Phenotypic Variability of a Pathogenic PKP2 Mutation in an Italian Family Affected by Arrhythmogenic Cardiomyopathy and Juvenile Sudden Death: Considerations From Molecular Autopsy to Sport Restriction.

Background: Arrhythmogenic cardiomyopathy (ACM) is a genetic disorder with an estimated prevalence between 1:2,000 and 1:5,000 and is characterized by the fibrofatty replacement of cardiomyocytes that predisposes to malignant arrhythmias, heart failure, and sudden cardiac death. The diagnosis is based on the 2010 Task Force Criteria including family history, electrocardiographic traits and arrhythmogenic pattern, specific gene mutations, and structural and/or histological abnormalities. Most ACMs display an autosomal dominant mode of inheritance often with incomplete penetrance and variable expressivity. Genetic screening of patients with ACM identifies pathogenic or likely pathogenic variants, prevalently in genes encoding the cardiac desmosome (PKP2, DSP, DSC2, DSG2, and JUP) or less frequently in non-desmosomal genes (CTNNA3, PLN, TMEM43, RYR2, SCN5A, CDH2, and DES). Methods: In the present study, we performed molecular autopsy in a boy who died suddenly during physical exertion. In addition to post-mortem examination, a DNA sample was analyzed with next-generation sequencing (NGS). Results: The genetic analysis revealed the presence of pathogenic heterozygous c.314del (p.Pro105Leufs*7) frameshift variant in the PKP2 gene. Cascade screening of family members allowed us to identify 12 mutation carriers and to intervene on subjects at risk, many of whom were athletes. Conclusions: Molecular autopsy can establish cardiogenetic diagnosis and allow appropriate preventative measures in high-risk relatives.

Role of Subclinical Iatrogenic Hyperthyroidism in the Setting of Heart Disease and Arrhythmic Burden.

BACKGROUND: Subclinical hyperthyroidism is defined by a subnormal serum thyroidstimulating hormone (TSH) level with normal free thyroxine (FT4) and free triiodothyronine (FT3) levels. Its prevalence varies from 0.6% to 16% in the elderly and can increase to 20% in patients receiving thyroid hormone replacement therapy. Thyroid disease and/or replacement therapy are frequently associated with cardiovascular involvement. CASES PRESENTATION: We report three clinical cases of patients with initial subclinical hyperthyroidism and cardiological manifestations, including supraventricular and ventricular extrasystoles, prolapse of the mitral valve with severe regurgitation, higher mean heart rate and deterioration of the arrhythmias on arrhythmogenic dysplasia substrate. CONCLUSION: We discuss the role of appropriate and early correction of thyroid dysfunction in improving cardiological manifestations.

Molecular diagnostic workflow, clinical interpretation of sequence variants, and data repository procedures in 140 individuals with familial cerebral cavernous malformations.

Familial cerebral cavernous malformation (FCCM) is an autosomal dominant vascular disorder caused by heterozygous deleterious variants in KRIT1, CCM2 or PDCD10. In a previous study, we presented the clinical and molecular findings in 140 FCCM individuals. In the present work, we report supporting information on (a) applied diagnostic workflow; (b) clinical significance of molecular findings according to the American College of Medical Genetics and Genomics/Association for Molecular Pathology recommendations; (c) standardization of molecular and clinical data according to the Human Phenotype Ontology; (d) preliminary genotype-phenotype correlations on a subgroup of patients by considering sex, age at diagnosis, neurological symptoms, and number and anatomical site(s) of vascular anomalies; (e) datasets submitted to the Leiden Open Variation Database. An overview of the changes of our diagnostic approach before and after the transition to next-generation sequencing is also reported. This work presents the full procedure that we apply for molecular testing, data interpretation and storing in public databases in FCCM.

Electrical Remodeling of Ventricular Repolarization Abnormality after Treatment in Pheochromocytoma: U Wave Finding in a Retrospective Analysis.

