Genetic diagnosis of Rubinstein-Taybi Syndrome with Multiplex Ligation-dependent Probe Amplification (MLPA) and Whole Exome Sequencing (WES): A Case Series with 3 Novel CREBBP Variants
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PROVIDER: PRJEB49962 | ENA |
REPOSITORIES: ENA
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Project description:Rubinstein-Taybi Syndrome (RSTS) is a rare congenital disease with distinctive facial features, broadening of the thumbs and halluces, and developmental delay. RSTS is caused by de novo genetic alterations in CREBBP and the homologous EP300 genes. In this study, we established a genetic diagnostic protocol by integrating multiplex ligation-dependent probe amplification (MLPA) and whole-exome sequencing (WES). Five patients clinically diagnosed with RSTS were enrolled for genetic testing. Germline DNA was extracted from the peripheral blood of the patients and their families. One patient (case 1) was identified as harboring a large heterozygous deletion in the 16p13.3 region, spanning the CREBBP gene. Three patients (Cases 2-4) harbored different CREBBP variants (c.2608C>T:p.Gln870Ter,c.4404_4405del:p.Thr1468fs,c.3649C>T:p.Gln1217Ter). No causative variants were identified for the fifth RSTS patient (case 5). Here, we propose a molecular diagnostic protocol that identified causative genetic alterations in 4/5 of the patients, yielding a molecular diagnostic rate of 80%. Given the rarity of RSTS, more research is needed to explore its pathogenesis and mechanism.
| S-EPMC9024331 | biostudies-literature
Project description:Mutations in the PAX6 gene have been implicated in aniridia, a congenital malformation of the eye with severe hypoplasia of the iris. However, not all aniridia cases can be explained by mutations in the PAX6 gene. The purpose of this study was to enhance the molecular diagnosis of aniridia using multiplex ligation-dependent probe amplification (MLPA). Total genomic DNA was isolated from peripheral blood of 70 unrelated probands affected with aniridia. Polymerase chain reaction (PCR) was performed followed by automated bidirectional sequencing. Additionally, MLPA was performed. We identified 24 different point mutations in the PAX6 gene in 34 patients after sequencing. In eight additional patients, we identified a deletion of one or more exons of the PAX6 gene or in the 3' regulatory region of the PAX6 gene using MLPA. This work demonstrates the necessity to screen for larger deletions in the region of the PAX6 gene in addition to the sequencing of exons in the PAX6 gene. The mutation detection rate will increase from 49% to 60%. This shows that MLPA substantially enhances the molecular diagnosis of aniridia.
| S-EPMC2375324 | biostudies-literature
Project description:BackgroundMultiplex ligation-dependent probe amplification (MLPA) was originally described as an efficient and reliable technique for gene dosage or DNA copy number variation (CNV) analysis. Due to its low cost, reliability, sensitivity, and relative simplicity, MLPA has rapidly gained acceptance in research and diagnostic laboratories, and fills the gap between genome-wide analysis and single gene analysis. A number of new applications have been developed shortly after the introduction of MLPA, including methylation-specific MLPA (MS-MLPA), the use of MLPA in SNP genotyping, copy number analysis in segmentally duplicated regions, etc. However, probe design is time consuming and error prone. Recently software has been developed to help human genomic MLPA probe selection and optimization. For other genomes and MS-MLPA, probe design remains a challenge.FindingsThis paper describes a number of new features added to the previous H-MAPD software, which include: 1) probe selection for MS-MLPA; 2) support of mouse and rat genomes; 3) a set of new stuffer sequences. In addition, a physical-chemical property verification tool was implemented to verify user defined probes.ConclusionsMAPD is a web-based tool which is freely available to non-commercial users. The previous H-MAPD software has been used by about 200 users from more than 30 countries. With the new features, the author hopes MAPD will bring more convenience to the MLPA community.
