Publication:

Incidence of hypocalcemia in pediatric patients with Down syndrome: a prospective observational study

Background Down syndrome (DS) is the most frequently occurring chromosomal condition, affecting from 1 in 700 to 1 in 1,500 live-born babies. Children with DS are at high risk of developing metabolic and endocrine abnormalities such as thyroid dysfunction, diabetes mellitus, obesity, short stature, vitamin D deficiency, low bone mineral density, and gonadal dysfunction than the general population. However, the prevalence and persistence of hypocalcemia in early childhood remain underexplored. This study aimed to assess the incidence and significance of hypocalcemia in pediatric patients with DS aged 1 to 5 years.

Methods A prospective observational study was conducted on 55 children with genetically confirmed DS, aged 1 to 5 years. Serum calcium, phosphate, and parathyroid hormone (PTH) levels were measured at baseline and followed up for over 12 months. Vitamin D levels and dietary calcium intake were also assessed. Statistical analysis was performed to compare hypocalcemia prevalence with general pediatric population data.

Results Hypocalcemia (serum calcium <8.5 mg/dl) was observed in 21 out of 55 children (38.2%), which was significantly higher than in the general pediatric population (p<0.001). Hypoparathyroidism was identified in 11 cases (20%), with persistently low PTH levels. Vitamin D deficiency was present in 27 children (49%), contributing to secondary hypocalcemia in some cases. Clinical symptoms: Hypotonia (35%), delayed motor milestones (22%), and seizures (7%).

Conclusions Hypocalcemia is significantly more prevalent in children with DS aged 1 to 5 years, with hypoparathyroidism and vitamin D deficiency being major contributing factors. Routine screening and early calcium and vitamin D supplementation may help prevent complications in this vulnerable population.