Balkan Journal of Medical Genetics最新文献

Clopidogrel, is a standard treatment in the prevention of major adverse cardiovascular events (MACE) in patients with coronary artery disease (CAD). Clopidogrel response is highly variable, mainly due to the presence of polymorphisms in the genes involved in drug metabolism. The aim of this study was to evaluate the association between the presence of the ABCB1 C3435T and CYP2C19*2 polymorphism and the clinical outcome in patients with CAD treated with clopidogrel. A total of 96 patients with CAD were included in the study. Genomic DNA from peripheral blood was extracted from all patients with standard phenol/chloroform protocol. The genotyping was performed by Real-Time PCR using TagMan assays. The frequency of the reduced-function allele, in both genes, was higher in patients with negative outcome (36.36% vs 21.15%). A negative clinical outcome and an increased risk for MACE was observed in patients with concomitant inheritance of the CYP2C19 *1/*2 and ABCB1 CT genotype vs patients with other genotypes (22.73% vs 9.62%; OR 3.455; 95% CI= [0.936-12.743], p=0.05722. A trend towards higher risk of MACE was also noted in carriers of the CYP2C19*1/*1 and ABCB1 CC/CT genotype. Our results support the data on the association of the CYP2C19 *2 alone, or in combination with the ABCB1 C polymorphism with the increased risk of MACE. The results also indicate that the presence of ABCB1 C343T polymorphism might be potentially considered as independent predictor of MACE in patients on clopidogrel. However, these results are preliminary and should be confirmed on a larger number of patients.

We present the findings of a Whole Exome Sequencing in a 2-year-old boy, conceived via In Vitro Fertilization with donor sperm, who suffers from an undiagnosed neurological syndrome. The following heterozygous variant in the EPHA4 gene was identified and classified as likely pathogenic: c.1655_1656, p.(Ser552CysfsTer23). Subsequent segregation analysis showed that the variant was not inherited from the mother and the sperm donor is not accessible for genetic testing. The presented results can further expand upon the genetic variants considered when diagnosing complex neurological syndromes and shows the importance of access to biological samples from donor banks in genetically ambiguous cases.

Background: Almost 50% of NSCLC patients who initially show a successful response to tyrosine kinase inhibitors targeted therapy (TKI therapy) eventually develop acquired EGFR T790M mutation. The T790M secondary mutation can cause resistance to the targeted therapy and disease relapse. Since this mutation can be present at very low frequencies in liquid biopsy samples, droplet digital PCR (ddPCR), due to its high sensitivity, has opened the possibility for minimally invasive monitoring of the disease during TKI targeted therapy.

Materials and methods: For this study, a total of 45 plasma samples from NSCLC patients with previously detected EGFR-activating mutations were analyzed. Extracted circulating free DNA was amplified and examined for the presence of T790M mutation using ddPCR technology. For the data analysis, QuantaSoft Software was used.

Results: Of 45 tested plasma samples, a total of 14 samples were identified as positive for the T790M mutation. The same samples eventually showed the presence of T790M mutation in FFPE. Droplet digital PCR showed its great advantage in high sensitivity detection of rare allele variants. Our ddPCR assay detected T790M mutant allele in frequencies from 0.1%. The average number of droplets generated by ddPCR was 9571.

Conclusion: Monitoring of the T790M mutation has an important role in the examination of the effects of the prescribed TKI therapy. Since monitoring of potential changes during TKI therapy requires repeated sampling, our results showed that ddPCR technology has made it possible to use liquid biopsy as an adequate minimally invasive alternative for single nucleotide polymorphisms (SNP) detection.

Raynaud-Claes syndrome is rare condition characterized with intellectual disability and is caused by X-linked pathogenic variants in CLCN4 gene. Hemizygous missense variant NM_001830.4: c.1597G>A (p.V533M) was detected in a 6-year-old male followed up with intellectual disability, dysmorphism, and epileptic encephalopathy. The mother and one sister of the patient were also carrying the same variant. The clinical picture of the patient was significantly more severe, and the patient exhibited nonconvulsive status. Tonic status was observed with benzodiazepine treatment and the patient was successfully treated with a ketogenic diet. Many types of seizures can be seen in Raynaud-Claes syndrome, some of which can be life-threatening. CLCN4 variants can be investigated in patients who exhibit an increase in tonic seizures with benzodiazepine treatment. However, ketogenic dietary therapy as first-line treatment can be lifesaving in resistant epilepsy cases caused by the CLCN4 gene.

