ABSTRACT
OBJECTIVE: To present the results of molecular genetics analysis in men with reproductive disorders focusing on the DNA segments and genes which affect spermatogenesis. DESIGN: Original article. SETTING: Institute of Biology and Medical Genetics of the First Faculty of Medicine and General Teaching Hospital, Prague. METHODS: One hundred and twenty-three patients identified with a fertility disorder were screened for mutations of the CFTR gene. In all patients were performed cytogenic analysis and assessment of Y-chromosome microdeletions. In 107 patients where the fertility was not detected by routine examination we performed an analysis for X-chromosome microdeletions (CNV64, CNV67, CNV69) and in certain genes necessary for normal spermatogenesis (AGFG1, CAPZA3, CNTROB, HOOK1, GOPC, SPATA16). RESULTS: Our results did not reveal any negative efffects of X-chromosome microdeletion on spermatogenesis. Analysis of six genes showed in two patients in gene SPATA16 a homozygotic haplotype [1526C>T + 1577T>C] which can be most probably responsible for the fertility in two examined patients. CONCLUSION: According to our results we do not recommend introduction of X-chromosome microdeletions assays in areas CNV64 , CNV67 and CNV69 into routine diagnostic. Regarding the selected genes affecting spermatogenesis, our results showed that homozygotic haplotype [ 1526C>T + 1577T>C] in SPATA16 gene is very likely responsible for infertility in two of our patients. The above mentioned haplotype deserves attention in the investigation of male infertility.
Subject(s)
Infertility, Male/etiology , Spermatogenesis/genetics , Haplotypes , Homeodomain Proteins/genetics , Humans , Male , Vesicular Transport ProteinsABSTRACT
Pericentric inversion of human chromosome 9 [inv(9)] is a relatively common cytogenetic finding. It is largely considered a clinically insignificant variant of the normal human karyotype. However, numerous studies have suggested its possible association with certain pathologies, e.g., infertility, habitual abortions or schizophrenia. We analysed the incidence of inv(9) and the spectrum of clinical indications for karyotyping among inv(9) carriers in three medical genetics departments in Prague. In their cytogenetic databases, among 26,597 total records we identified 421 (1.6 %) cases of inv(9) without any concurrent cytogenetic pathology. This study represents the world's largest epidemiological study on inv(9) to date. The incidence of inv(9) calculated in this way from diagnostic laboratory data does not differ from the incidence of inv(9) in three specific populationbased samples of healthy individuals (N = 4,166) karyotyped for preventive (amniocentesis for advanced maternal age, gamete donation) or legal reasons (children awaiting adoption). The most frequent clinical indication in inv(9) carriers was "idiopathic reproductive failure" - 37.1 %. The spectra and percentages of indications in individuals with inv(9) were further statistically evaluated for one of the departments (N = 170) by comparing individuals with inv(9) to a control group of 661 individuals with normal karyotypes without this inversion. The proportion of clinical referrals for "idiopathic reproductive failure" among inv(9) cases remains higher than in controls, but the difference is not statistically significant for both genders combined. Analysis in separated genders showed that the incidence of "idiopathic reproductive failure" could differ among inv(9) female and male carriers.
Subject(s)
Chromosome Inversion/genetics , Chromosomes, Human, Pair 9/genetics , Adolescent , Child , Cytogenetics , Female , Humans , Karyotyping , MaleABSTRACT
The aim of the study was to analyze frequency of SHOX gene defects and selected dysmorphic signs in patients of both idiopathic short stature (ISS) and Léri-Weill dyschondrosteosis (LWD), all derived from the Czech population. Overall, 98 subjects were analyzed in the study. Inclusion criteria were the presence of short stature (-2.0 SD), in combination with at least one of the selected dysmorphic signs for the ISS+ group; and the presence of Madelung deformity, without positive karyotyping for the LWD+ group. Each proband was analyzed by use of P018 MLPA kit, which covers SHOX and its regulatory sequences. Additionally, mutational analysis was done of the coding portions of the SHOX. Both extent and breakpoint localizations in the deletions/duplications found were quite variable. Some PAR1 rearrangements were detected, without obvious phenotypic association. In the ISS+ group, MLPA analysis detected four PAR1 deletions associated with a SHOX gene defect, PAR1 duplication with an ambiguous effect, and two SHOX mutations (13.7%). In the LWD+ group, MLPA analysis detected nine deletions in PAR1 region, with a deleterious effect on SHOX, first reported case of isolated SHOX enhancer duplication, and SHOX mutation (68.8%). In both ISS+ and LWD+ groups were positivity associated with a disproportionately short stature; in the ISS+ group, in combination with muscular hypertrophy. It seems that small PAR1 rearrangements might be quite frequent in the population. Our study suggests disproportionateness, especially in combination with muscular hypertrophy, as relevant indicators of ISS to be the effect of SHOX defect.