| S-EPMC2893534 | biostudies-literature
Project description:Gene amplification is an important mechanism for oncogene activation, a crucial step in carcinogenesis. Compared to female breast cancer, little is known on the genetic makeup of male breast cancer, because large series are lacking. Copy number changes of 21 breast cancer related genes were studied in 110 male breast cancers using multiplex ligation-dependent probe amplification. A ratio of >1.3 was regarded indicative for gene copy number gain and a ratio >2.0 for gene amplification. Data were correlated with clinicopathological features, prognosis and 17 genes were compared with a group of female breast cancers. Gene copy number gain of CCND1, TRAF4, CDC6 and MTDH was seen in >40 % of the male breast cancer cases, with also frequent amplification. The number of genes with copy number gain and several single genes were associated with high grade, but only CCND1 amplification was an independent predictor of adverse survival in Cox regression (p = 0.015; hazard ratio 3.0). In unsupervised hierarchical clustering a distinctive group of male breast cancer with poor prognosis (p = 0.009; hazard ratio 3.4) was identified, characterized by frequent CCND1, MTDH, CDC6, ADAM9, TRAF4 and MYC copy number gain. Compared to female breast cancers, EGFR (p = 0.005) and CCND1 (p = 0.041) copy number gain was more often seen in male breast cancer, while copy number gain of EMSY (p = 0.004) and CPD (p = 0.001) and amplification in general was less frequent. In conclusion, several female breast cancer genes also seem to be important in male breast carcinogenesis. However, there are also clear differences in copy number changes between male and female breast cancers, pointing toward differences in carcinogenesis between male and female breast cancer and emphasizing the importance of identifying biomarkers and therapeutic agents based on research in male breast cancer. In addition CCND1 amplification seems to be an independent prognosticator in male breast cancer.
| S-EPMC3413821 | biostudies-literature
Project description:Mutations in the ALDOB gene impair the activity of the hepatic aldolase B enzyme, causing hereditary fructose intolerance (HFI), an inherited autosomic recessive disease of carbohydrate metabolism, that can result in hypoglycemia, liver and kidney failure, coma, and death. Noninvasive diagnosis is possible by identifying mutant ALDOB alleles in suspected patients. We report the genetic characterization of a cohort of 18 HFI Caucasian patients, based on PCR-sequencing and Multiplex Ligation-dependent Probe Amplification (MLPA), with the identification of two novel genetic lesions: a small duplication c.940_941dupT (p.Trp314fsX22) and a large deletion encompassing the promoter region and exon 1. MLPA and long range-PCR (LR-PCR) also identified the recently reported g.7840_14288del6448 allele with a surprisingly high frequency (11%) within our patients' cohort. The most common p.Ala150Pro (44%), p.Ala175Asp (19%), p.Asn335Lys (8%), and/or the known c.360-363del4 (5%), p.Tyr204X (2.8%), IVS6 -2A>G (2.8%) mutant alleles were identified in 14 patients at a homozygous or compound-heterozygous level. The integration of PCR-sequencing analysis with exon-dosage tools [MLPA and quantitative fluorescent multiplex-PCR (QFM-PCR)] led to the full genotyping of patients within our cohort and to the identification of the new deletion encompassing the promoter region and exon 1.
| S-EPMC3565637 | biostudies-literature
Project description:PurposeTo assess the cost-effectiveness of Multiplex Ligation-dependent Probe Amplification (MLPA, P095 kit) compared to karyotyping.MethodsA cost-minimization analysis alongside a nationwide prospective clinical study of 4,585 women undergoing amniocentesis on behalf of their age (?36 years), an increased risk following first trimester prenatal screening or parental anxiety.ResultsDiagnostic accuracy of MLPA (P095 kit) was comparable to karyotyping (1.0 95% CI 0.999-1.0). Health-related quality of life did not differ between the strategies (summary physical health: mean difference 0.31, p = 0.82; summary mental health: mean difference 1.91, p = 0.22). Short-term costs were lower for MLPA: mean difference <euro>315.68 (bootstrap 95% CI <euro>315.63-315.74; -44.4%). The long-term costs were slightly higher for MLPA: mean difference <euro>76.42 (bootstrap 95% CI <euro>71.32-81.52; +8.6%). Total costs were on average <euro>240.13 (bootstrap 95% CI <euro>235.02-245.23; -14.9%) lower in favor of MLPA. Cost differences were sensitive to proportion of terminated pregnancies, sample throughput, individual choice and performance of tests in one laboratory, but not to failure rate or the exclusion of polluted samples.ConclusionFrom an economic perspective, MLPA is the preferred prenatal diagnostic strategy in women who undergo amniocentesis on behalf of their age, following prenatal screening or parental anxiety.
