Presence Of Microdeletions Research Articles

Primer infertil erkeklerdeki Y-kromozom mikrodelesyon sıklığı

OBJECTIVES: There are SRY (sex-determining region Y) region, which plays a role in testicular development, and genes related to spermatogenesis on the Y chromosome. Its long arm contains the azoospermia factor (AZF) region (AZFa, AZFb, and AZFc subregions). Microdeletions in this region are responsible for azoospermia and oligospermia and cause male infertility. The aim of this study was to analyze the incidence of microdeletion in the AZF region of the Y chromosome in male patients with primary infertility with azoospermia and oligospermia. MATERIAL and METHODS: A total of 206 male patients were analyzed between December 2020 and December 2022. The diagnosis of azoospermia and oligospermia was made based on semen analysis. Patients with normal karyotype were included in the study. For the definitive diagnosis of microdeletions in the AZF region, 20 different sequence tagged sites (STS) were used, including the recommendation of the European Academy of Andrology (EAA) and the European Molecular Genetics Quality Network (EMQN). Each region was amplified by polymerase chain reaction (PCR) method and analyzed by fragment method in ABI 3500 DNA Sequence instrument. RESULTS: Microdeletion was detected in the AZF region of the Y chromosome in 17 of 206 patients (8%, 3) with normal karyotype. With the study, we identified the deletions of each subregion of AZF in our population. The presence of microdeletions in the AZFc region was most common. b2/b4 complete AZF/c microdeletions were higher than the g/gr partial AZF/c deletion. CONCLUSION: The study confirmed that the incidence of microdeletion of AZF subregions in primary infertile male patients was 8%,3 and was prognostically significant. The frequency of Y chromosome microdeletion was found to be consistent with the literature. Keywords: AZF region, azoospermia, oligospermia, primary male infertility, Y-chromosome microdeletion

Пренатальная диагностика оро-фацио-дигитального синдрома I типа у плода с частичной моносомией Хр22.2

Представлен первый случай пренатальной диагностики оро-фацио-дигитального синдрома I типа (OMIM 311200) у плода с частичной моносомией Хр22.2. Причиной оро-фацио-дигитального синдрома I типа являются мутации в гене OFDI, случаи заболевания вследствие хромосомных микроделеций, затрагивающих ген OFDI встречаются редко. При ультразвуковом исследовании плода во втором триместре беременности выявлены врожденный порок развития головного мозга и множественные эхографические маркеры хромосомной и синдромальной патологии. Биологический образец плода (пуповинная кровь) получен в 21 неделю гестации посредством кордоцентеза. Молекулярно-цитогенетический анализ ДНК, выделенной из лимфоцитов пуповинной крови плода, с применением матричной сравнительной геномной гибридизации выявил частичную моносомию региона Хр22.2, размером 2,6 млн п.н.: arr[hg19] Xp22.2(11135472_13798048)×1. Наличие перестройки, а также ее de novo происхождение, подтверждено количественной ПЦР в режиме реального времени. The first case of prenatal diagnosis of type I oro-facio-digital syndrome (OMIM 311200) in fetus with partial monosomy Xp22.2 is presented. The cause of type I oro-facio-digital syndrome is mutations in the OFDI gene, cases of disease due to chromosomal microdeletions affecting the OFDI gene are rare. Ultrasound examination of the fetus in the second trimester of pregnancy revealed congenital defect of brain development and multiple echographic markers of chromosomal and syndrome pathology. An umbilical cord blood was obtained in 21 weeks of gestation by cordocentesis. aCGH revealed partial monosomy Xp22.2 at 2.6 Mb in size: arr [hg19] Xp22.2(11135472_13798048) × 1. The presence of microdeletion, as well as its de novo origin, was confirmed by the quantitative real time PCR. The use of high-resolution molecular cytogenetic analysis significantly expands the possibilities of syndrome monogenic pathology diagnosis in the prenatal period.

