Application of Clinical Genetics最新文献

Introduction: Sudden cardiac death (SCD) is a serious threat. In individuals under the age of 35 years sudden arrhythmic death is the most frequent cause. In younger persons, genetically determined cardiac diseases (eg, cardiomyopathies and ion-channel diseases) account for an important proportion of these cases.

Methods: We investigated the case of a 23-year-old male with SCD, specific ECG changes and left ventricular hypertrophy. Family history was significant for SCD in the paternal line. A precise analysis was performed by an international multidisciplinary expert panel including autopsy of the index patient's heart, molecular autopsy, whole-exome sequencing, analysis of the pedigree and examination of available family members.

Results: Three cases of SCD were reported in paternal relatives. The index patient exhibited specific ECG changes (ST-depression), which were also found in five paternal relatives and the brother of the index patient. Post-mortem analysis of the heart yielded mild idiopathic concentric hypertrophy without myocardial disarray. The genetic analysis of the index patient showed two nucleotide variations in two different genes (ANK2: c.11791G>A, MYO18B: c.3761G>A), which were also expressed in five relatives. Two family members had showed all indicators of the inherited syndrome including distinct ECG changes and genetic changes.

Conclusion: We describe a distinct inheritable syndrome causing SCD, characterized by specific ECG changes and mutations of ANK2 and MYO18. As far as we know this is the first description of this syndrome.

Introduction: Vitiligo is an acquired depigmenting skin disorder due to the loss of melanocyte function in the epidermis and hair follicles. The pathogenesis of vitiligo is multifactorial, with genetics being a predisposing factor. Previous studies had varying results regarding whether or not polymorphisms of vitamin D receptor (VDR) gene are associated with the risk of vitiligo in specific populations. This study investigated the association between three frequently analyzed VDR gene polymorphisms (ApaI, BsmI, TaqI) and susceptibility to vitiligo in Indonesian population.

Methods: Thirty-four vitiligo patients and 34 age- and sex-matched healthy subjects aged ≥18 years old were recruited in the Dermatology and Venereology Outpatient Clinic of Dr. Hasan Sadikin General Hospital, Bandung, Indonesia. Genomic deoxyribonucleic acid (DNA) was extracted from the peripheral blood using a DNA isolation kit. VDR gene polymorphisms (ApaI, BsmI, and TaqI) were investigated using the polymerase chain reaction-restriction-fragment length polymorphism method. The differences of genotype distributions and allele frequencies were statistically compared between case and control groups using Chi-square test.

Results: VDR gene polymorphisms were identified in 68 participants, consisting of Aa (n = 14), aa (n = 20), Bb (n = 15), bb (n = 19), and TT (n = 34) genotypes in the case group. In the control group, Aa (n = 6), aa (n = 28), Bb (n = 17), bb (n = 17), and TT (n = 34) genotypes were identified. However, only subjects with ApaI Aa genotype polymorphism had a 3.267-fold increased risk of developing vitiligo.

Conclusion: This study showed that ApaI Aa genotype polymorphism of the VDR gene increases the risk of vitiligo in Indonesian population.

Background: Hemophilia cannot be diagnosed in most laboratories of economically less-developed countries leading to high mortality and morbidity rates.

Aim: A diagnostic tool was established ranging from bleeding assessment and a simple bedside test of mixing venous clotting time (VCT) to comprehensive DNA analysis for patients with hemophilia.

Methods: Patients with known (n=80) and suspected hemophilia (n=14) were included. Their bleeding symptoms were initially evaluated using verified translated-Thai ISTH bleeding assessment tool. Then, blood samples were drawn using a two-syringe technique, 2 mL each was placed in three tubes, for the mixing VCT and citrate blood was kept for coagulogram and coagulation factor assay. Finally, DNA analysis was determined.

Results: A total of 94 patients with hemophilia (A68, B26) defined as severe (A 57, B 17), moderate (A 7, B 5), and mild degrees (A 4, B 4) with the mean (SD) age of 14.0 (11.7) years and 24 normal controls aged 25.5 (4.5), were enrolled in the study. The mean (SD) bleeding score of patients with hemophilia was 13.5 (5.5), which did not significantly differ between patients with hemophilia A and B. The mixing venous clotting time offered the presumptive diagnosis of hemophilia A and B, which were subsequently confirmed by the prolonged APTT, low FVIII:C and FIX:C and mutations on the factor VIII and IX genes.

