Citations

Abstract Context Mandibular hypoplasia, deafness, progeroid features, and lipodystrophy (MDPL) syndrome is a rare, autosomal dominant disorder due to pathogenic heterozygous variants in POLD1. Clinical features of MDPL vary between patients; however, there is no previously reported genotype-phenotype association. Objective This work reports 14 new patients with lipodystrophy due to POLD1 variants and compares phenotypic differences between those with p.Ser605del and missense variants. Methods Genetic sequencing was performed on DNA of 14 patients for POLD1 variants, including exome (n = 10), genome (n = 1), and candidate gene (n = 3) sequencing. Comparisons of demographic, clinical features, and metabolic complications between carriers of POLD1 p.Ser605del and missense variants in our cases and those reported in the literature were made using the Fisher exact test for categorical variables and the t test for continuous variables. Results A total of 9 different POLD1 variants were identified in our patients, including 3 novel variants: p.Asp25Glufs*16, p.Arg507His, and p.Trp781Cys. Compared to individuals with missense variants (n = 15), those with the p.Ser605del (n = 26) POLD1 variant had significantly increased prevalence of mandibular hypoplasia (57% vs 100%, respectively; P = .015), small mouth (36% vs 100%, respectively; P = .015), crowded teeth (44% vs 91%, respectively; P = .046), and hypogonadism in male patients (0% vs 92%, respectively; P = .046). There were no differences in the prevalence of metabolic complications, such as diabetes, hypertriglyceridemia, and hepatic steatosis, in the two groups. Conclusion Individuals with the heterozygous POLD1 p.Ser605del variant had typical MDPL with more severe phenotype compared to those with missense variants with atypical MDPL.

AbstractBackgroundDiabetes mellitus (DM) in children and adolescents is typically caused by type 1 DM, followed by type 2 DM and maturity‐onset diabetes of the young (MODY). We report an unusual Asian Indian family in which three members presented with DM at ages 15, 20, and 30, but not fitting the typical clinical picture of type 1 DM, type 2 DM, or MODY. The primary objective was to elucidate the molecular genetic basis of DM in this family.MethodsThe proband, a 22‐year‐old man, had short stature, gray hair, osteoporosis, and markedly reduced subcutaneous fat on the body, especially on the extremities along with acanthosis nigricans, and developed myxoid malignant peripheral nerve sheath tumor. Detailed family history revealed multiple loops of consanguinity. The proband underwent whole‐genome sequencing, and seven relatives underwent whole‐exome sequencing.ResultsThe proband and three additional family members were found to have the homozygous c.561A>G nucleotide variant of WRN RecQ‐like helicase (WRN) gene consistent with the diagnosis of Werner's syndrome. The c.561A>G variant induces a new splicing site on exon 6 resulting in a truncated WRN protein, p.Lys187Trpfs*13.ConclusionOur report brings to attention the onset of DM during childhood or early adulthood in patients with Werner's syndrome who typically develop type 2 DM around the age of 30–40 years. Presence of consanguinity among parents, dysmorphic features, and malignancy should prompt consideration of diagnosis of Werner's syndrome.

Background: Mechanical injury in the conduction system requiring permanent pacemaker (PPM) associated with transcatheter aortic valve replacement (TAVR) procedure is a common complication. The objective of this study was to use ambulatory monitor BodyGuardian to assess late occurrence of atrioventricular block (AVB) after TAVR. Methods: This prospective study evaluated 365 patients who underwent TAVR at Mayo Clinic, Rochester, Minnesota between June 2016 and August 2017. Patients who received PPM for bradycardia after TAVR before discharge were considered as the PPM group. Those not requiring PPM received a BodyGuardian system (BodyGuardian group) for 30 days of continuous monitoring. Primary end point was Mobitz II or third-degree atrioventricular block (II/III AVB) at 30-day follow-up. Results: Of 365 patients, 74 who had a PPM or an implantable cardioverter-defibrillator before TAVR and 94 who were enrolled in other studies were excluded. Of 197 patients enrolled in the study, 70 (35.5%) received PPM and 127 had BodyGuardian before the hospital dismissal. Eleven of 127 (8.6%) BodyGuardian group required PPM within 30 days after TAVR for late occurrence of symptomatic bradycardia. In total, 33 of 197 (16.7%) patients developed II/III AVB (24 before and 9 after discharge). Thirty-four patients had preexisting right bundle branch block. Of them, 16 (47%) developed II/III AVB. Of 53 patients who developed new left bundle branch block after TAVR, 14% progressed to II/III AVB within 30 days. Conclusions: In patients without a standard post-TAVR pacing indication, yet a potential risk to develop AVB, a strategy of 30-day monitoring identifies additional patients who require permanent pacing.

Background: Percutaneous stellate ganglion blockade (SGB) has been used for drug-refractory electrical storm due to ventricular arrhythmia (VA); however, the effects and long-term outcomes have not been well studied. Methods: This study included 30 consecutive patients who had drug-refractory electrical storm and underwent percutaneous SGB between October 1, 2013, and March 31, 2018. Bupivacaine, alone or combined with lidocaine, was injected into the neck with good local anesthetic spread in the vicinity of the left stellate ganglion (n=15) or both stellate ganglia (n=15). Data were collected for patient clinical characteristics, immediate and long-term outcomes, and procedure-related complications. Results: Clinical characteristics included age, 58±14 years; men, 73.3%; and left ventricular ejection fraction, 34±16%. At 24 hours, 60% of patients were free of VA. Patients whose VA was controlled had a lower hospital mortality rate than patients whose VA continued (5.6% versus 50.0%; P =0.009). Implantable cardioverter-defibrillator interrogation showed a significant 92% reduction in VA episodes from 26±41 to 2±4 in the 72 hours after SGB ( P <0.001). Patients who died during the same hospitalization (n=7) were more likely to have ischemic cardiomyopathy (100% versus 43.5%; P =0.03) and recurrent VA within 24 hours (85.7% versus 26.1%; P =0.009). There were no procedure-related major complications. Conclusions: SGB effectively attenuated electrical storm in more than half of patients without procedure-related complications. Percutaneous SGB may be considered for stabilizing ventricular rhythm in patients for whom other therapies have failed.

Autosomal dominant polycystic kidney disease (ADPKD), one of the most common monogenetic disorders, is characterized by kidney failure caused by bilateral renal cyst growth. MicroRNAs (miRs) have been implicated in numerous diseases, but the role of these noncoding RNAs in ADPKD pathogenesis is still poorly defined. Here, we investigated the role of miR-21, an oncogenic miR, in kidney cyst growth. We found that transcriptional activation of miR-21 is a common feature of murine PKD. Furthermore, compared with renal tubules from kidney samples of normal controls, cysts in kidney samples from patients with ADPKD had increased levels of miR-21. cAMP signaling, a key pathogenic pathway in PKD, transactivated miR-21 promoter in kidney cells and promoted miR-21 expression in cystic kidneys of mice. Genetic deletion of miR-21 attenuated cyst burden, reduced kidney injury, and improved survival of an orthologous model of ADPKD. RNA sequencing analysis and additional in vivo assays showed that miR-21 inhibits apoptosis of cyst epithelial cells, likely through direct repression of its target gene programmed cell death 4 . Thus, miR-21 functions downstream of the cAMP pathway and promotes disease progression in experimental PKD. Our results suggest that inhibiting miR-21 is a potential new therapeutic approach to slow cyst growth in PKD.