Chromosome 22q11 deletion and other chromosome aberrations in cases with cleft palate, congenital heart defects and/or mental disability. A survey based on the Danish Facial Cleft Register.

Abstract

Velo-cardio-facial syndrome (VCFS) is a syndrome associated with haplo-insufficiency of genes at chromosome 22q11. The syndrome has a broad phenotypic spectrum including multiple anomalies, of which cleft palate (CP), congenital heart defects (CHD), and mental disabilities are among the most common. Hence, a high prevalence of 22q11 deletions should be expected among cases with a combination of CP and CHD or/and mental disability. In Denmark a population-based database comprising 2301 CP cases born 1936-1987 has been established. Cases with CP and CHD or/and mental disabilities were selected from the register. By using public registers 39 living cases were identified, among whom 15 agreed to blood sampling and testing for 22q11 deletion using FISH (fluorescence in situ hybridization) analysis. Four deletion cases were identified. Using a polymorphic microsatellite marker (D22S264), two cases were shown to be de novo deletions of maternal origin. The parental origin in the two other cases could not be determined. The patients ranged in age from 7 to 40 years. All patients had mental impairment, and one also showed signs of paranoid psychosis. Two cases had CHD. Furthermore, five cases previously karyotyped had other chromosomal aberrations. The study shows that facial cleft registers are an obvious source for identifying a group of patients with a high risk of VCFS and chromosome 22q11 microdeletion. These individuals as well as their families can benefit from genetic counselling.