Preimplantation genetic testing (PGT) is the earliest form of prenatal diagnosis that has become an established procedure for couples at risk of passing a severe genetic disease to their offspring. At UMC Ljubljana, we conducted a retrospective register-based study to present 15 years of PGT service within the public healthcare system in Slovenia. We collected the data of the PGT cycles from 2004 to 2019 and compared clinical outcomes for chromosomal and monogenic diseases using different embryo biopsy and testing approaches. In addition, we assessed the extent to which PGT has become the preferred option compared to classic prenatal diagnostics. We treated 211 couples, 110 with single gene disorder, 88 with structural chromosome rearrangement and 13 for numerical chromosome aberration. There were 375 PGT cycles with oocyte retrieval, while embryo transfer was possible in 263 cases resulting in 78 deliveries and 84 children. Altogether, the clinical pregnancy rate per embryo transfer was 31% in 2004-2016 (blastomere biopsy) and 43% in 2017-19 (blastocyst biopsy), respectively. We assessed that approximately a third of couples would opt for PGT, while the rest preferred natural conception with prenatal diagnosis. Our results show that providing a PGT service within the public healthcare system has become a considerable option in pregnancy planning for couples at risk of transmitting a severe genetic disease to their offspring. In Slovenia, approximately a third of couples would opt for PGT. Although the number of cycles is small, our clinical results are comparable to larger centres.

Chromosomal abnormalities are the most common causes of early pregnancy losses (EPLs). In this study, we aimed to evaluate the incidence and spectrum of chromosomal abnormalities in EPLs and correlate them with different clinical characteristics. We performed Quantitative Fluorescent PCR (QF-PCR), followed by subtelomeric Multiplex Ligation Probe Amplification (MLPA) analysis to detect chromosomal abnormalities in 900 products of conceptions (POCs) from EPLs collected over a period of 10 years. Chromosomal abnormalities were present in 56.25% of uncontaminated EPLs, with significantly higher incidence in women ≥36 years (71.37%, p<0.0001) in comparison to women ≤30 years of age (43.40%). Trisomies were also more common in women ≥36 years (79.68%, p<0.0001) than in those ≤30 years of age (48.70%). In contrast, triploidy and monosomies were more prevalent in women ≤30 years of age (26.09%, p<0.0001 and 16.52%, p=0.0066 respectively) than in women ≥36 years of age (6.42% and 6.42% respectively). Trisomy 16 was more common in women ≤30 (39.29%, p=0.0009) than in those ≥36 years of age (16.78%), while trisomy 22 was predominant among women ≥36 (23.49%, p=0.013), and was not present in the group of women ≤30 years of age. The frequency of chromosomal abnormalities in POCs from women with sporadic (61.19%) was higher than in those with recurrent EPLs (55.21%). This difference, however, was not statistically significant (p=0.164). Although some differences in the chromosomal aneuploidy rates among women with different ABO blood groups, as well as among 6-8 and 9-11 gestational week EPLs were observed, further larger studies are required to confirm these findings. In conclusion, our study enriches the knowledge about chromosomal abnormalities as a cause of EPLs and confirms the higher incidence of foetal chromosomal abnormalities in EPLs in women of older reproductive age. Furthermore, it shows that using QF-PCR and MLPA methodologies, a high detection rate of chromosomal abnormalities in EPLs can be reached.

Objectives: Polymorphisms of the uridine-diphospho-glucuronosyltransferase 1A1 (UGT1A1) gene, hepatic solute carrier organic anion transporter 1B1/B3 (SLCO1B1/3) gene, and glutathione S-transferase (GST) gene have been associated with significant hyperbilirubinemia in some populations. This study aims to determine whether the variation of UGT1A1, SLCO1B1/3 and GST genes play an important role in neonatal hyperbilirubinemia in Turkish newborn infants.