Background: Pheochromocytoma is a rare neuroendocrine tumor, clinically characterized by high blood pressure, palpitations, and headache. It is often associated with abnormalities of the ventricular repolarization phase; the dispersion of ventricular repolarization is the basis for ventricular arrhythmias (torsion de point, ventricular tachycardia or ventricular fibrillation). Objectives: Analysis of abnormal ventricular repolarization focused on the presence and amount of U wave in patients affected by pheochromocytoma and its modification after surgery. Materials and Methods: We reviewed pathology records of 722 patients admitted for adrenal nodule or suspected chromaffin-cell tumor and identified 39 patients affected by pheochromocytoma. Metanephrine, normetanephrine, and 3-methoxytyramine have been assessed by determining concentrations in 24-hour urine collection. Standard 12-lead electrocardiogram records have been reviewed with analysis of heart rate, P wave, PR interval, QRS duration, QTc, and U wave. Then we selected and compared 22 patients of 39 affected by pheochromocytoma, with both clinical and electrocardiographic data before and after surgery. Results: In our cohort of 39 patients affected by pheochromocytoma, we found U wave in ECG, before treatment, in 82.8 percent of patients, while only 37.0 percent after treatment (p<0.001) and we observed a statistically significant correlation between this wave and the urinary metanephrine. After surgery, in the selected 22 patients, we observed a clear significant reduction in systemic blood pressure, fasting glucose, metanephrine, normetanephrine, and 3-methoxytyramine. We found a significant reduction of U wave presence and leads involved in these patients after surgery (90.9% versus 9%). We observed a linear correlation between the amount of U waves in 12-lead electrocardiogram and metanephrine (r2=0.333, p=0.015), 3-methoxytyramine levels (r2=0.458, p=0.006), and tumor size (r2=0.429, p=0.003). Conclusions: In our retrospective analysis, patients affected by pheochromocytoma presented U wave in electrocardiogram. The presence and amount of U wave were associated with the metanephrine levels and the tumor size with significant reduction after surgical removal.

Serum uric acid as a prognostic marker in the setting of advanced vascular disease: a prospective study in the elderly.

BACKGROUND: Many epidemiological studies analyze the relationship between hyperuricemia and cardiovascular outcomes. This observational prospective study investigates the association of serum uric acid (SUA) levels with adverse cardiovascular events and deaths in an elderly population affected by advanced atherosclerosis. METHODS: Two hundred and seventy six elderly patients affected by advanced atherosclerosis (217 males and 59 females; aged 71.2 ± 7.8 years) were included. All patients were assessed for history of cardiovascular disease, cancer, obesity and traditional risk factors. Patients were followed for approximately 31 ± 11 months. Major events were recorded during follow-up, defined as myocardial infarction, cerebral ischemia, myocardial and/or peripheral revascularization and death. RESULTS: Mean SUA level was 5.47 ± 1.43 mg/dL; then we further divided the population in two groups, according to the median value (5.36 mg/dL). During a median follow up of 31 months (5 to 49 months), 66 cardiovascular events, 9 fatal cardiovascular events and 14 cancer-related deaths have occurred. The patients with increased SUA level presented a higher significant incidence of total cardiovascular events (HR: 1.867, P = 0.014, 95% CI: 1.134-3.074). The same patients showed a significant increased risk of cancer-related death (HR: 4.335, P = 0.025, 95% CI: 1.204-15.606). CONCLUSIONS: Increased SUA levels are independently and significantly associated with risk of cardiovascular events and cancer related death in a population of mainly elderly patients affected by peripheral vasculopathy.

Coexistence of multiple endocrine neoplasia type 1 and type 2 in a large Italian family.

To describe the coexistence of mutations of both the multiple endocrine neoplasia type 1 (MEN1) and type 2 (MEN2) genes in a large Italian family and evaluate if it could be associated with more aggressive clinical manifestations of the two syndromes. Blood samples were obtained for genetic and biochemical analyses. The RET gene exons (8, 10, 11, 13, 14, 15, 16, 18) and the MEN1 coding regions, including the exon-intron boundaries, were amplified by PCR and directly sequenced. We identified two germline mutations in the proband: the first one, K666M, located at the exon 11 of RET proto-oncogene and the second one, IVS4+1G>T, located in the MEN1 gene. The functional characterization of IVS4+1G>T variation, located in the splicing donor site of exon 4 of MEN1 gene, caused the in-frame junction of exon 3 to exon 5, thus obtaining a shorter protein. The same proband's germline mutations were found in 16 relatives out of 21 screened subjects: 8 carried IVS4+1G>T, 4 RET K666M, and 4 both the mutations. This is the second report in literature of coexistence in the same family of germline mutations of both RET proto-oncogene and MEN1 gene. The simultaneous presence of the two mutations was not apparently associated with more aggressive diseases, since at last follow-up all patients appeared to be disease-free or well compensated by medical therapy; finally, no one exhibited metastatic diseases.

