Background: SHOX mutations have previously been described as causes of Léri-Weill dyschondrosteosis (LWD), Langer mesomelic dysplasia (LMD), and idiopathic short stature. The loss of X chromosome-Turner syndrome or mosaic 45,X/46,XX or 46,XY-also leads to the heterozygous loss of SHOX in patients with short stature only or with features similar to LWD. The aim of this study was to assess the efficacy of the targeted screening for SHOX variants, which involved different methods in the laboratory analysis of short stature. We determined the significance and positive predictive value of short stature for the detection of SHOX variants. Methods: Targeted screening for variants in SHOX involving MLPA, sequencing, karyotyping and FISH was performed in the short stature cohort (N = 174) and control cohort (N = 91). The significance of short stature and particular characteristics for the detection of SHOX variants was determined by Fisher's exact test, and the probability of SHOX mutation occurrence was calculated using a forward/stepwise logistic regression model. Results: In total, 27 and 15 variants influencing SHOX were detected in the short stature and control cohorts, respectively (p > 0.01). Sex chromosome aberrations and pathogenic CNV resulting in diagnosis were detected in eight (4.6%) and five (2.9%) patients of the short stature group and three (3.3%) and one (1.1%) individuals of the control group. VUS variants were discovered in 14 (8.0%) and 11 (12.1%) individuals of the short stature and control groups, respectively. MLPA demonstrated the detection rate of 13.22%, and it can be used as a frontline method for detection of aberrations involving SHOX. However, only mosaicism of monosomy X with a higher frequency of monosomic cells could be reliably discovered by this method. Karyotyping and FISH can compensate for this limitation; their detection rates in short stature group were 3.55% and 13.46% (N = 52), respectively. FISH proved to be more effective than karyotyping in the study as it could reveal cryptic mosaics in some cases where karyotyping initially failed to detect such a clone. We suggest adding FISH on different tissue than peripheral blood to verify sex-chromosome constitution, especially in cases with karyotypes: 45,X; mosaic 45,X/46,XX or 46,XY; 46,Xidic(Y) detected from blood; in children, where mosaic 45,X was detected prenatally but was not confirmed from peripheral blood. The correlation of short stature with the occurrence of SHOX mutations was insignificant and short stature demonstrates a low positive predictive value-15.5% as unique indicator for SHOX mutations. The typical skeletal signs of LWD, including Madelung deformity and disproportionate growth, positively correlate with the findings of pathogenic SHOX variants (p < 0.01) by Fisher's exact test but not with the findings of VUS variants in SHOX which are more prevalent in the individuals with idiopathic short stature or in the individuals with normal height.
- Publikační typ
- časopisecké články MeSH
Background: Autism spectrum disorder (ASD) is a complex heterogeneous developmental disease with a significant genetic background that is frequently caused by rare copy number variants (CNVs). Microarray-based whole-genome approaches for CNV detection are widely accepted. However, the clinical significance of most CNV is poorly understood, so results obtained using such methods are sometimes ambiguous. We therefore evaluated a targeted approach based on multiplex ligation-dependent probe amplification (MLPA) using selected probemixes to detect clinically relevant variants for diagnostic testing of ASD patients. We compare the reliability and efficiency of this test to those of chromosomal microarray analysis (CMA) and other tests available to our laboratory. In addition, we identify new candidate genes for ASD identified in a cohort of ASD-diagnosed patients. Method: We describe the use of MLPA, CMA, and karyotyping to detect CNV in 92 ASD patients and evaluate