Cleft lip and/or palate in a low-resource province in China

Abstract

Cleft lip and/or palate (CLP) is a polygenically inherited defect, which means that its chance of recurrence within the same family is higher than in the general population. The pattern of inheritance is not decided by a pair of alleles. Rather, it is due to the combinational effect of several sets of genes within the environment. When the probability of inheriting a genetic disease is higher than 60%, this is considered a high chance of inheritance. The probability of inheriting CLP is 76%. Thus, it is advisable to seek genetic counseling before marriage or pregnancy to effectively minimize the prevalence of CLP within the Chinese society.

Women from 28 weeks of pregnancy forward and their newborns until 7 days after birth were investigated at 17 hospitals in Guizhou province, China, whether the child was live-born or stillborn or whether fetal death had occurred. The study was conducted from January 1, 1996, until December 31, 2004. Over the 9-year study period, the mean overall prevalence of birth defects was 120.94 per 10,000 births, which was found to be statistically significant by the χ2 test (P < 0.001). Of all birth defects CLP was the most prevalent, with a mean prevalence of 22.63 per 10,000 births, which was statistically significant (P < 0.001). There was no obvious trend for change within these 9 years (Table 1). Nonsyndrome types accounted for 87.17% of CLP cases in Guizhou province, with a male-to-female ratio of 1.65:1.