ENPP1 Q121 variant, increased pulse pressure and reduced insulin signaling, and nitric oxide synthase activity in endothelial cells.

OBJECTIVE: Insulin resistance induces increased pulse pressure (PP), endothelial dysfunction (ED), and reduced bioavailability of endothelium-derived nitric oxide (NO). The genetic background of these 3 cardiovascular risk factors might be partly common. The ENPP1 K121Q polymorphism is associated with insulin resistance and cardiovascular risk. METHODS AND RESULTS: We investigated whether the K121Q polymorphism is associated with increased PP in white Caucasians and with ED in vitro. In 985 individuals, (390 unrelated and 595 from 248 families), the K121Q polymorphism was associated with PP (P=8.0 x 10(-4)). In the families, the Q121 variant accounted for 0.08 of PP heritability (P=9.4 x 10(-4)). This association was formally replicated in a second sample of 475 individuals (P=2.6 x 10(-2)) but not in 2 smaller samples of 289 and 236 individuals (P=0.49 and 0.21, respectively). In the individual patients' data meta-analysis, comprising 1985 individuals, PP was associated with the Q121 variant (P=1.2 x 10(-3)). Human endothelial cells carrying the KQ genotype showed, as compared to KK cells, reduced insulin-mediated insulin receptor autophosphorylation (P=0.03), Ser(473)-Akt phosphorylation (P=0.03), and NO synthase activity (P=0.003). CONCLUSIONS: Our data suggest that the ENPP1 Q121 variant is associated with increased PP in vivo and reduced insulin signaling and ED in vitro, thus indicating a possible pathogenic mechanism for the increased cardiovascular risk observed in ENPP1 Q121 carriers.

Increased urinary albumin excretion, insulin resistance, and related cardiovascular risk factors in patients with type 2 diabetes: evidence of a sex-specific association.

OBJECTIVE: While the relevant role of insulin resistance in the pathogenesis of increased urinary albumin excretion (UAE) is well established in type 1 diabetes, its contribution in type 2 diabetes is controversial. Our aim was to investigate whether insulin resistance was associated with increased UAE in a large cohort of patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: A total of 363 men and 349 women, aged 61 +/- 9 years, with a disease duration of 11 +/- 9 years and HbA(1c) levels of 8.6 +/- 2.0% were included. Insulin resistance was derived from the homeostasis model assessment of insulin resistance (HOMA(IR)), and UAE was derived from the albumin-to-creatinine ratio (ACR) defined as increased if the value was > or =2.5 mg/mmol in men and > or =3.5 mg/mmol in women. ACR was correlated with HOMA(IR) (r = 0.15, P = 0.0001), independently of age, disease duration, blood pressure, HbA(1c), triglycerides, waist circumference, and smoking. RESULTS: When the two sexes were investigated separately, a significant correlation between ACR and HOMA(IR) was reached in men (n = 363; r = 0.21, P = 0.0001) but not women (n = 349; r = 0.08, P = 0.14), suggesting that insulin resistance and sex may interact (P for interaction = 0.04) in determining UAE. When men were subgrouped into quartiles of HOMA(IR), those of the third and fourth quartile (i.e., the most insulin resistant) were at higher risk to have increased ACR than patients of the first quartile (third quartile: odds ratio 2.2 [95% CI 1.2-4.2], P = 0.01) (fourth quartile: 4.1 [2.2-7.9], P = 0.00002). Finally, ACR was significantly higher in men with two or more insulin resistance-related cardiovascular risk factors (i.e., abdominal obesity, dyslipidemia, and arterial hypertension) than in men with fewer than two insulin resistance-related cardiovascular risk factors (0.90 [0.2-115.1] vs. 1.56 [0.1-1367.6], respectively, P = 0.005). CONCLUSIONS: In type 2 diabetic patients, increased UAE is strongly associated with insulin resistance and related cardiovascular risk factors. This association seems to be stronger in men than in women.