Nablus mask-like facial syndrome

Overview

Nablus mask-like facial syndrome (NMLFS) is an extremely rare genetic disorder first reported in 2000, characterized primarily by distinctive facial features that give the appearance of a rigid, mask-like face. Named after the city of Nablus in the West Bank where the initial case was identified, this syndrome is associated with multiple congenital anomalies, intellectual disability, and growth retardation. The facial characteristics are so striking and consistent that they form the core diagnostic feature, though other systemic anomalies may also be present. Due to its rarity, less than a dozen confirmed cases have been reported in medical literature.

Causes

Nablus mask-like facial syndrome is caused by a genetic microdeletion on chromosome 8, specifically in the 8q22.1 region. This microdeletion is typically de novo, meaning it occurs as a new genetic alteration in the affected individual and is not inherited from the parents. The deleted segment contains genes believed to be crucial for craniofacial development and neurodevelopment. The exact gene or combination of genes responsible for the syndrome's specific features has not been fully elucidated, but the loss of these genes disrupts normal developmental pathways, leading to the observable clinical signs.

Symptoms

The hallmark symptom of Nablus mask-like facial syndrome is the distinct facial appearance, which includes a set of tightly drawn facial features giving a rigid, expressionless look. Other symptoms and features include:

• Tight, inelastic facial skin with little to no movement (mask-like appearance)

• Blepharophimosis (narrowing of the eye opening)

• Telecanthus (increased distance between the inner corners of the eyes)

• Flat or depressed nasal bridge

• Prominent, broad nasal tip

• Small mouth and micrognathia (small jaw)

• Low-set ears or abnormal ear shape

• Growth retardation and short stature

• Developmental delay or intellectual disability

• Hypertrichosis (excess body hair)

• Congenital anomalies affecting the hands or feet

The severity and combination of symptoms can vary, even among individuals with the same chromosomal deletion.

Diagnosis

Diagnosis of Nablus mask-like facial syndrome is based on clinical evaluation and genetic testing. The following steps are typically involved:

• Clinical assessment: Observation of characteristic facial features and associated anomalies by a pediatric geneticist.

• Cytogenetic testing: High-resolution chromosomal microarray or comparative genomic hybridization (CGH) to detect microdeletion in 8q22.1.

• Molecular genetic testing: May be performed to further narrow down the affected genes within the deleted segment.

Due to the syndrome’s rarity, many cases may go undiagnosed or be misdiagnosed as other craniofacial syndromes unless a comprehensive genetic analysis is performed.

Treatment

There is no cure for Nablus mask-like facial syndrome, and treatment is primarily symptomatic and supportive. A multidisciplinary approach is often required, including:

• Speech and language therapy to assist with communication difficulties due to facial rigidity and developmental delay.

• Physical and occupational therapy to address motor delays and improve daily functioning.

• Educational support tailored to the individual’s cognitive level and developmental needs.

• Genetic counseling for families to understand the nature and recurrence risks of the disorder.

• Medical or surgical intervention for associated anomalies, such as corrective surgery for eyelid or ear deformities, if necessary.

Management is best coordinated by a team that includes a pediatrician, geneticist, developmental specialist, and other relevant healthcare providers.

Prognosis

The prognosis for individuals with Nablus mask-like facial syndrome varies depending on the severity of associated anomalies and the level of intellectual disability. While the facial features are static, other challenges such as developmental delays and learning difficulties can impact long-term outcomes. Life expectancy is not well-documented due to the limited number of reported cases, but survival into adulthood is possible with appropriate medical care and support.

With early intervention and tailored supportive therapies, individuals with NMLFS may achieve a better quality of life. Continued documentation of cases and research into the genetic basis of the disorder may lead to improved diagnostic and management strategies in the future.