SNP Shot: Genomic Insights

Pfeiffer syndrome is a genetic condition defined by craniosynostosis, where certain skull bones fuse together too early. This premature fusion restricts normal skull growth, altering the head and facial structure. The syndrome also impacts the bones of the hands and feet.

The distinctive facial features associated with Pfeiffer syndrome arise from this early skull bone fusion. The abnormal bone growth can cause prominent, widely spaced eyes, a high forehead, an underdeveloped upper jaw, and a nose with a beaked appearance. Hearing loss affects over half of children with Pfeiffer syndrome, and dental issues are frequently observed.

Individuals with Pfeiffer syndrome typically exhibit broad thumbs and big toes that deviate away from the other digits. Short fingers and toes (brachydactyly) are also commonly seen, and webbing or fusion between digits (syndactyly) might be present.

Pfeiffer syndrome is categorized into three subtypes. