Down Syndrome with Complete Atrioventricular Septal Defect, Hypertrophic Cardiomyopathy, and Pulmonary Vein Stenosis

Abstract

C ongenital heart disease (CHD) is found in 40% of infants with Down syndrome but in only 0.3% of children who have normal chromosomes.1 In Down syndrome, ventricular septal defect and atrioventricular septal defect (AVSD) are typical malformations. Transient hypertrophic cardiomyopathy (HCM) in neonates has typically been attributed to maternal diabetes mellitus and has infrequently been reported in association with CHD. Atrioventricular septal defect is often associated with chromosomal aberration, whereas HCM is thought to be secondary to specific gene mutations. We found just one reported case of congenital HCM and AVSD in an infant with Down syndrome.2 Here, we report the case of a neonate who had Down syndrome with HCM, complete AVSD, and pulmonary vein (PV) stenosis, and we discuss the relevant medical literature. Case ReportA male infant (twin B) from a dichorionic diamniotic pregnancy was born at our hospital. The 38-year-old mother underwent a cesarean section at 33 weeks of gestation because of uteroplacental insufficiency and intrauterine growth restriction. The infant's birth weight was 3 lb 6 oz, and his Apgar scores were 8 at 1 min and 9 at 5 min. Routine antenatal ultrasonographic results had raised suspicion of AVSD; other findings were the absence of a nasal bone and a poorly visible stomach in twin B. At 26 weeks of gestation, a prenatal echocardiogram had shown a common atrioventricular (AV) canal defect in twin B and no cardiac defects in twin A. No antenatal genetic tests were performed.The initial physical examination revealed a neonate who was small for his gestational age and had Down facies, single palmar crease, and mild hypotonia. Cardiovascular examination revealed a normal precordium, no cyanosis, a normal S 1 , and a loud S 2 (P2 component) with no murmur. The peripheral pulses were well palpable. The liver was palpable 2 cm below the costal margin. A chest radiograph showed an enlarged cardiac silhouette. A 12-lead electrocardiogram showed sinus rhythm, left-axis deviation, and possible biventricular hypertrophy. A transthoracic echocardiogram (TTE) showed a common AV canal defect (Rastelli type A), a thick ventricular septum, a large pa tent ductus arteriosus, and a patent foramen ovale. A postnatal chromosomal analysis revealed 47, XY, +21 (trisomy 21).Serial TTEs were obtained during the infant's hospital stay. At 3 months, a TTE showed complete AVSD and severe asymmetric septal hypertrophy (Fig. 1), as well as left ventricular midcavitary obstruction (peak gradient, 25 mmHg). There was no systolic anterior motion of the mitral valve. Results of hemodynamic catheterization included pulmonary venous desaturation of 88% on the left due to chronic lung dis-

Comprehensive maternal serum proteomics identifies the cytoskeletal proteins as non-invasive biomarkers in prenatal diagnosis of congenital heart defects

“…studied maternal serum proteome changes between the first and third trimester of pregnancy, and observed that the serum concentration of gelsolin (belong to the cytoskeleton family) changed during pregnancy 23 . Besides, a cluster of cytoskelatal proteins were found to be less abundant in the serum of women with Down syndrome-pregnancies and preeclampsia 13 14 24 , and 40% of Down syndrome fetuses have CHDs 25 . All above indicated that dysregulation of these cytoskeletal proteins might reflect disturbance of embryonic development, thus, deep exploration of these protein changes in maternal serum may facilitate prenatal diagnosis of pregnancy-related disorders.…”

Undiagnosed Congenital Heart Defects as a Cause of Sudden, Unexpected Death in Children

“…In our case series, the most commonly detected defect was AVSD (11 individuals), also known as “AV canal,” which, in four cases, was observed in children with Down syndrome (trisomy 21). In fact, it is known that AVSDs and other cardiac defects are often associated with chromosomal aberrations, such as in trisomy 21 . Therefore, infants with Down syndrome usually have an echocardiogram to look for CHDs prior to discharge from the hospital.…”

Association of Hypoparathyroidism-Retardation-Dysmorphism Syndrome (HRD) with Down syndrome

“…Upward slanted palpebral fissures, single transverse palmar creases, wide gap between the first and second toes, and hypotonia are strongly suggesting the possibility of Down syndrome [7]. Complete atrioventricular septal defect, which affects approximately 3% of all patients who have congenital heart disease, tends to be associated with down syndrome [8]. Neonatal hypoparathyroidism is relatively common, and occurring usually as a transient condition associated with well-defined risk factors such as prematurity, perinatal asphyxia, and maternal diabetes [3].…”