Understanding the Genetics of Early-Onset Obesity in a Cohort of Children From Qatar.

CONTEXT: Monogenic obesity is a rare form of obesity due to pathogenic variants in genes implicated in the leptin-melanocortin signaling pathway and accounts for around 5% of severe early-onset obesity. Mutations in the genes encoding the MC4R, leptin, and leptin receptor are commonly reported in various populations to cause monogenic obesity. Determining the genetic cause has important clinical benefits as novel therapeutic interventions are now available for some forms of monogenic obesity. OBJECTIVE: To unravel the genetic causes of early-onset obesity in the population of Qatar. METHODS: In total, 243 patients with early-onset obesity (above the 95% percentile) and age of onset below 10 years were screened for monogenic obesity variants using a targeted gene panel, consisting of 52 obesity-related genes. RESULTS: Thirty rare variants potentially associated with obesity were identified in 36 of 243 (14.8%) probands in 15 candidate genes (LEP, LEPR, POMC, MC3R, MC4R, MRAP2, SH2B1, BDNF, NTRK2, DYRK1B, SIM1, GNAS, ADCY3, RAI1, and BBS2). Twenty-three of the variants identified were novel to this study and the rest, 7 variants, were previously reported in literature. Variants in MC4R were the most common cause of obesity in our cohort (19%) and the c.485C>T p.T162I variant was the most frequent MC4R variant seen in 5 patients. CONCLUSION: We identified likely pathogenic/pathogenic variants that seem to explain the phenotype of around 14.8% of our cases. Variants in the MC4R gene are the commonest cause of early-onset obesity in our population. Our study represents the largest monogenic obesity cohort in the Middle East and revealed novel obesity variants in this understudied population. Functional studies will be required to elucidate the molecular mechanism of their pathogenicity.

Investigation of Genetic Causes in Patients with Congenital Heart Disease in Qatar: Findings from the Sidra Cardiac Registry.

Congenital heart disease (CHD) is one of the most common forms of birth defects worldwide, with a prevalence of 1-2% in newborns. CHD is a multifactorial disease partially caused by genetic defects, including chromosomal abnormalities and single gene mutations. Here, we describe the Sidra Cardiac Registry, which includes 52 families and a total of 178 individuals, and investigate the genetic etiology of CHD in Qatar. We reviewed the results of genetic tests conducted in patients as part of their clinical evaluation, including chromosomal testing. We also performed whole exome sequencing (WES) to identify potential causative variants. Sixteen patients with CHD had chromosomal abnormalities that explained their complex CHD phenotype, including six patients with trisomy 21. Moreover, using exome analysis, we identified potential CHD variants in 24 patients, revealing 65 potential variants in 56 genes. Four variants were classified as pathogenic/likely pathogenic based on the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG/AMP) classification; these variants were detected in four patients. This study sheds light on several potential genetic variants contributing to the development of CHD. Additional functional studies are needed to better understand the role of the identified variants in the pathogenesis of CHD.

Landscape of childhood epilepsies - A multi-ethnic population-based study.

OBJECTIVE: To describe the clinical features of childhood epilepsy in Qatar. METHODS: A retrospective cross-sectional chart review analysis was conducted at the only tertiary pediatric hospital in Qatar in 1422 patients with epilepsy followed between November 2016 and October 2019. RESULTS: 55% (781) were males and 70% were non-Qatari. Age of epilepsy onset was in the neonatal period in 9% (114/1207 patients). In the non-neonatal cohort, mean age of onset was 4 yrs 9mos ( ± 1.4mos). Focal epilepsy was the predominant epilepsy type in 45% (594/1314 patients) versus generalized epilepsy in 37% and combined focal/generalized epilepsy in 12%. Etiology was unknown in most children (782/1363, 57%) whereas structural and genetic causes represented 23% and 11% of cases respectively. No differences in epilepsy type and etiology were found between different ethnic groups. Children with genetic or structural epilepsies had an earlier epilepsy onset compared to those with unknown etiologies. At the last follow up, only 36% of patients were seizure-free and 12% (170/1422) had a history of status epilepticus. Medically refractory epilepsy was found in 37% (527/1407) of patients, with the most common etiologies being unknown (36%) and structural (37%). Neurodevelopmental co-morbidities were present in most patients (62%), with global developmental delay (47%) and learning/school difficulties (22%) being the most prevalent. 94% of patients with somatic co-morbidities had concomitant neurodevelopmental co-morbidities. Risk factors associated with an increased risk of co-morbidities and intractable epilepsy included early age of epilepsy onset (< 2 years of age); etiology; antenatal risk factors; history of previous central nervous system infection; history of status epilepticus and a family history of consanguinity and epilepsy. SIGNIFICANCE: This large multi-ethnic population-based study confirms that the prevalence, incidence and clinical features of epilepsy in Qatar is in accordance with other epidemiologic studies and highlights risk factors for the development of co-morbidities and medically-intractable epilepsy.

Chest compression by two-thumb encircling method generates higher carotid artery blood flow in swine infant model of cardiac arrest.

OBJECTIVE: Two-Thumb(TT) technique provides superior quality chest compressions compared with Two-Finger(TF) in an instrumented infant manikin. Whether this translates to differences in blood flow, such as carotid arterial blood flow(CABF), has not been evaluated. We hypothesized that TT-CPR generates higher CABF and Coronary Perfusion Pressure(CPP) compared with TF-CPR in a neonatal swine cardiac arrest model. METHODS: Twelve anesthetized & ventilated piglets were randomized after 3 min of untreated VF to receive either TT-CPR or TF-CPR by PALS certified rescuers delivering a compression rate of 100/min. The primary outcome, CABF, was measured using an ultrasound transonic flow probe placed on the left carotid artery. CPP was calculated and end-tidal CO2(ETCO2) was measured during CPR. Data(mean ± SD) were analyzed and p-value ≤0.05 was considered statistically significant. RESULTS: Carotid artery blood flow (% of baseline) was higher in TT-CPR (66.2 ± 35.4%) than in the TF-CPR (27.5 ± 10.6%) group, p = 0.013. Mean CPP (mm Hg) during three minutes of chest compression for TT-CPR was 12.5 ± 15.8 vs. 6.5 ± 6.7 in TF-CPR, p = 0.41 and ETCO2 (mm Hg) was 29.0 ± 7.4 in TT-CPR vs. 20.7 ± 5.8 in TF-CPR group, p = 0.055. CONCLUSION: TT-CPR achieved more than twice the CABF compared with TF-CPR in a piglet cardiac arrest model. Although CPP and ETCO2 were higher during TT-CPR, these parameters did not reach statistical significance. This study provides direct evidence of increased blood flow in infant swine using TT-CPR and further supports that TT chest compression is the preferred method for CPR in infants.