Retrospective Study of Obesity in Children with Down Syndrome.

OBJECTIVES: To assess whether children with Down syndrome in the US are at an increased risk for obesity, we determined the obesity prevalence and analyzed obesity development throughout childhood in a cohort of children with Down syndrome. In addition, we analyzed a comorbidity that is associated with Down syndrome and obesity, obstructive sleep apnea syndrome (OSAS). STUDY DESIGN: This study was a retrospective chart review that evaluated 303 children ages 2 through 18 years with a diagnosis of Down syndrome. All children were patients at Cincinnati Children's Hospital Medical Center with multiple height and weight measurements. To determine obesity burden, the rate of obesity was compared with a local control cohort using contingency tables. Change in obesity rate through time was determined with mixed models. Association of obesity with OSAS was determined with contingency tables. RESULTS: We evaluated 303 individuals, 47.8% of whom were obese (body mass index ≥95th percentile for age and sex). This was significantly higher than the general pediatric population, which had a 12.1% obesity rate (P < .0001). Body mass index z-scores did not change markedly over time (P = .40). The majority of children with Down syndrome also had OSAS (74.0% of the 177 children who had polysomnography studies). However, OSAS risk was elevated in obese children (risk ratio = 2.4, P = .0015). CONCLUSIONS: Our results indicate that children with Down syndrome are at a substantial risk for obesity and OSAS. These findings support the need for more aggressive weight management in early childhood and throughout the lifespan.

Homozygous missense variant in BMPR1A resulting in BMPR signaling disruption and syndromic features.

BACKGROUND: The bone morphogenetic protein (BMP) pathway is known to play an imperative role in bone, cartilage, and cardiac tissue formation. Truncating, heterozygous variants, and deletions of one of the essential receptors in this pathway, Bone Morphogenetic Protein Receptor Type1A (BMPR1A), have been associated with autosomal dominant juvenile polyposis. Heterozygous deletions have also been associated with cardiac and minor skeletal anomalies. Populations with atrioventricular septal defects are enriched for rare missense BMPR1A variants. METHODS: We report on a patient with a homozygous missense variant in BMPR1A causing skeletal abnormalities, growth failure a large atrial septal defect, severe subglottic stenosis, laryngomalacia, facial dysmorphisms, and developmental delays. RESULTS: Functional analysis of this variant shows increased chondrocyte death for cells with the mutated receptor, increased phosphorylated R-Smads1/5/8, and loss of Sox9 expression mediated by decreased phosphorylation of p38. CONCLUSION: This homozygous missense variant in BMPR1A appears to cause a distinct clinical phenotype.