Clinical manifestation and cytogenetic analysis of 607 patients with Turner syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the correlation between cytogenetic findings and clinical manifestations of Turner syndrome.</p><p><b>METHODS</b>607 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.</p><p><b>RESULTS</b>Among 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.</p><p><b>CONCLUSION</b>Generally, 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.</p>

Incidence of Y-chromosome microdeletions in children whose fathers underwent vasectomy reversal or in vitro fertilization with epididymal sperm aspiration: a case-control study / Incidência de microdeleções do cromossomo Y em filhos de pais que passaram por reversão de vasectomia ou fertilização in vitro com aspiração do epidídimo: um estudo caso-controle

ABSTRACT Objective To evaluate the incidence of Y-chromosome microdeletions in individuals born from vasectomized fathers who underwent vasectomy reversal or in vitro fertilization with sperm retrieval by epididymal aspiration (percutaneous epididymal sperm aspiration). Methods A case-control study comprising male children of couples in which the man had been previously vasectomized and chose vasectomy reversal (n=31) or in vitro fertilization with sperm retrieval by percutaneous epididymal sperm aspiration (n=30) to conceive new children, and a Control Group of male children of fertile men who had programmed vasectomies (n=60). Y-chromosome microdeletions research was performed by polymerase chain reaction on fathers and children, evaluating 20 regions of the chromosome. Results The results showed no Y-chromosome microdeletions in any of the studied subjects. The incidence of Y-chromosome microdeletions in individuals born from vasectomized fathers who underwent vasectomy reversal or in vitro fertilization with spermatozoa recovered by percutaneous epididymal sperm aspiration did not differ between the groups, and there was no difference between control subjects born from natural pregnancies or population incidence in fertile men. Conclusion We found no association considering microdeletions in the azoospermia factor region of the Y chromosome and assisted reproduction. We also found no correlation between these Y-chromosome microdeletions and vasectomies, which suggests that the assisted reproduction techniques do not increase the incidence of Y-chromosome microdeletions.

RESUMO Objetivo Avaliar a incidência de microdeleções do cromossomo Y em indivíduos nascidos de pais vasectomizados submetidos à reversão de vasectomia ou fertilização in vitro com recuperação de espermatozoides por aspiração do epidídimo (aspiração percutânea de espermatozoides do epidídimo). Métodos Estudo caso-controle que compreende crianças do sexo masculino de casais em que o homem havia sido previamente vasectomizado e escolheu reversão da vasectomia (n=31) ou fertilização in vitro com recuperação espermática por aspiração percutânea de espermatozoides do epidídimo (n=30) para obtenção de novos filhos, e um Grupo Controle de crianças do sexo masculino de homens férteis com vasectomia programada (n=60). A pesquisa de microdeleções do cromossomo Y foi realizada por reação em cadeia da polimerase nos pais e filhos, avaliando 20 regiões do cromossomo. Resultados O resultado não revelou microdeleções do cromossomo Y em qualquer indivíduo estudado. A incidência de microdeleções do cromossomo Y em indivíduos nascidos de pais vasectomizados que sofreram reversão de vasectomia ou fertilização in vitro com espermatozoides recuperados pela aspiração percutânea de espermatozoides do epidídimo não diferiu entre os grupos, e não houve nenhuma diferença entre indivíduos controle nascidos de gestações naturais ou incidência populacional em homens férteis. Conclusão Não foi encontrada nenhuma associação considerando microdeleções da região do fator de azoospermia no cromossomo Y e reprodução assistida. Não houve correlação entre microdeleções do cromossomo Y e vasectomia, o que sugere que as técnicas de reprodução assistida não aumentam a incidência de microdeleções do cromossomo Y.

