Under-recognition of 22q11.2 deletion in adult Chinese patients with conotruncal anomalies: implications in transitional care.

[22q11.2 deletion syndrome]

22 q 11 .2 deletion syndrome (22 q 11 .2 DS ) is a multi-systemic disorder with high phenotypic variability . Under-diagnosis in adults is common and recognition of facial dysmorphic features can be affected by age and ethnicity . This study aims to determine the prevalence of undiagnosed 22 q 11 .2 DS in adult Chinese patients with conotruncal anomalies and to delineate their facial dysmorphisms and extra -cardiac manifestations . We recruited consecutively 156 patients with conotruncal anomalies in an adult congenital heart disease (CHD ) clinic in Hong Kong and screened for 22 q 11 .2 DS using fluorescence-PCR and fluorescence in -situ hybridization . Assessment for dysmorphic features was performed by a cardiologist at initial screening and then by a clinical geneticist upon result disclosure . Clinical photographs were taken and childhood photographs collected . Eighteen patients (11 .5 %) were diagnosed with 22 q 11 .2 DS , translating into 1 previously unrecognized diagnosis of 22 q 11 .2 DS in every 10 adult patients with conotruncal anomalies . While dysmorphic features were detected by our clinical geneticist in all patients , only two -thirds were considered dysmorphic by our cardiologist upon first assessment . Evolution of facial dysmorphic features was noted with age . Extra -cardiac manifestations included velopharyngeal incompetence or cleft palate (44 %), hypocalcemia (39 %), neurodevelopmental anomalies (33 %), thrombocytopenia (28 %), psychiatric disorders (17 %), epilepsy (17 %) and hearing loss (17 %). We conclude that under-diagnosis of 22 q 11 .2 DS in Chinese adults with conotruncal defects is common and facial dysmorphic features may not be reliably recognized in the setting of adult CHD clinic , referral for genetic evaluation and molecular testing for 22 q 11 .2 DS should be offered to patients with conotruncal defects .