their clinical significance. Result: Pathogenic and likely pathogenic mutations were identified by CMA in eight (8.07% of the studied cohort) and 12 (13.04%) ASD patients, respectively, and in eight (8.07%) and four (4.35%) patients, respectively, by MLPA. The detected mutations include the 22q13.3 deletion, which was attributed to ring chromosome 22 formation based on karyotyping. CMA revealed a total of 91 rare CNV in 55 patients: eight pathogenic, 15 designated variants of unknown significance (VOUS)-likely pathogenic, 10 VOUS-uncertain, and 58 VOUS-likely benign or benign. MLPA revealed 18 CNV in 18 individuals: eight pathogenic, four designated as VOUS-likely pathogenic, and six designated as VOUS-likely benign/benign. Rare CNVs were detected in 17 (58.62%) out of 29 females and 38 (60.32%) out of 63 males in the cohort. Two genes, DOCK8 and PARK2, were found to be overlapped by CNV designated pathogenic, VOUS-likely pathogenic, or VOUS-uncertain in multiple patients. Moreover, the studied ASD cohort exhibited significant (p < 0.05) enrichment of duplications encompassing DOCK8. Conclusion: Multiplex ligation-dependent probe amplification and CMA yielded concordant results for 12 patients bearing CNV designated pathogenic or VOUS-likely pathogenic. Unambiguous diagnoses were achieved for eight patients (corresponding to 8.7% of the total studied population) by both MLPA and CMA, for one (1.09%) patient by karyotyping, and for one (1.09%) patient by FRAXA testing. MLPA and CMA thus achieved identical reliability with respect to clinically relevant findings. As such, MLPA could be useful as a fast and inexpensive test in patients with syndromic autism. The detection rate of potentially pathogenic variants (VOUS-likely pathogenic) achieved by CMA was higher than that for MLPA (13.04% vs. 4.35%). However, there was no corresponding difference in the rate of unambiguous diagnoses of ASD patients. In addition, the results obtained suggest that DOCK8 may play a role in the etiology of ASD.
- Publikační typ
- časopisecké články MeSH
Background: Interstitial microdeletion 14q22q23 is a rare chromosomal syndrome associated with variable defects: microphthalmia/anophthalmia, pituitary anomalies, polydactyly/syndactyly of hands and feet, micrognathia/retrognathia. The reports of the microdeletion 14q22q23 detected in the prenatal stages are limited and the range of clinical features reveals a quite high variability. Case presentation: We report a detection of the microdeletion 14q22.1q23.1 spanning 7,7 Mb and involving the genesBMP4andOTX2in the foetus by multiplex ligation-dependent probe amplification (MLPA) and verified by microarray subsequently. The pregnancy was referred to the genetic counselling for abnormal facial profile observed in the first trimester ultrasound scan and micrognathia (suspicion of Pierre Robin sequence), hypoplasia nasal bone and polydactyly in the second trimester ultrasound scan. The pregnancy was terminated on request of the parents. Conclusion: An abnormal facial profile detected on prenatal scan can provide a clue to the presence of rare chromosomal abnormalities in the first trimester of pregnancy despite the normal result of the first trimester screening test. The patients should be provided with genetic counselling. Usage of quick and sensitive methods (MLPA, microarray) is preferable for discovering a causal aberration because some of the CNVs cannot be detected with conventional karyotyping in these cases.To the best of our knowledge, this is the earliest detection of this microdeletion (occurred de novo), the first case detected by MLPA and confirmed by microarray. Literature review of the genotype-phenotype correlation in similar reports leads us to the conclusion that dosage imbalance of the chromosomal segment 14q22q23 (especially haploinsuffiency of the genesBMP4andOTX2) contributes significantly to orofacial abnormalities. Association of the region with the Pierre Robin sequence appears to be plausible.