Familial fragile X syndrome: A pedigree analysis / 中华男科学杂志

<p><b>Objective</b>To investigate the clinical (including reproductive) manifestations and genetic characteristics of familial fragile X syndrome (FXS).</p><p><b>METHODS</b>We collected the clinical data about a case of familial FXS by inquiry, testicular ultrasonography, semen analysis, determination of sex hormone levels, and examinations of the peripheral blood karyotype and Y chromosome microdeletions. Using Southern blot hybridization, we measured the size of the CGG triple repeat sequence of the fragile X mental retardation-1 (FMR1) gene and determined its mutation type of the pedigree members with a genetic map of the FXS pedigree.</p><p><b>RESULTS</b>Among the 34 members of 4 generations in the pedigree, 3 males and 1 female (11.76%) carried full mutation and 9 females (26.47%) premutation of the FMR1 gene. Two of the males with full FMR1 mutation, including the proband showed a larger testis volume (>30 ml) and a higher sperm concentration (>250 ×10⁶/ml), with a mean sperm motility of 50.5%, a mean morphologically normal sperm rate of 17.5%, an average sperm nuclear DNA fragmentation index (DFI) of 18.5%, a low level of testosterone, normal karyotype in the peripheral blood, and integrity of the azoospermia factor (AZF) region in the Y chromosome. One of the second-generation females carrying FMR1 premutation was diagnosed with premature ovarian failure and another 3 with uterine myoma.</p><p><b>CONCLUSIONS</b>Some of the FXS males in the pedigree may present macroorchidism and polyzoospermia but with normal semen parameters. In the intergenerational transmission, premutation might extend to full mutation, with even higher risks of transmission and extension of mutation in males, especially in those with >80 CGG triple repeat sequences. Therefore, it is recommended that the couples wishing for childbearing receive genetic testing, clinical guidance, and genetic counseling before pregnancy and, if necessary, prenatal diagnosis and preimplantation genetic diagnosis.</p>

Cytogenetic and molecular genetic analysis of a case with mosaic marker chromosomes / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the source of small supernumerary marker chromosome in a case.</p><p><b>METHODS</b>G-banded karyotyping, fluorescence in situ hybridization, multiple sequence tagged sites (STS) of the Y chromosome, and Illumima Human Cyto SNP-12 Beadchip analysis were carried out.</p><p><b>RESULTS</b>The karyotype was mos 46,X,+mar1[21]/46,X,+mar2[78]. Y chromosome STS analysis has displayed the presence of sy84, sY86, USP9Y and DDX3Y genes from the AZFa region, and sY1227 of the AZFb region, while sY1228, sY1015, sY127, sY134 from the AZFb region, and sY254 and sY255 from the AZFc region were missing. FISH analysis has verified both of the marker chromosomes to be Y chromosome fragments. Mar1 was ish.idic(Y)(q11.2)(SRY++,DXZ1+,DYZ3++,DYZ1-), while mar2 was ish.del(Y)(q11.2)(SRY+,DXZ1+,DYZ3+,DYZ1-). Single nucleotide polymorphism (SNP) microarray analysis showed that the Yq11.2-Yq12 has lost a 10.81 Mb fragment.</p><p><b>CONCLUSION</b>The marker chromosomes were verified to be aberrant Y chromosomes, with the breakage and recombination occurring in Yq11.2. Mar 1 was an isodicentric Y chromosome (idic(Y)pter to q11.2::q11.2 to pter), and mar2 was del(Y)(q11.2). The karyotype was mos 46,X,ish idic(Y)(q11.2)(DYZ3++,SRY++,DXZ1+,DYZ1-)[21]/46,X,ish del(Y)(q11.2)(DYZ3+,SRY+,DXZ1+,DYZ1-)[78]. Combined FISH, Y chromosome STS analysis, SNP microarray analysis and other technologies can facilitate determination of the nature of marker chromosomes.</p>

Genetic analysis for 2 females carrying idic(Y)(p) and with sex development disorders / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the phenotype-genotype association of isodicentromere Y chromosome by analysis of two female patients carrying the chromosome with sexual development disorders.</p><p><b>METHODS</b>The 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.</p><p><b>RESULTS</b>Conventional 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.</p><p><b>CONCLUSION</b>The 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.</p>

Prenatal diagnosis of an unbalanced translocation between chromosome Y and chromosome 15 in a female fetus

We report the prenatal diagnosis of an unbalanced translocation between chromosome Y and chromosome 15 in a female fetus. Cytogenetic analysis of parental chromosomes revealed that the mother had a normal 46,XX karyotype, whereas the father exhibited a 46,XY,der(15)t(Y;15) karyotype. We performed cytogenetic analysis of the father's family as a result of the father and confirmed the same karyotype in his mother and brother. Fluorescence in situ hybridization and quantitative fluorescent-polymerase chain reaction analysis identified the breakpoint and demonstrated the absence of the SRY gene in female members. Thus, the proband inherited this translocation from the father and grandmother. This makes the prediction of the fetal phenotype possible through assessing the grandmother. Therefore, we suggest that conventional cytogenetic and molecular cytogenetic methods, in combination with family history, provide informative results for prenatal diagnosis and prenatal genetic counseling.