Article

The genetic/environmental etiology of Scheuermann's
disease is unclear. We estimated the heritability of the disease using an
etiological model adjusted for sex and time of diagnosis, and examined whether
the prevalence of Scheuermann's disease was constant over time. METHODS: 46,418
twins were sent a questionnaire about health and disease. Of these, 75% returned
the questionnaire and 97% answered the question "Have you been diagnosed as
having Scheuermann's disease by a doctor?" RESULTS: Responders included 11,436
complete pairs of twins. Data were analysed using classical twin modeling
methods. Tetrachoric correlations were used to decide which etiological model to
fit. The best-fitting model was the AE model. Heritability was 0.74 (95% CI:
0.65-0.81), while variance explained by environmental factors was 0.26 (95% CI:
0.19-0.35). A threshold of 2.1 (95% CI: 1.9-2.2) was calculated, corresponding to
a prevalence of 1.9% (95% CI: 1.3-2.8) for women. Regression coefficients for age
and sex were 0.000 (95% CI: -0.003 to 0.002) and -0.32 (95% CI: -0.42 to -0.23).
INTERPRETATION: We found a heritability of 0.74 in Scheuermann's disease. The
threshold in men was lower than in women, corresponding to a male prevalence that
was almost twice that of females. We found no change in the prevalence of
Scheuermann's disease throughout the 50-year age span that we examined.

Langue : ANGLAIS