Estimation of Modified Concordance Ratio in Sib-Pairs: Effect of Consanguinity on the Risk of Congenital Heart Diseases

Family studies are widely used for research into genetic and environmental influences on human traits. In this paper, we establish statistical methodology for the estimation of a new measure of sib similarity with respect to dichotomous traits measured on each member of within family sib-pair. We call this parameter "excess risk." For inference problems involving a single sample, we construct a large sample confidence interval on the concerned parameter. It has long been suspected that consanguinity is a risk factor for many genetic defects. Therefore, we establish a procedure to test the significance of the difference between excess risk parameters in a sample of consanguineous marriages and another sample of non-consanguineous marriages. We apply the methodology to data from a hospital-based congenital heart defects registry in Saudi Arabia, a population in which consanguinity is quite common.

Left Ventricular Mechanics in Patients with Abnormal Origin of the Left Main Coronary Artery from the Pulmonary Trunk Late after Successful Repair

Our aim was to evaluate left ventricular (LV) mechanics by using speckle tracking echocardiography (STE) in asymptomatic patients with abnormal origin of the left main coronary artery from the pulmonary trunk (ALCAPA), late after successful repair, in the presence of LV ejection fraction (EF) >50%.Objective: Our aim was to evaluate left ventricular (LV) mechanics by using speckle tracking echocardiography (STE) in asymptomatic patients with abnormal origin of the left main coronary artery from the pulmonary trunk (ALCAPA), late after successful repair, in the presence of LV ejection fraction (EF) >50%. Methods: We studied 30 ALCAPA patients (median age 4 years, range 1-25 years, NYHA class I, LVEF >50%) and 16 healthy age- and sex-matched controls (median age 5 years, range 1-25 years). All underwent standard echocardiographic evaluation and STE. Results: LV dimensions and LVEF (63.6 +/- 8.2% vs. 64.1 +/- 5.1%, p = 0.826) were not different between patients and controls. Diastolic parameters were significantly abnormal in our patients versus controls (E/e' average: 11.9 5.8 vs. 6.6 +/- 3.0, p = 0.0014). Global LV longitudinal strain was significantly lower in ALCAPA patients versus controls (-17.6 +/- 3.5% vs. 23.4 +/- 3.1%, p < 0.0001). LV torsion (9.1 +/- 4.9 vs. 11.9 +/- 3.3, p = 0.046) was significantly impaired in ALCAPA patients. Conclusions: After successful repair in asymptomatic ALCAPA patients, despite an LVEF >50%, diastolic function, LV longitudinal deformation and LV torsion remain impaired. We suggest including a detailed study of the diastolic function and cardiac mechanics in the clinical follow-up of these patients to identify the subgroup of patients at higher risk. (C) 2016 S. Karger AG, Base