Applying a genetic risk score model to enhance prediction of future multiple sclerosis diagnosis at first presentation with optic neuritis

Optic neuritis (ON) is associated with numerous immune-mediated inflammatory diseases, but 50% patients are ultimately diagnosed with multiple sclerosis (MS). Differentiating MS-ON from non-MS-ON acutely is challenging but important; non-MS ON often requires urgent immunosuppression to preserve vision. Using data from the United Kingdom Biobank we showed that combining an MS-genetic risk score (GRS) with demographic risk factors (age, sex) significantly improved MS prediction in undifferentiated ON; one standard deviation of MS-GRS increased the Hazard of MS 1.3-fold (95% confidence interval 1.07-1.55, P < 0.01). Participants stratified into quartiles of predicted risk developed incident MS at rates varying from 4% (95%CI 0.5-7%, lowest risk quartile) to 41% (95%CI 33-49%, highest risk quartile). The model replicated across two cohorts (Geisinger, USA, and FinnGen, Finland). This study indicates that a combined model might enhance individual MS risk stratification, paving the way for precision-based ON treatment and earlier MS disease-modifying therapy.

Development of a Polygenic Risk Score to Predict Diverticulitis

BACKGROUND

Despite its prevalence and associated morbidity, we remain limited in our ability to predict the course of a patient with diverticular disease. Although several clinical and genetic risk factors have been identified, we do not know how these factors relate to one another.

OBJECTIVE

Our aim was to determine whether a polygenic risk score could improve risk prediction for diverticulitis and recurrent diverticulitis compared with a model using only clinical factors.

DESIGN

This is an observational study.

SETTING

The study examines the predictive ability of a polygenic risk score for diverticulitis developed using prior genome-wide association studies and validated using the MyCode biobank.

PATIENTS

This study included patients of European ancestry in the Geisinger Health System who were enrolled in the MyCode Community Health biobanking program.

MAIN OUTCOME MEASURES

The ability of a polygenic risk score to predict diverticulosis, diverticulitis, and recurrent diverticulitis was the main outcome measure of this study.

RESULTS

A total of 60,861 patients were included, of whom 9912 (16.3%) had diverticulosis or diverticulitis (5015 with diverticulosis and 4897 with diverticulitis). When divided into deciles, our polygenic risk score stratified patients by risk of both diverticulosis and diverticulitis with a 2-fold difference in disease risk between the highest and lowest deciles for diverticulitis and a 4.8-fold difference for recurrent complicated diverticulitis. When compared with clinical factors alone, our polygenic risk score was able to improve risk prediction of recurrent diverticulitis.

LIMITATIONS

Our population is largely located in a single geographic region and were classified by disease status, using international classification of diseases codes.

CONCLUSIONS

This predictive model stratifies patients based on genetic risk for diverticular disease. The increased frequency of recurrent disease in our high-risk patients suggests that a polygenic risk score, in addition to other factors, may help guide the discussion regarding surgical intervention. See Video Abstract .