Genetic testing and prenatal diagnosis of X-linked ichthyosis in two pedigrees

Objective To analyze genetic testing and prenatal diagnosis of two pedigrees with X-linked ichthyosis. Methods Karyotyping, bacterial artificial chromosomes-on-BeadsTM (BoBs), fluorescence in situ hybridization (FISH) and single nucleotide polymorphism array (SNP-array) were used to detect amniotic fluid and peripheral blood specimens of two pedigrees, one with and one without known family history of ichthyosis. Clinical data was collected and analyzed as well. Results (1) The pedigree without known family history: Prenatal BoBs showed that the XC1 probe of fetusⅣ-12 was from 0.36 to 0.50, suggesting the presence of microdeletion. SNP-array analysis of gravidaⅢ-13 showed a 1.68 Mb copy number deletion at Xp22.31 and four missing Online Mendelian Inheritance in Man (OMIM) genes (HDHD1, STS, VCX and PNPLA4). Fetal SNP-array revealed a deletion of arr[hg19] Xp22.31 (6 455 151-8 135 644)×0, indicating a maternally inherited one. FISH analysis verified the deletion in STS gene in fetus Ⅳ-12, whose karyotype was 46, XY. The gravida's female cousin (Ⅲ-21) and nephew (Ⅳ-14) also had STS gene deletion, which size was the same as that from the gravida and the fetus. Fetus (Ⅳ-12) was delivered at term by cesarean section with normal skin, but an extensive white scales appeared on the abdomen one week after birth and the symptom was aggravated when the weather was dry. The infant was followed up to eight months old and no other clinical symptoms were found. (2) The pedigree with known family history: SNP-array revealed that a 1.2 Mb copy number deletion at Xp22.31 and four missing OMIM genes (HDHD1, STS, VCX and PNPLA4) were detected in pregnant women (Ⅲ-21), proband (Ⅳ-16) and fetus (Ⅳ-17). FISH analysis of the fetus verified the deletion in STS gene. The karyotype of the fetus was 46, XY. FetusⅣ-17 was delivered at term by cesarean section with normal skin, but white scales widely appeared on the abdomen ten days after birth. The infant was followed up to four months old and no other clinical symptoms were found. Conclusion Molecular genetic techniques such as BoBs, FISH and SNP-array are used in combination in this study to provide genetic testing and prenatal diagnosis to two XLI pedigrees, which is helpful for clinical diagnosis and genetic counseling. Key words: Ichthyosis, X-linked; Pedigree; Steryl-sulfatase; Prenatal diagnosis; Genetic testing

Cytogenetic Abnormalities and Y Chromosome Microdeletions in Azoospermic and Oligospermic Infertile Males from West of Iran

About 15% of couples have infertility problems, half of which are related to male factors. Cytogenetic and genetic disorders account for about 10% of the male infertility problems. The aim of this study was to determine the frequency and types of both cytogenetic abnormalities and AZF microdeletions of Y chromosome in idiopathic azoospermic and oligospermic infertile men in west of Iran. In this case-control study, a total of 108 infertile men including 62 azoospermic and 46 oligospermic men were studied for the cytogenetic and AZF microdeletions. Moreover, 90 fertile men served as a control group. Detailed clinical and laboratory examination was done for all participants. Karyotyping was done on peripheral blood lymphocytes to detect the cytogenetic abnormalities; likewise, multiplex-PCR method was performed to identify the presence of microdeletion in AZFa, AZFb or AZFc regions. Chromosomal abnormalities were detected in 6.5% (7/108) of cases, including two oligospermic men with balanced autosomal rearrangements, one oligospermic and four azoospermic men with Klinefelter syndrome. Y chromosome microdeletions were detected in 4.6% (5/108) of infertile men (AZFc: 3.7%, AZFbc: 0.9%). No AZFa deletion was detected in any of the patients. No chromosomal abnormality and Y chromosome microdeletion was detected in control group. The prevalence of chromosomal abnormalities and Y chromosome microdeletions shows the importance of genetic factors in male infertility. The analysis of karyotype and Y microdeletions in infertile men provide a proper understanding about the causes of infertility, the choice of the appropriate assisted reproduction technique and reducing the risk of transmission of these genetic defects to the future generation.

