The 18q deletion syndrome (18q-) is a multiple-anomaly disorder associated with mental retardation, white matter anomalies in the brain, growth hormone deficiency, congenital aural atresia, orofacial cleft (OFC), and palate abnormalities. The aims of this study were to determine the frequency of different forms of OFC in 18q- individuals: cleft palate with or without cleft lip (CP/L), cleft lip (CL), and palate abnormalities. We also sought to map a potential critical region for OFC within chromosome 18q22.3 region.
The study presents an overview of selected 18q- individuals from 11 published reports and one presented poster.
The frequency of CP/L and CL among 18q- individuals is about 25%; when high/arched palate cases are included, the frequency rises to about 43%.
Orofacial abnormalities are characteristic features of 18q- syndrome patients and potential CP/L critical region could be assumed at 18q22.3 between markers D18S879 and D18S1141. In addition, gene deficient mouse models for Sall3 or Tshz1 genes, which are located at the 18q22.3 critical region, displayed palate abnormality phenotype.