DESARROLLO DE UNA PUNTUACIN DE RIESGO POLIGNICO PARA PREDECIR LA DIVERTICULITIS

ANTECEDENTES:A pesar de su prevalencia y morbilidad asociada, nuestra capacidad para predecir el curso en un paciente con enfermedad diverticular sigue siendo limitada. Si bien se han identificado varios factores de riesgo clínicos y genéticos, no sabemos cómo se relacionan estos factores entre sí.OBJETIVO:Determinar si una puntuación de riesgo poligénico podría mejorar la predicción del riesgo de diverticulitis y diverticulitis recurrente en comparación con un modelo que utiliza solo factores clínicos.DISEÑO:Un estudio observacional que examina la capacidad predictiva de una puntuación de riesgo poligénico para la diverticulitis desarrollada usando estudios previos de asociación amplia del genoma y validada usando el biobanco MyCode.ÁMBITOS Y PACIENTES:Pacientes de ascendencia europea en el Sistema de Salud Geisinger que estaban inscritos en el programa de biobancos MyCode Community Health.PRINCIPALES MEDIDAS DE VALORACIÓN:La capacidad de una puntuación de riesgo poligénico para predecir diverticulosis, diverticulitis y diverticulitis recurrente.RESULTADOS:Se incluyeron un total de 60.861 pacientes, de los cuales 9.912 (16,3%) presentaban diverticulosis o diverticulitis (5.015 con diverticulosis y 4.897 con diverticulitis). Cuando se dividió en deciles, nuestra puntuación de riesgo poligénico estratificó a los pacientes según el riesgo de diverticulosis y diverticulitis con una diferencia de 2 veces en el riesgo de enfermedad entre los deciles más alto y más bajo para diverticulitis y una diferencia de 4,8 veces para diverticulitis complicada recurrente. En comparación con los factores clínicos solos, nuestra puntuación de riesgo poligénico pudo mejorar la predicción del riesgo de diverticulitis recurrente.LIMITACIONES:Nuestra población se encuentra en gran parte en una sola región geográfica y se clasificó por estado de enfermedad utilizando códigos de clasificación internacional de enfermedades.CONCLUSIONES:Este modelo predictivo estratifica a los pacientes en función del riesgo genético de enfermedad diverticular. La mayor frecuencia de enfermedad recurrente en nuestros pacientes de alto riesgo sugiere que un puntaje de riesgo poligénico, además de otros factores, puede ayudar a guiar la discusión sobre la intervención quirúrgica. (Traducción- Dr. Ingrid Melo ).

0901 Role of Nasopharynx Radiography in Diagnosis of Sleep Disordered Breathing in Children

Introduction

Sleep disordered breathing (SDB) in children comprises a wide spectrum of presentation ranging from primary snoring (prevalence 6-12%) to obstructive sleep apnea (OSA; prevalence 1-3%). In younger children, SDB is often secondary to adenotonsillar hypertrophy. Polysomnography is the gold standard test for evaluation of sleep disordered breathing. Yet, many providers order ancillary tests such as Radiography of Nasopharynx (NPX-ray) to assess for adenoidal hypertrophy. Previous studies evaluating efficacy of NPX-rays to diagnose airway obstruction have shown mixed results.

Methods

Retrospective chart review of 65 consecutive normally developed children who have had diagnostic polysomnography and NPX-rays over the past 3 years was performed. Data on age, sex, Obstructive Apnea Hypopnea Index (OAHI) and NPX-ray findings were collected. Our cohort mostly had the following diagnosis such as GERD, Asthma, Allergic rhinitis, ADHD and Obesity. Our cohort did not have neurological disorders or medications that could affect tone of upper airway. Standard pediatric AHI criteria was applied to categorize mild, moderate and severe OSA.

Results

Our cohort’s age ranged from 3-18 years (median age 10 years); 43 were males. Of the 24 children with normal sized adenoids with no obstruction; 6 had severe OSA and 4 had moderate OSA. 3 had hypertrophied adenoids on X-ray with occlusion of nasopharynx but only had mild OSA. Of the 15 children with prominent adenoids with some narrowing but no occlusion; 9 had severe OSA. Of the 9 children that had hypertrophied adenoids with no occlusion; 3 had moderate OSA and 3 had severe OSA. Of the 12 with mild enlargement, 4 had severe OSA. None of the 19 children with severe OSA showed airway occlusion by adenoids.

Conclusion

In our study, the size of the adenoids on X-ray of the Nasopharynx did not correlate with severity of SDB in children. Airway obstruction in OSA is dynamic and can occur at multiple sites affected by anatomical factors and upper airway collapsibility. As use of Nasopharyngeal radiography involves exposure to radiation, it should be used judiciously in diagnosis of SDB in children. Polysomnography is the gold standard test for evaluation of SBD in children.

Support

None.

0912 Central Sleep Apnea Patterns On Pediatric Polysomnograms

Introduction

Central sleep apneas (CA) are frequently seen on pediatric polysomnograms (PPSG) independently or in conjunction with obstructive sleep apnea (OSA). In the pediatric population, the AASM defines CA as the absence of chest and/or abdominal movement associated with a cessation of airflow of more than 20s or longer than 2 baseline respiratory cycles if associated with an arousal, an awakening or oxygen desaturation ≥ 3%. Scoring CAs on PPSG based on AASM definition can cause confusion among providers as CAs are generally associated with central nervous disorders causing reduced or absent respiratory drive.

