EP07.33: Binder phenotype: prenatal diagnosis, management and postnatal outcome – insights from a case series

Binder phenotype (BP) is a developmental disorder of the anterior part of the maxilla and nasal complex and is characterised by short nose with a flat nasal bridge, short columella, acute nasolabial angle, perialar flatness, convex upper lip, and tendency to a class III malocclusion. The etiology of BP is heterogeneous with diverse features and outcomes. We present 7 fetuses diagnosed prenatally with BP, their varied etiology, management, and postnatal outcomes. BP was suspected when the prenatal 2D ultrasound identified a low flat nasal bridge in the profile view of the face in the second trimester ultrasound. Nasofrontal angle (NFA) was measured between the nasal bone and the frontal bone in the midsagittal plane when the fetal neck was in mild flexion. Short columella with flattened tip and alar wings was also demonstrated. 3D imaging was done to complement 2D image findings. The phenotype was compared postnatally with a 2-year follow-up. All 7 fetuses had dysmorphic facies characterised by verticalisation of nasal bone with short columella, flat nasal tip and alar wings, and increased nasofrontal angle suggestive of Binder phenotype. 2D and 3D images were obtained. The etiologies in our case series were physiognomy, intractable vomiting leading to Vit K deficiency, maternal overlap syndrome, Trisomy 21 and an unclassified cause.2 pregnancies underwent medical termination while 5 pregnancies were delivered at term. The outcome of the 5 fetuses as assessed clinically was considered optimal at 2-year follow-up. The diagnosis of facial dysmorphism such as Binder phenotype brings a lot of apprehension and agony in the parents amounting to multiple tests and counselling sessions. Physiognomy which is the normal familial appearance should be considered before concluding whether the observed feature is normal or pathological. Accurate diagnosis, adequate testing, and dedicated counselling will help in the prevention of needless termination of pregnancies.