Conclusion: A diagnostic tool for bleeding assessment, mixing venous clotting time, coagulogram, coagulation factor assay, and DNA analysis for patients with hemophilia has been established in the existing health-care system.

Introduction: Oncogenetic counseling has been provided at the University Hospital of Bern since 2004. Since the public announcement by Ms. Angelina Jolie in 2013 that she had undergone bilateral prophylactic mastectomy, other oncogenetic centers have reported an increase in consultations. We conducted a retrospective review of the oncogenetic consultations at our center to evaluate the presence and the consequences of a potential "Angelina Jolie effect" and to characterize this patient population over a decade.

Methods: All initial oncogenetic consultations between 2005 and 2015 were collected, using electronic records. Demographics, cancer type, testing, and mutation results, as well as consultation rates, were recorded. The yearly trends were analyzed using Joinpoint regression analysis (JPA).

Results: In total, 823 patient cases were included, mostly women (84%), half of them with a positive personal cancer history. A hereditary breast and ovarian cancer (HBOC) risk was the main reason for consultation (72%). Moreover, 22% of patients had a previously detected familial mutation. Two-thirds underwent testing, which yielded a positive test result in 31% of the cases. According to JPA, the consultation rate increased throughout the decade, with a significant upward trend from 2013. Rates of testing and positive results remained stable over time. Most patients (86%) fulfilled the referral criteria of published guidelines.

Discussion: At our center, we found retrospectively a disproportionate growth in the referral rate for HBOC cases compared to other oncological cases after the year 2013, but overall, no change in testing rates was detected.

Arrhythmogenic cardiomyopathy (AC) is a disease that involves electromechanical uncoupling of cardiomyocytes. This leads to characteristic histologic changes that ultimately lead to the arrhythmogenic clinical features of the disease. Initially thought to affect the right ventricle predominantly, more recent data show that it can affect both the ventricles or the left ventricle alone. Throughout the recent era, diagnostic modalities and criteria for AC have continued to evolve and our understanding of its clinical features in different age groups as well as the genotype to the phenotype correlations have improved. In this review, we set out to detail the epidemiology, etiologies, presentations, evaluation, and management of AC across the age continuum.

Objective: To investigate the relationship between unexplained recurrent pregnancy loss (URPL) and polymorphisms of homocysteine metabolism-related genes in women.

Materials and methods: A case-control study included 90 women with two or more consecutive unexplained pregnancy losses and 92 controlled women without miscarriage history; the female participants were in the age category of 18-35 years. The high-resolution melting technique was used to detect the single-nucleotide variants related to homocysteine metabolism disorder, namely MTHFR C677T, MTHFR A1298C, MTR A2756G, and MTRR A66G polymorphism.

Results: The MTHFR C677T polymorphism had significantly correlation with URPL. Indeed, the frequency of the677T allele and genotypes (677CT, 677TT) in the URPL group was significantly higher than that in the control group (p < 0.05). However, the allele, as well as genotype distribution of MTHFR A1298C, MTR A2756G, and MTRR A66G polymorphisms showed no significant difference (p > 0.05). MTHFR 677CT-1298AC genotype combination led to a 9.0-fold increased risk of URPL (OR 9.0; 95% CI, 2.25-35.99; p = 0.001), while the risk increased 10.0-fold (OR 10.0; 95% CI, 1.8-55.53; p = 0.008) when participants had more than the 3 variant loci.

Conclusion: The MTHFR C677T polymorphism was a risk factor for URPL, and determining the MTHFR C677T polymorphism had a potential prediction of URPL risk. Moreover, the MTHFR C677T and MTHFR A1298C joint mutants might have a synergistic effect on URPL. Conversely, there is a lack of evidence suggesting the URPL risk of MTHFR A1298C, MTR A2756G, and MTRR A66G polymorphisms.