Methods

Retrospective review of 71 consecutive diagnostic PPSGs to analyze patterns of CAs scored per AASM definition was performed. None of the children had a disorder causing reduced respiratory drive. Data on age, obstructive AHI (Apnea Hypopnea Index), CO2, Oxygen saturation, Central AHI and diagnosis were collected.

Results

68 of 71 children had varying degree of OSA and CAs. Three main patterns of CAs were observed: occurring in NREM, following sigh breaths or arousals and CAs seen in REM sleep. CO2 and oxygen saturation were in the normal range.

Conclusion

In our study, CAs were more often seen in young children related to reduced functional residual capacity and immaturity of chest wall. CAs in REM sleep was seen more often in children with lung disorders and gastroesophageal reflux. CAs associated with arousals/awakenings were seen in conjunction with OSA or periodic limb movement disorder (PLMD). Though a finding of CAs &gt;5/hour is considered significant, the minimum number of events required to cause a specific disorder or syndrome remains elusive and may be different in different patient populations. As such, there is no threshold of the number of central apneas associated with disease. CAs associated with disorders causing reduced or absent respiratory drive are mostly seen in NREM sleep and associated with abnormal gas exchange. The context in which the CAs are seen on PPSGs should be clearly described to avoid confusion among ordering providers. In CAs associated with arousals/awakenings, it is important to target the cause of arousals such as OSA or PLMD.

Support

None

Genomic profiling of human vascular cells identifies TWIST1 as a causal gene for common vascular diseases

Genome-wide association studies have identified multiple novel genomic loci associated with vascular diseases. Many of these loci are common non-coding variants that affect the expression of disease-relevant genes within coronary vascular cells. To identify such genes on a genome-wide level, we performed deep transcriptomic analysis of genotyped primary human coronary artery smooth muscle cells (HCASMCs) and coronary endothelial cells (HCAECs) from the same subjects, including splicing Quantitative Trait Loci (sQTL), allele-specific expression (ASE), and colocalization analyses. We identified sQTLs for TARS2, YAP1, CFDP1, and STAT6 in HCASMCs and HCAECs, and 233 ASE genes, a subset of which are also GTEx eGenes in arterial tissues. Colocalization of GWAS association signals for coronary artery disease (CAD), migraine, stroke and abdominal aortic aneurysm with GTEx eGenes in aorta, coronary artery and tibial artery discovered novel candidate risk genes for these diseases. At the CAD and stroke locus tagged by rs2107595 we demonstrate colocalization with expression of the proximal gene TWIST1. We show that disrupting the rs2107595 locus alters TWIST1 expression and that the risk allele has increased binding of the NOTCH signaling protein RBPJ. Finally, we provide data that TWIST1 expression influences vascular SMC phenotypes, including proliferation and calcification, as a potential mechanism supporting a role for TWIST1 in CAD.

Genetic and Epigenetic Fine Mapping of Complex Trait Associated Loci in the Human Liver

Deciphering the impact of genetic variation on gene regulation is fundamental to understanding common, complex human diseases. Although histone modifications are important markers of gene regulatory elements of the genome, any specific histone modification has not been assayed in more than a few individuals in the human liver. As a result, the effects of genetic variation on histone modification states in the liver are poorly understood. Here, we generate the most comprehensive genome-wide dataset of two epigenetic marks, H3K4me3 and H3K27ac, and annotate thousands of putative regulatory elements in the human liver. We integrate these findings with genome-wide gene expression data collected from the same human liver tissues and high-resolution promoter-focused chromatin interaction maps collected from human liver-derived HepG2 cells. We demonstrate widespread functional consequences of natural genetic variation on putative regulatory element activity and gene expression levels. Leveraging these extensive datasets, we fine-map a total of 74 GWAS loci that have been associated with at least one complex phenotype. Our results reveal a repertoire of genes and regulatory mechanisms governing complex disease development and further the basic understanding of genetic and epigenetic regulation of gene expression in the human liver tissue.