Subject(s)
Growth Disorders/diagnosis , Growth Disorders/genetics , Homeodomain Proteins/cerebrospinal fluid , Homeodomain Proteins/genetics , Mutation , Osteochondrodysplasias/genetics , Adolescent , Adult , Child , Child, Preschool , DNA Copy Number Variations , Female , Humans , Male , Muscular Atrophy/genetics , Osteochondrodysplasias/diagnosis , Short Stature Homeobox ProteinABSTRACT
OBJECTIVES: SNP array (array method using Single Nucleotide Polymorphisms) enables to detect cytogenetically undetectable submicroscopic alterations (microdeletions, microduplications), which could be also causative for ultrasonographic anomalies of fetus. This article describes the principle, advantages, disadvantages and application possibilities of the SNP array method in prenatal diagnosis. The ten month experience with SNP array use in prenatal diagnosis is presented. DESIGN: Prospective study. SETTINGS: Gennet, Prague. MATERIAL AND METHODS: During the period from April 2010 to January 2011 we performed 110 SNP array analyses of fetal DNA: 14 chorionic villi samples (CVS), 88 amniotic fluid samples (AMC), 1 cord blood sample and 7 miscarriage samples. Laboratory tests were carried out on DNA from both cultured and uncultured fetal cells. Examinations were performed in fetuses with sonographic abnormal findings having normal karyotype. In addition 14 fetal cytogenetic abnormalities were solved. SNP array analysis was performed using Illumina InfiniumHD HumanCytoSNP-12 chip. All data were analysed by Illumina KaryoStudio and GenomeStudio software. RESULTS: SNP array analysis was performed in 108 fetuses (only 2 examination failures, 1.8%). In total, we detected CNV (copy number variation) in 29 samples (29/108 = 27%). 15% (16/108) of fetuses with abnormal ultrasound findings were found to carry clinically relevant CNV. Probably benign CNVs were found in 8 samples (8/108 = 7%) and in additional 5 CNVs parental samples have not been analysed yet. Excluding karyotypically abnormal cases clinically relevant CNVs were found in 10% of fetuses (9/94). In all cases with de novo chromosomal aberration the clinical relevancy was clarified (imbalances in 50%). CONCLUSION: Our data suggest that SNP array analysis is a relevant and useful technique in prenatal diagnosis.
Subject(s)
Congenital Abnormalities/diagnosis , Oligonucleotide Array Sequence Analysis , Polymorphism, Single Nucleotide , Prenatal Diagnosis , Congenital Abnormalities/diagnostic imaging , Congenital Abnormalities/genetics , Female , Humans , Pregnancy , Ultrasonography, PrenatalABSTRACT
AIM OF STUDY: Analysis of incidence of chromosomal abnormalities and variants in foetuses karyotyped because of the advanced maternal age. TYPE OF STUDY: A retrospective epidemiological study of results of cytogenetic examinations followed amniocentesis in 418 foetuses. MATERIAL AND METHODS: In our study we have used data from archives of the Cytogenetic laboratory of the Institute of Biology and Medical Genetics of the First Faculty of Medicine, Charles University and General Teaching Hospital in Prague. We have included only the cases where the amniocentesis was performed solely because of advanced maternal age. All cases were divided in specific groups and analyzed. RESULTS: There were totally 1107 karyotype examinations following the amniocentesis between 2007 and 2009 in our laboratory. Among these cases, 418 amniocenteses (37.8%) were performed only because of the advanced maternal age. The mean maternal age in this group was 38.02 +/- 2.4 years. In the whole group of 418 foetuses, 256 of them (61.24%) had normal karyotype, without chromosomal variants or pathologies. In 9 cases (2.15%) we identified pathologic karyotype. Down syndrome was identified in 3 cases (0.72%), what means one case of Down syndrome per 139 amniocenteses performed because of the advanced maternal age. Among other pathologies there were three (0.72%) gonosomal aneuploidies. Variants of acrocentric chromosomes were identified in 121 (28.95%) foetuses, variants of heterochromatine regions in 53 (12.68%) foetuses and other karyotype variants in one case (0.24%). In some cases, we have identified coincidence of more than one chromosomal variant and/or pathology. CONCLUSION: Our study presents the overview of chromosomal pathologies and variants that can be identified in fetal karyotype examinations because of the advanced maternal age. The efficiency of Down syndrome identification did not differ from the overall efficiency of amniocentesis in the Czech Republic. Advanced maternal age is still considered as an important part of the indication criteria for invasive prenatal diagnosis.