- Publikační typ
- časopisecké články MeSH
AIMS: Trisomy of chromosome 21 is associated with Down syndrome (DS) - the commonest genetic cause of mental retardation. We report two unusual cases with partial trisomy of chromosome 21 and tetrasomy of chromosome 21 without DS phenotype. We include a short overview of the genotype-phenotype correlation studies in discussion. METHODS: Conventional chromosomal analysis, fluorescent in situ hybridisation (FISH), quantitative fluorescent PCR (QFPCR) and Nimblegen targeted chromosome 21 array were used for deciphering the genotypes. RESULTS: Conventional chromosomal analysis revealed one extra copy of derivative chromosome 21 in peripheral blood lymphocytes of the patients. FISH and QF PCR analyses identified duplicated loci (D21Z1, D21S1414, D21S1435) spanning from the centromere to band 21q21. Nimblegen targeted chromosome 21 array specified the range of duplication from the centromere to the band 21q21.3 (19 Mb) in the first case and the range of duplication and triplication resp from centromere to the bands 21q21.3 (15 Mb) and 21q11.2 (4 Mb) resp. in the second case. Additional material was of maternal origin in both cases. The different mechanisms led to the formation of the particular chromosomal imbalances. CONCLUSION: These findings confirm the conclusion of nonpresence of DS when bands 21q22.2 and 21q22.3 (Down critical region) are not duplicated. The patients had nonspecific phenotypes although some of their features such as "sandal gaps", joint hyperlaxity, hypotonia and brachycephaly are present in patients with DS. Our observation can help to narrow the region responsible for DS and to map the loci accountable for minor features of DS.
- MeSH
- Downův syndrom genetika MeSH
- fenotyp MeSH
- genotyp MeSH
- karyotyp MeSH
- kojenec MeSH
- lidé MeSH
- lidské chromozomy, pár 21 * MeSH
- předškolní dítě MeSH
- tetrazomie * MeSH
- trizomie * MeSH
- Check Tag
- kojenec MeSH
- lidé MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
Molecular techniques focused on detection of common aneuploidies--FISH and QFPCR--provide a quick result in prenatal diagnosis. There is a trend to apply these rapid tests as 'stand-alone' tests which would lead to substantial economical savings. The purpose of the retrospective study is to determine the frequency of chromosomal aberrations (CA) which would be missed by this tool in particular indication groups--residual cytogenetic risk. DESIGN: Retrospective study. SETTING: Department of Medical Genetics and Foetal Medicine University Hospital Olomouc. METHOD: 5305 prenatal samples were examined and the frequency of QFPCR undetected CA (structural and rare aneuploidies) was observed. RESULTS: The residual risk in patients referred for abnormal results of current prenatal screening programs for Down syndrome or for maternal age, without any ultrasound (US) pathological findings, was 0.9%. It was 6.9% in the group where US pathological findings or family history of CA were present. CONCLUSION: The rapid test can replace karyotyping if there is a risk for CA based exclusively on abnormal results of current screening programes for Down syndrome or age related risk, providing that US is normal.
- Klíčová slova
- kvantitativní fluorescenční PCR (QFPCR), fluorescenční in situ hybridizace (FISH), prenatální cytogenetická analýza,
- MeSH
- chromozomální aberace MeSH
- hybridizace in situ fluorescenční MeSH
- karyotypizace MeSH
- lidé MeSH
- polymerázová řetězová reakce metody MeSH
- prenatální diagnóza MeSH
- těhotenství MeSH
- trizomie MeSH
- Check Tag
- lidé MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- MeSH
- dítě MeSH
- genetické testování metody využití MeSH
- hybridizace in situ fluorescenční metody využití MeSH
- izochromozomy genetika MeSH
- lidé MeSH
- lidské chromozomy, pár 11 genetika MeSH
- lidské chromozomy, pár 9 genetika MeSH
- mentální retardace etiologie genetika MeSH
- trizomie genetika MeSH