Methods: The study included 61 idiopathic hyperbilirubinemia cases, 28 prolonged jaundice cases, and 41 controls. Ten common polymorphisms in four genes involved in bilirubin metabolism were examined. Polymerase chain reaction-restriction fragment length polymorphism method was used to detect variants of those genes.

Results: No association was found between the variants of UGT1A1 at nt 211, the SLCO1B1 gene at nt 388, 463, 521, 1463, the SLCO1B3 gene at nt 334, 727+118, 1865+19721, and the GST gene at nt 313, 341, and neonatal hyperbilirubinemia. There was no difference between the case and control groups in terms of allele frequencies of these genes (except SLCO1B3 at nt 334) (p>0.05 in all comparisons). The presence of the G allele of the SLCO1B3 at nt 334 variant gene seemed to protect from jaundice in infants with idiopathic hyperbilirubinemia.

Conclusion: These gene polymorphisms currently studied do not seem to modulate the risk of hyperbilirubinemia in Turkish newborn infants.

Hypertension is a multifactorial chronic disease due to the interaction of environmental factors with genetic alteration. KLOTHO and ARNTL genes play an important role in the development of hypertension. Therefore, we analyzed the methylation status of KLOTHO and ARNTL genes by using methylation-sensitive high-resolution melting (MSHRM) in a total of 78 hypertensive and 49 control subjects. In this study, we could not identify a significant association between KLOTHO and ARNTL methylation and the hypertensive phenotype. Moreover, we could not find a direct association between KLOTHO and ARNTL methylation and the fasting blood sugar, triglycerides, total cholesterol, LDL-cholesterol, HDL-cholesterol, sodium (Na), creatinine (Cr), potassium (K), and urea levels in hypertensive patients. However, we found a significant difference between the methylated KLOTHO hypertensive patients and the unmethylated KLOTHO control subjects for potassium (K).

Background: Treacher Collins syndrome (TCS) is a rare congenital disorder of craniofacial development characterized by numerous developmental anomalies that are restricted to the head and neck. Most TCS cases are inherited in an autosomal dominant manner. The diagnosis of TCS relies on clinical and radiographic findings. The four genes involved in TCS are TCOF1, POLR1D, POLR1C, and POLR1B.

Case presentation: In this report, we present the case of a 7-year-old Moroccan boy who exhibited distinctive dysmorphic features, including coloboma and zygomatic bone hypoplasia. Upon genetic analysis, a mutation in the TCOF1 gene was identified, conclusively confirming the presence of Treacher Collins Syndrome. It is worthy that the correct etiological diagnosis was significantly delayed due to the initial misperception that the observed malformation syndrome was a result of drug teratogenicity.

Conclusions: This case highlights the importance of seeking pharmacovigilance advice if any adverse event occurs following medication use. Furthermore, requesting a genetic consultation to establish a confirmed etiological diagnosis for any malformation syndrome can significantly reduce the protracted social and psychological suffering that patients and their families may endure.

Salih myopathy is autosomal recessive hereditary early-onset myopathy with fatal cardiomyopathy. It is a rare and heterogeneous form of congenital titinopathies (TTN). Affected children have delayed motor development, normal mental development, and in further course dilated cardiomyopathy. Motor functions have a tendency to improve, but death occurs most often before 20 years of age due to arrhythmias. Our patient is a 2-year-old girl, born in severe perinatal asphyxia, with global hypotonia and poor spontaneous movements. She required immediate endotracheal intubation and mechanical ventilation was initiated without the possibility of cessation. Improvement in her neurological status was not observed. Due to her clinical presentation, we performed genetic testing and a diagnosis of Salih myopathy caused by combination of two heterozygous TTN mutations was confirmed. This case illustrates that Salih myopathy may have severe presentation from birth, with continuous necessity for mechanical ventilation, without any motor improvement.