Y-chromosome microdeletions are not associated with SHOX haploinsufficiency

studyquestion: Are Y-chromosome microdeletions associated with SHOX haploinsufficiency, thus representing a risk of skeletal anom- alies for the carriers and their male descendents? summaryanswer: The present study shows that SHOX haploinsufficiency is unlikely to be associated with Y-chromosome microdele- tions. what is known already: Y-chromosome microdeletions are not commonly known as a major molecular genetic cause of any patho- logical condition except spermatogenic failure. However, it has been recently proposed that they are associated not only with infertility but also with anomalies in the pseudoautosomal regions (PAR), among which SHOX haploinsufficiency stands out with a frequency of 5.4% in microdele- tion carriers bearing a normal karyotype. This finding implies that sons fathered by men with Y-chromosome defects will not only exhibit fertility problems, but might also suffer from SHOX-related conditions. study design: Five European laboratories (Florence, Munster, Barcelona, Padova and Ancona), routinely performing Y-chromosome microdeletion screening, were enrolled in a multicenter study. participants/materials, setting, methods: PAR-linked and SHOX copy number variations (CNVs) were analyzed in 224 patients carrying Y-chromosome microdeletions and 112 controls with an intact Y chromosome, using customized X-chromosome-specific array-CGH platforms and/or qPCR assays for SHOX and SRY genes. main results and the role of chance: Our data show that 220 out of 224 (98.2%) microdeletion carriers had a normal SHOX copy number, as did all the controls. No SHOX deletions were found in any of the examined subjects (patients as well as controls), thus excluding an association with SHOX haploinsufficiency. SHOX duplications were detected in 1.78% of patients (n ¼ 4), of whom two had an abnormal and two a normal karyotype. This might suggest that Y-chromosome microdeletions have a higher incidence for SHOX duplications, irrespective of the patient's karyotype. However, the only clinical condition observed in our four SHOX-duplicated patients was infertility. limitations, reasons for caution: The number of controls analyzed is rather low to assess whether the SHOX duplications found in the two men with Y-chromosome microdeletions and a normal karyotype represent a neutral polymorphism or are actually associated with the presence of the microdeletion. wider implications of the findings: Men suffering from infertility due to the presence of Y-chromosome microdeletions can resort to artificial reproductive technology (ART) to father their biological children. However, infertile couples must be aware of the risks implied and this makes genetic counseling a crucial step in the patient's management. This study does not confirm previous alarming data that showed an association between Y-chromosome microdeletions and SHOX haploinsufficiency. Our results imply that deletion carriers have no augmented

INCIDENCE OF MICRODELETIONS IN THE AZF REGION OF THE Y CHROMOSOME IN SLOVAK PATIENTS WITH AZOOSPERMIA

The Y chromosome accumulates male-related genes including sex-determining region of Y-chromosome (SRY) and several spermatogenesis-related genes. The long arm contains azoospermia factor (AZF) region (including sub-regions AZFa, AZFb and AZFc). Microdeletions in this region are responsible for azoospermia and oligospermia and result in the male infertility. The aim of this study was to analyze incidence of microdeletions in the AZF region of Y chromosome in patients with azoospermia from Slovakia. Over the period from 2005 to 2009 a total of 239 men (mean age 31.74 years) were analyzed. The diagnosis of azoospermia was established on the basis of semen analysis. All patient samples were analyzed cytogenetically. Chromosomal analysis was performed on all patients on cultured lymphocytes from peripheral blood. For exact diagnosis of microdeletions in AZF region we used a PCR-method using a set of sequence-tagged sites from all AZF sub-regions (according to the recommendation by the European Academy of Andrology and the European Quality Monitoring Network Group). Among our 226 patients with azoospermia and with normal karyotype, 8 patients (mean age 30.6 years) had microdeletions in the AZF region of the Y chromosome (3.35%). Considering particular types of deletions we determined deletions in each region AZFa,b,c but also a complete deletion of the entire AZF region. The presence of microdeletion(s) in the AZFc region was the most frequent. In our study we found 12 patients (5%) with 47,XXY karyotype (Klinefelter syndrome), but these patients didn't have microdeletion of Y chromosomes. The study confirmed that percentage of microdeletions in the AZF region is low in Slovak azoospermic patients, but important from a prognostic view.

Fluorescence in situ hibridization (FISH) studies in carriers of microdeletions in the Y-chromosome

OBJECTIVE: To assess the incidence of chromosomal abnormalities in embryos and spermatozoa from patients with microdeletions in the SRY and AZF regions of the Y chromosome. DESIGN: Retrospective study. MATERIALS AND METHODS: A total of 24 couples diagnosed as severe male factor infertility were included. All of them had normal karyotype and they were checked for microdeletions in the SRY, AZF regions of the Y chromosome. Five of them showed microdeletions, whereas in the remaining 19 no microdeletions were found. FISH analysis for chromosomes 13, 18, 21, X and Y were performed in sperm samples from 8 patients. All couples underwent a Preimplantation Genetic Diagnosis cycle for Aneuploidy Screening (PGD-AS). Embryo biopsy was performed on day-3 and chromosomes 13, 15, 16, 18, 21, 22, X and Y were analysed. PGD-AS results were compared between two groups of patients, with and without Y-microdeletions and a control group of fertile patients undergoing PGD due to sex-linked diseases. RESULTS: In the group of patients with Y-microdeletions, the percentage of cycles with embryo transfer and blastocyst rates were half than in patients without Y-microdeletions and the control group. Five out of seven patients without Y-microdeletions had abnormal FISH results in sperm. Only one patient with Y-microdeletions had a FISH study in sperm and was extremely abnormal with 29.8% of aneuploidies for the sex chromosomes. In this patient four out of six embryos analysed displayed sex chromosome abnormalities.Tabled 1Patients without Y-microdeletionsPatients with Y-microdeletionsControlsMean age (SD)34.2 (2.2)32.4 (1.2)33.0 (2.4)No. of cycles19533% Cycles with transfer79.040.087.5% Pregnancies53.310042.9Implantation rate45.850.034.4% Miscarriages12.50.016.7No. of analysed embryos7817200% Abnormal embryos61.5aStatistical differences with control group. P<0.05.70.6aStatistical differences with control group. P<0.05.34.0Blastocyst rate66.7bStatistical differences between the two groups of patients. P<0.05.35.3bStatistical differences between the two groups of patients. P<0.05.50.25% Sex chromosome abnormalities17.3aStatistical differences with control group. P<0.05.bStatistical differences between the two groups of patients. P<0.05.41.2aStatistical differences with control group. P<0.05.bStatistical differences between the two groups of patients. P<0.05.7.5a Statistical differences with control group. P<0.05.b Statistical differences between the two groups of patients. P<0.05. Open table in a new tab CONCLUSIONS: Patients with severe male factor infertility have an increased risk of chromosomally abnormal embryos. In the patients with Y-microdeletions this increase was more remarkable, mostly for sex chromosomes. The presence of microdeletions in the Y chromosome could have an effect in male meiosis, as can be deduced from the fact that in one of these patients an extremely high incidence of aneuploidies for the sex chromosomes was observed.

