Zadik–Barak–Levin syndrome

Zadik–Barak–Levin syndrome (ZBLS) is a rare congenital disorder that manifests in humans. This syndrome presents a spectrum of abnormalities primarily rooted in embryonic development, particularly affecting the mesodermal-ectodermal midline. The key features of this disorder include primary hypothyroidism, cleft palate, hypodontia, and characteristics of ectodermal dysplasia.

Etiology and Pathogenesis

ZBLS arises from embryonic disruptions during the formation phase of the mesodermal-ectodermal midline. This disruption is considered pivotal in the syndrome's etiology, though the exact molecular mechanisms remain under investigation.

Signs and Symptoms

Patients diagnosed with ZBLS may exhibit a range of the following clinical features:

• Anodontia or oligodontia, characterized by a complete absence or significantly fewer teeth than normal.
• Presence of a cleft palate.
• Depressed nasal bridge.
• Dry skin, typical of ectodermal dysplasia.
• Ectopic, absent (agenesis), or underdeveloped (hypoplastic) thyroid gland.
• Presence of epibulbar dermoid.
• Frontal bossing or pronounced forehead.
• Hypertelorism - Increased distance between the eyes.
• Clinical hypothyroidism.
• Spinal curvature (lordosis).
• Enlarged tongue (macroglossia).
• Abnormally small head circumference (microcephaly).
• A notably small (micrognatia) or recessed (retrognatia) jaw.
• Excess amniotic fluid during pregnancy (polyhydramnios).
• Disproportionately short stature or dwarfism.
• Sparse to absent scalp hair.
• Eye abnormalities including squint or paresis of ocular muscles.
• Protrusion of the navel (umbilical hernia).

Diagnosis

The diagnosis of ZBLS is primarily based on clinical examination and symptom presentation. Radiographic imaging and genetic testing may also aid in the diagnosis and differentiation from other syndromes with overlapping symptoms.

Management

Management strategies for ZBLS are multifaceted and often involve a multidisciplinary approach, catering to the specific needs and symptoms of each individual patient. Therapeutic measures may include hormone replacement for hypothyroidism, dental interventions for dental anomalies, and surgical corrections for structural abnormalities like cleft palate.