Cell-specific post-transcriptional regulation of γ-synuclein gene by micro-RNAs

γ-Synuclein is a member of the synucleins family of small proteins, which consists of three members:α, β- and γ-synuclein. γ-Synuclein is abnormally expressed in a high percentage of advanced and metastatic tumors, but not in normal or benign tissues. Furthermore, γ-synuclein expression is strongly correlated with disease progression, and can stimulate proliferation, induce invasion and metastasis of cancer cells. γ-Synuclein transcription is regulated basically through the binding of AP-1 to specific sequences in intron 1. Here we show that γ-synuclein expression may be also regulated by micro RNAs (miRs) on post-transcriptional level. According to prediction by several methods, the 3′-untranslated region (UTR) of γ-synuclein gene contains targets for miRs. Insertion of γ-synuclein 3′-UTR downstream of the reporter luciferase (LUC) gene causes a 51% reduction of LUC activity after transfection into SKBR3 and Y79 cells, confirming the presence of efficient targets for miRs in this fragment. Expression of miR-4437 and miR-4674 for which putative targets in 3′-UTR were predicted caused a 61.2% and 60.1% reduction of endogenous γ-synuclein expression confirming their role in gene expression regulation. On the other hand, in cells overexpressing γ-synuclein no significant effect of miRs on γ-synuclein expression was found suggesting that miRs exert their regulatory effect only at low or moderate, but not at high level of γ-synuclein expression. Elevated level of γ-synuclein differentially changes the level of several miRs expression, upregulating the level of some miRs and downregulating the level of others. Three miRs upregulated as a result of γ-synuclein overexpression, i.e., miR-885-3p, miR-138 and miR-497 have putative targets in 3′-UTR of the γ-synuclein gene. Some of miRs differentially regulated by γ-synuclein may modulate signaling pathways and cancer related gene expression. This study demonstrates that miRs might provide cell-specific regulation of γ-synuclein expression and set the stage to further evaluate their role in pathophysiological processes.

Mapping QTLs for popping ability in a popcorn x flint corn cross

Popping expansion volume (PEV) in popcorn (Zea mays L.) is a distinct heritable character and defined as the ratio of the volume after popping to the volume before popping. PEV is quantitatively inherited and 3-4 genes/quantitative trait loci (QTLs) have been implicated. In the present study, we have dissected the quantitative PEV into two component traits, viz., flake volume (FV) and percent unpopped kernels (UPK), and mapped QTLs using SSR markers for all three traits with 194 F3 families derived from a popcorn (A-1-6) x flint corn (V273) cross. Heritability (broad sense) estimates for PEV, FV and UPK based on F3 mean bases were 0.72, 0.54 and 0.68, respectively. The QTL analyses for the three traits based on combined environment data were performed by composite interval mapping using QTL cartographer. Four QTLs were identified for PEV on chromosomes 1, 3, 8 and 10, which together explained 62% of the phenotypic variance (sigma2p). Four QTLs were found on chromosomes 1, 5, 9 and 10 for FV (explaining 44% of sigma2p) and five QTLs for UPK on chromosomes 1, 3, 4, 5 and 9 (explaining 57% of sigma2p). The relative efficiency estimates of marker-based selection in comparison to phenotypic selection for PEV (1.10), FV (1.22) and UPK (1.11) indicated that marker-based selection could be relatively more efficient. The QTL on chromosome 1S for PEV was found to be most significant, where QTLs for hard endosperm starch concentration had been detected earlier.

Dorsal placement of the pedicled preputial/penile onlay flap for anterior urethral stricture: is it more logical?

OBJECTIVES

We present our preliminary experience in the management of inflammatory anterior urethral strictures with a dorsally/dorsolaterally placed penile/preputial vascularized flap and discuss the distinct advantages of this procedure over a traditional ventrally placed flap.

METHODS

Twelve patients (age, 20-66 years; mean age, 40.5 years) with recurrent inflammatory strictures of the penile and/or bulbar urethra (penile, 2; bulbar, 5 and bulbopenile, 5) were treated with dorsally/dorsolaterally placed penile/preputial (penile skin, 5; prepuce, 7) vascularized flap substitution urethroplasty. Prior to surgery, 7 patients had suprapubic cystostomy for acute urinary retention and 5 had a mean peak flow rate of 6.2 ml/sec. Inferior pubectomy was performed as an adjunct in two patients to facilitate proximal placement of the flap. Follow-up (5 to 24 months; mean, 15.5) included uroflowmetry and retrograde urethrograms at 6, 12 and 18 months, and thereafter as required.