A reinvestigation of non-disjunction resulting in 47, XXY males of paternal origin

We have used polymorphisms within the Xp/Yp pseudoautosomal region (PAR 1) to determine the frequency and location of recombination in 80 paternally derived 47, XXY males. Of 64 informative results, there were 10 single cross-overs, one double cross-over and 53 without a cross-over. Therefore 2/3 of 47, XXY males of paternal origin result from meiosis in which the X and Y chromosomes fail to recombine. This failure was not associated with the presence of an increase in recombination in the smaller Xq/Yq pseudoautosomal region (PAR 2) or with the presence of microdeletions within PAR 1.

Use of fluorescence in situ hybridization (FISH) in the diagnosis of DiGeorge sequence and related diseases.

The proximal portion of human chromosome 22q has been implicated in the pathogenesis of a clinically diverse group of conditions including DiGeorge sequence (DGS), velocardiofacial syndrome, and CHARGE association as well as isolated conotruncal heart anomalies. Frequently, overlap in the clinical presentation of these syndromes occurs and, recently, the presence of microdeletions on chromosome 22q11.2 with varying frequencies has been demonstrated in these syndromes. Using fluorescence in situ hybridization (FISH), we assessed 20 consecutive patients who were cytogenetically and clinically evaluated for a suspected syndrome that could be due to a microdeletion of chromosome 22q11.2. After cytogenetic testing and full clinical evaluation, we compared the results by FISH with the final clinical diagnosis and karyotype results. We found that microdeletions of 22q11.2 were detected in three of the five patients who were evaluated for DGS. The three cases with microdeletions appeared clinically to have DGS while the two negative cases were more atypical. High-resolution banding techniques did not detect a microdeletion in any of the cases; however, one of the 20 patients had a translocation between chromosomes 13 and 22. This patient also had a microdeletion of 22q11.2 detected by FISH and clinical features of DGS. None of the patients who were evaluated for disorders related to DGS showed microdeletions. We conclude that FISH is a useful, easily applied technique for the diagnosis of 22q11.2 microdeletion syndromes, particularly DGS. This test may also be useful in genetic counseling and in both prenatal and postnatal diagnoses.

Cardiovascular molecular genetics.

This monograph reviews advances in understanding the genetic basis of heritable disorders of the heart and vasculature, including hypertrophic cardiomyopathy, Marfan syndrome, conotruncal malformations, atrioventricular septal defects, supravalvular aortic stenosis, and the field defects associated with DiGeorge and velocardiofacial syndromes. The prognostic value and the functional effects of beta myosin heavy chain gene mutations in familial hypertrophic cardiomyopathy are discussed. The relation between Marfan syndrome and fibrillin mutations and that between supravalvular aortic stenosis and William syndromes and elastin mutations are reviewed, as is the presence of microdeletions in 22q11 in DiGeorge syndrome, velocardiofacial syndrome, and nonsyndromic patients with conotruncal malformations. The relation between neural crest cells and field defects are considered in the context of the genetic basis of Patch, a mutation that results in abnormal neural crest cell migration and conotruncal malformations. The role of transforming growth factor beta isoforms in cardiac morphogenesis is considered in the light of apparently normal morphogenesis in transforming growth factor beta 1 null mice.