Nasomaxillary Hypoplasia: A Case of Binder Phenotype

27-year-old primigravida with spontaneous conception presented for routine anomaly ultrasound scan. There is no significant family history of birth defects or consanguinity.

Sagittal 2D ultrasound views of the fetal profile show severe midfacial hypoplasia (Figure 1). Flattening of maxilla with verticalized hypoplastic nasal bone is seen with levelling of frontal angle (Figure 2).

No signs of other associated facial anomalies were seen.

3D image of the face shows abnormal midface (Figure 3).

Background

Binder syndrome is a rare multi-phenotypic heterogeneous entity characterized by nasomaxillary hypoplasia. It is known to be associated with multiple other etiologies like trisomy 21, chondrodysplasia punctata (CDP), advanced maternal age, maternal intake of coumarin-based anticoagulants during pregnancy, vitamin K deficiency in early embryogenesis, systemic lupus erythematosus, etc [1]. Detection of Binder phenotype during routine antenatal ultrasonogram mandates further evaluation to look for chromosomal aberrations or genetic etiologies.

Clinical Perspective

Binder Syndrome is mainly asymptomatic, found incidentally on routine antenatal scanning. There have been reported cases of associations with hyperemesis gravidarum [2].

Identification of abnormal fetal facial proportions, as in this phenotype is an important clue to look for its associations with multiple factors [3]. Pregnancies with proven genetic or chromosomal abnormalities need counseling and multidisciplinary approach.

Imaging Perspective

Prenatal imaging features include midface hypoplasia and absent nasal spine which creates a flat facial profile with depression of the nasal bridge secondary to deficient horizontal growth of the maxilla. Other features include short nasal and columella formation, leveling of frontal angle, flat nasolabial angle and peri-alar flattering [1,4]. This flat facial profile is the primary abnormality on which the diagnosis of Binder syndrome depends. It is a soft sonographic clue towards underlying presence of chromosomal/ genetic disorders.

Outcome

The parents decided to not go forward with karyotyping and terminated the pregnancy after counseling. Postmortem examination confirmed the facial dysmorphism - flat midface with mild hypertelorism.  Isolated midface hypoplasia has a good prognosis. But all cases require surgical correction with grafting for adequate mastication [5].

Take Home Message / Teaching Points

Identification of Binder phenotype is the key toward the diagnosis of the multiple associations including genetic/ chromosomal abnormalities. 

Written informed patient consent for publication has been obtained.