Longitudinal growth and height velocity of Japanese children with Down's syndrome

Area of Science:

• Pediatrics
• Genetics
• Human Growth and Development

Background:

• Down's syndrome is a genetic disorder associated with characteristic physical features and developmental differences.
• Growth patterns in children with Down's syndrome can vary and may differ from typical growth trajectories.

Purpose of the Study:

• To establish the natural growth patterns of Japanese children diagnosed with Down's syndrome.
• To create standard growth and height velocity curves specific to this population.

Main Methods:

• Longitudinal height data were collected from 85 Japanese children (43 males, 42 females) from birth to final height.
• Semi-longitudinal standard growth curves and height velocity curves were developed based on the collected data.

Main Results:

• Final mean heights for males and females with Down's syndrome were 153.2 cm and 141.9 cm, respectively, corresponding to -3.0 and -2.8 SD for Japanese standards.
• Mean peak height velocities were 8.9 cm/year for males and 7.5 cm/year for females, occurring at ages 11.6 and 10.2 years, respectively.
• Pre-pubertal height was approximately -2 SD below normal, with pubertal growth starting about one year earlier and peak velocity being 1.3-1.4 cm/year lower than in normal children.

Conclusions:

• Children with Down's syndrome show significantly reduced final height compared to the general population.
• The pubertal growth spurt in Down's syndrome initiates earlier but exhibits diminished peak velocity.
• These findings provide crucial data for monitoring and managing growth in Japanese children with Down's syndrome.