[Familial aggregation and sibling heritability in Kashin-Beck disease]

To explore the family aggregation and the role of hereditary factors in the pathogenesis of Kashin-Beck disease (KBD).

With a stratified sampling method, the general population of 14 villages of Linyou County were studied, from whom 225 KBD probands were selected using systematic sampling at the rate of (1/2). A total of 304 siblings of the probands were ascertained, and in these sibling pairs, the segregation ratio, heritability in different age groups and weighted mean heritability of the siblings were estimated using the methods of Li-Mantel-Grart and Falconer.

The KBD distribution scope in the KBD families exceeded the scope of binomial distribution (P<0.001), suggesting obvious family aggregation. The prevalence rate in the siblings of the KBD pedigree was 19.41% (59/304), significantly higher than that in the 14 KBD villages [10.90% (1180/10823), chi2=21.62, P<0.001]. The segregation ratio and heritability in the siblings of the KBD pedigrees were 0.061 and 28.61%, respectively.

As a polygenetic inheritance disease, KBD exhibits obvious familial aggregation, and genetic susceptibility accounts for (1/4) of the risk factors for KBD.