| S-EPMC3249153 | biostudies-literature
Project description:Fanconi anemia (FA) is a rare inherited disease characterized by developmental defects, short stature, bone marrow failure, and a high risk of malignancies. FA is heterogeneous: 15 genetic subtypes have been distinguished so far. A clinical diagnosis of FA needs to be confirmed by testing cells for sensitivity to cross-linking agents in a chromosomal breakage test. As a second step, DNA testing can be employed to elucidate the genetic subtype of the patient and to identify the familial mutations. This knowledge allows preimplantation genetic diagnosis (PGD) and enables prenatal DNA testing in future pregnancies. Although simultaneous testing of all FA genes by next generation sequencing will be possible in the near future, this technique will not be available immediately for all laboratories. In addition, in populations with strong founder mutations, a limited test using Sanger sequencing and MLPA will be a cost-effective alternative. We describe a strategy and optimized conditions for the screening of FANCA, FANCB, FANCC, FANCE, FANCF, and FANCG and present the results obtained in a cohort of 54 patients referred to our diagnostic service since 2008. In addition, the follow up with respect to genetic counseling and carrier screening in the families is discussed.
| S-EPMC3388349 | biostudies-literature
Project description:BackgroundThe aims of this study were to evaluate the clinical utility of multiplex ligation-dependent probe amplification (MLPA) and array comparative genomic hybridization (aCGH) analyses on prenatal cases and to review prenatal ultrasound findings of cytogenomic syndromes.ResultsOf the 54 prenatal cases analyzed, cytogenomic abnormalities were characterized in 14 cases. In four fetuses with abnormal ultrasound findings, a 40.701 Mb duplication of 8q22.3-q24.3 and a 23.839 Mb deletion of 7q33-q36.3 derived from a paternal balanced translocation, a de novo 13.062 Mb deletion of 11q24.1-q25 for Jacobsen syndrome, a de novo 19.971 Mb deletion of 7q11.23-q21.3 for type 1 split-hand/foot malformation (SHFM1), and a de novo 28.909 Mb duplication of 3q21.1-q25.1 were detected. A 699.8 Kb deletion at 5p15.33 for Cri du Chat syndrome was confirmed in a fetus with abnormal MLPA result. A fetus with abnormal maternal screening was detected with a de novo distal 1.747 Mb duplication at 2q37.1-q37.2 and a 6.664 Mb deletion at 2q37.2-q37.3. Of the eight cases referred by history of spontaneous abortions, derivative chromosomes 11 from paternal carriers of a balanced 8q/11q and a 10q/11q translocation were noted in two cases, simple aneuploids of trisomy 2 and trisomy 21 were seen in three cases, and compound aneuploids of two or three chromosomes were found in three cases. Post-test genetic counseling was performed with detailed genomic information and well characterized postnatal syndromic features.ConclusionsThese results demonstrated that coupling MLPA screening and aCGH analysis are a cost-effective approach to detect cytogenomic abnormalities in a prenatal setting. The aCGH analysis provided not only genomic maps of breakpoints and gene content of imbalanced regions but also better inference of related phenotypes for genetic counseling. Prenatal ultrasound findings reported in the literature for Jacobsen syndrome, SHFM and Cri du Chat syndrome were summarized for use as diagnostic references.
| S-EPMC4271441 | biostudies-literature
Project description:Multiplex ligation-dependent probe amplification (MLPA) is a recently described method for detecting gross deletions or duplications of DNA sequences, aberrations which are commonly overlooked by standard diagnostic analysis. To determine the incidence of copy number variants in cancer predisposition genes from families in the Wessex region, we have analysed the hMLH1 and hMSH2 genes in patients with hereditary nonpolyposis colorectal cancer (HNPCC), BRCA1 and BRCA2 in families with hereditary breast/ovarian cancer (BRCA) and APC in patients with familial adenomatous polyposis coli (FAP). Hereditary nonpolyposis colorectal cancer (n=162) and FAP (n=74) probands were fully screened for small mutations, and cases for which no causative abnormality were found (HNPCC, n=122; FAP, n=24) were screened by MLPA. Complete or partial gene deletions were identified in seven cases for hMSH2 (5.7% of mutation-negative HNPCC; 4.3% of all HNPCC), no cases for hMLH1 and six cases for APC (25% of mutation negative FAP; 8% of all FAP). For BRCA1 and BRCA2, a partial mutation screen was performed and 136 mutation-negative cases were selected for MLPA. Five deletions and one duplication were found for BRCA1 (4.4% of mutation-negative BRCA cases) and one deletion for BRCA2 (0.7% of mutation-negative BRCA cases). Cost analysis indicates it is marginally more cost effective to perform MLPA prior to point mutation screening, but the main advantage gained by prescreening is a greatly reduced reporting time for the patients who are positive. These data demonstrate that dosage analysis is an essential component of genetic screening for cancer predisposition genes.
| S-EPMC2747696 | biostudies-other