Objective: Congenital heart defects occur in approximately 50% of children with Down syndrome and they contribute considerably to morbidity and mortality. The aim of this study is to investigate the prevalence, classification, and survival of congenital heart defects in Down syndrome. Materials and Methods: About 1731 Down syndrome patients who underwent echocardiography between 1986 and 2022 were evaluated. The median follow-up duration was 8.7 years (range 1-35.8 years). Congenital heart defect was grouped as cyanotic and acyanotic. Results: Among the 1731 patients, 52.1% had congenital heart defects. Congenital heart defect was significantly more common in females than males. The most common cardiac defect was ventricular septal defect (35%), followed by atrial septal defect (31.8%), atrioventricular septal defect (23.4%), tetralogy of Fallot (5%), and patent ductus arteriosus (3.6%). In the follow-up, 43.2% of atrial septal defect, 17.8% of ventricular septal defect, and a total of 20% of congenital heart defects were closed spontaneously. About 34.4% of congenital heart defect was corrected by cardiac surgery/intervention. Five-year survival rate was 97.4% in patients without congenital heart defects, whereas it was 95.6% in mild congenital heart defects and 86.1% in moderate to severe congenital heart defects. There was no relationship between consanguinity, parental age, maternal disease, folic acid supplementation before/during pregnancy, gestational age, birth weight, and congenital heart defects. Neuromotor development was similar in patients with and without congenital heart defects. Conclusion: We demonstrated that almost half of the patients had congenital heart defects; ventricular septal defect was the most common congenital heart defect type. This study is valuable in terms of the largest single-center study describing the classification, prognostic factors, and survival of Down syndrome patients with congenital heart defect from Turkey. Cite this article as: Uludağ Alkaya D, Öztürk B, Yüksel Ülker A, et al. Congenital heart defects and outcome in a large cohort of Down syndrome: A single-center experience from Turkey. Turk Arch Pediatr. 2023;58(5):473-479.

The Beckwith–Wiedemann spectrum (BWSp) ranges from isolated lateralized overgrowth (ILO) to classic phenotypes. In this broad clinical spectrum, an epigenetic alteration on chromosome 11p15.5 can be detected. The risk for embryonal tumors is high, especially in patients with lateralized overgrowth (LO). The aim of this study is to investigate epigenetic alterations in 11p15.5 and tumor risk in 87 children with LO. The methylation level of 11p15.5 was examined in the blood of all patients and in skin samples or buccal swabs from 40 patients with negative blood tests; 63.2% of patients were compatible with the ILO phenotype, 18.4% were atypical, and 18.4% were classic. The molecular diagnosis rate was 81.2% for the atypical and classic phenotypes, and 10.9% for the ILO phenotype. In patients with epigenetic alterations, LO was statistically significantly more severe than in test negatives. Tumors developed in six (6.9%) of the total 87 patients with LO; four belonged to the atypical or classical phenotype (12.5%) and two to ILO (3.5%). Three of the four patients with atypical/classical phenotypes had pUPD11, one had IC1-GOM alteration, and two ILO patients were negative. We conclude that LO patients should be monitored for tumor risk even if their epigenetic tests are negative.

Objective:Williams syndrome is caused by a microdeletion at 7q11.23 and is characterized by a distinctive face, cardiovascular disease, and intellectual disability with a specific cognitive and behavioral profile. This study aims to evaluate the clinical features and obtain important information that can guide early diagnoses and correct follow-up. Materials and Methods: The study included 78 patients whose diagnoses were confirmed by fluorescent in situ hybridization. Facial features, anthropometric measurements, and neurocognitive, endocrine, and urinary system evaluations were obtained from the medical records, and photographs of the patients were evaluated retrospectively. Results: The most common complaints at admission were cardiovascular disease and atypical face. The mean age at admission was 39 ± 4.8 months. The mean age of patients presenting with atypical face was 41 ± 5.6 months, while it was 11 ± 3.1 months in patients presenting with cardiovascular disease. Short nose/bulbous nasal type with anteverted nares and periorbital fullness, which are diagnostic facial features, were present in all patients in the infantile/ early childhood period. 80% of the patients had cardiovascular disease; supravalvular aortic stenosis (53.8%) and peripheral pulmonary artery stenosis (41%) were the most common cardiac anomalies.Intel lectu al/de velop menta l disability was present in 75.6% of the patients. Behavioral disorders including autism spectrum disorder and attention deficit hyperactivity disorder were detected in 50% of our patients. Hypersensitivity to loud and/or sudden sounds was present in all patients. Conclusion: We highlighted that recognition of facial findings is important for early diagnosis, especially in patients without cardiovascular disease. The frequency of cardiovascular, endocrinological, renal anomalies, and intellectual disab ility /deve lopme ntal delay was described that provide valuable information in the follow-up of patients. Cite this article as: Bozlak S, Uludağ Alkaya D, Kasap B, et al. A large Turkish cohort of Williams syndrome: The evaluation of facial, cardiovascular, and neuropsychiatric features. Turk Arch Pediatr. 2023;58(2):182-188.