- vrozené, dědičné a novorozenecké nemoci a abnormality diagnóza genetika MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
- MeSH
- Angelmanův syndrom etiologie genetika patologie MeSH
- delece genu MeSH
- diagnostické techniky molekulární metody MeSH
- dítě MeSH
- dospělí MeSH
- finanční podpora výzkumu jako téma MeSH
- hybridizace in situ fluorescenční metody MeSH
- lidé MeSH
- metylace DNA MeSH
- mutace MeSH
- Praderův-Williho syndrom etiologie genetika patologie MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé MeSH
Cíl studie: Zjištění prevalence chromozomálních aberací u párů s nejasnou příčinou neplodnostipodstupujích program IVF (in vitro fertilizace).Typ studie: Cytogenetická a molekulární cytogenetická analýza lymfocytů periferní krve ve skupiněpacientů podstupujících IVF. Detekce chromozomálních aberací u plodů z IVF.Název a sídlo pracoviště: Ústav lékařské genetiky a fetální medicíny FN a LF Univerzity Palackého,Olomouc.Metodika: Kultivace lymfocytů periferní krve popř. kultivace buněk z plodové vody a jejich následnákaryotypizace. Využití fl uorescenční in situ hybridizace (FISH) při vyhodnocování zastoupeníaberantních klonů u mozaik.Výsledky: Ze souboru 638 pacientů podstupujících léčbu neplodnosti pro mužský či ženský faktormělo 595 pacientů normální karyotyp a u 43 (6,8 %) pacientů byla nalezena chromozomální odchylka.Bylo detekováno 9 (1,4 %) případů balancovaných translokací, 2 (0,31 %) případy inverze,2 (0,31 %) případy delece, 2 (0,31 %) případy marker chromozomů, 5 (0,78 %) případů aneuploidiegonozomů (47,XXY) a 23 (3,65 %) případů mozaicismu gonozomů, z toho 22 (3,5 %) případů minoritníhomozaicismu.V malém souboru gravidit z IVF (n = 60) vyšetřovaných z genetické indikace bylo zjištěno 15procentnízastoupení chromozomálních aberací u fetu.Závěr: Náš výzkum ukazuje, že poměrně značné procento neplodných párů je postiženo chromozomálníaberací u některého z dvojice partnerů. Zastoupení chromozomálních aberací bylo u ženvyšší z důvodu vyššího zastoupení minoritního mozaicismu gonozomů. Z práce vyplývá doporučeníprovést chromozomální vyšetření před programem IVF.
Objective: To determine the prevalence of chromosomal aberrations in infertile couples undergoingin vitro fertilization (IVF).Design: Cytogenetic analysis of peripheral blood lymphocytes in the group of patients undergoingIVF. Detection of chromosomal aberrations in the fetuses after IVF.Setting: Department of Medical Genetics and Fetal Medicine, Medical Faculty, Palacký Universityand the University Hospital, Olomouc.Methods: Cultivation of peripheral blood lymphocytes or fi broblasts of amniotic fl uid. Using fl uorescentin situ hybridization in cases of mosaicism.Results: Out of 638 patients undergoing treatment for male or female infertility, 595 had normalkaryotype and 43 (6.8%) had abnormal karyotype. There were detected 9 (1.4%) cases of balancedchromosomal rearrangements, 2 (0.31%) cases of deletion of Y chromosome, 2 (0.31%) cases of inversion,2 (0.31%) cases of marker chromosome, 5 (0.78%) cases of gonosomal aneuploidy (47,XXY)and 23 (3.65%) cases of gonosomal mosaicism – out of the 22 (3.5%) cases of low-level mosaicism.In the small group of pregnant patients after IVF investigated for the risk of genetic disordersincluded in our study (n=60) the frequency of chromosomal abnormalities was 9 (15%).Conclusions: Our data show that a high number of infertile couples is affected by chromosomalaberations which occur more frequently in females than in males. It is caused by high frequencyof low-level gonosomal mosaicism in the group of infertile women.Chromosomal analyses are highly recommended before each IVF procedure.
- MeSH
- chromozomální aberace MeSH
- cytogenetické vyšetření metody MeSH
- dospělí MeSH
- fertilizace in vitro MeSH
- finanční podpora výzkumu jako téma MeSH
- infertilita diagnóza genetika terapie MeSH
- lidé MeSH
- mozaicismus MeSH
- samovolný potrat MeSH
- výsledek těhotenství MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- přehledy MeSH
- srovnávací studie MeSH