RESULTS

The mean stricture length was 5.8 cm (range, 3 to 12 cm) and all strictures were associated with dense spongifibrosis. Temporary urethral fistulae, which healed spontaneously, occurred in 4 patients. The clinical and radiological outcome during the mean follow up of 15.5 months was gratifying. The mean peak flow rate improved to 24.2 ml/sec. No stricture recurrence has been noted to date. Sacculation of the flap, diverticulum formation and post-void dribble have not been encountered. None of the patients developed chordee or erectile dysfunction.

CONCLUSIONS

Dorsal onlay preputial/penile flap urethroplasty is a versatile procedure in the treatment of inflammatory anterior urethral strictures. The dorsal pedicle flap may be anatomically and functionally more logical as compared to the traditional ventrally placed flap.

Laparoscopic surgeries for the bladder

Various reparative, reconstructive, extirpative, and miscellaneous surgeries of the bladder with laparoscopic techniques are in the process of evolution. Our increasing expertise enhanced by improved instrumentation make these procedures feasible and encourage us to venture into this relatively less explored arena of laparoscopic urology.

Ureteroscopic lithotripsy using mini-endoscope and Swiss lithoclast: experience in 147 cases

To evaluate the efficacy of a semirigid mini-endoscope and the Swiss Lithoclast compared with a conventional rigid endoscope and ultrasound, the results of transurethral ureteroscopic lithotripsy in 147 patients over a period of 30 months were analyzed according to the type of ureteroscope (rigid v semirigid) and energy (ultrasound v Lithoclast) used. In the initial 25 cases (Group I), a conventional rigid ureteroscope and ultrasound were used. The latter 122 patients (Group II) were subjected to ureteroscopic lithotripsy using a miniscope and the Lithoclast. The results were superior in Group II with respect to the overall success rate (p = 1.6 x 10[-2]), first-attempt success rate (p = 2.9 x 10[-4]), and the need for ureteral dilation (P = 1.0 x 10[-6]) compared with Group I. There were no major complications. Overall, minor complications (hematuria and urinary tract infection) were observed in 25% of the cases. Further, the results of ureteroscopic lithotripsy in Group II were comparable to those of SWL in situ for upper ureteral calculi and better than for those located in the iliac and lower ureter as reported previously. Our results demonstrate that the Swiss Lithoclast provides effective fragmentation of even hard and smooth stones without increasing the complication rate. This lithotripter is reliable, safe, and simple to operate. In addition, the cost of maintenance is almost nil.

In vitro anthelmintic activity of root-tuber extract of Flemingia vestita, an indigenous plant in Shillong, India

The in vitro activity of root-tuber-peel extract of Flemingia vestita, an indigenous plant consumed by the natives in Northeast India, was tested against helminth parasites. Live parasites (nematode: Ascaris suum from pigs, A. lumbricoides from humans, Ascaridia galli and Heterakis gallinarum from domestic fowl; cestode: Raillietina echinobothrida from domestic fowl; trematode: Paramphistomum sp. from cattle) were collected in 0.9 % physiological buffered saline (PBS) and maintained at 37 +/- 1 degrees C. In vitro treatment of the parasites with the crude extract (50 mg/ml) in PBS revealed complete immobilization of the trematode and cestode in about 43 and 20 min, respectively. However, the cuticle-covered nematodes did not show any change in physical activity and remained viable even after a long period of exposure to the extract. Exposure of R. echinobothrida to genistein (0.5 mg/ml), an active principle isolated from the root-tuber peel, caused spontaneous loss of movement (paralysis) in 4.5 h, which was slower than the time required for praziquantel, the reference flukicide and cestodicide. The treated parasites showed structural alteration in their tegumental architecture. This study suggests the vermifugal activity of this plant extract against trematodes and cestodes.