EP09.13: Sex ratio of non‐syndromic cleft lip and/or palate in Hong Kong Chinese

Abstract

To analyse the sex ratio of non-syndromic cleft lip and/or palate (NSCL/P) in Hong Kong Chinese. All cases of NSCL/P delivered in a teaching hospital in Hong Kong from 2001–2014 were reviewed. The sex ratio for different kinds of NSCL/P was compared using chi square test. During the study period, 87,989 (45,562 male and 42,427 female) live births were delivered. There were 96 cases of NSCL/P, 50 male and 46 female. The incidence of NSCL/P was 1:916 live births (1:911 male and 1:922 female). There were 54 (56%) cleft lip and palate, 24 (25%) cleft lip only and 18 (19%) cleft palate only. Male was more frequently affected than female, with male: female (M:F) ratio of 1.1:1. This feature of male predominance was observed in cleft lip only, cleft lip and palate and cleft lip with or without cleft palate, with M:F ratio of 1.7:1, 1.3:1 and 1.4:1 respectively. However, the sex ratio was reversed in cleft palate only, with M:F ratio of 0.3:1. The difference is statistically significant (p = 0.0175). Non-syndromic cleft lip with or without palate is more common in male while non-syndromic cleft palate only is more common in female. This may indicate that they represent two different entities with totally different genetic basis and environmental trigger. Researchers working on NSCL/P may need to make a distinction between the two entities.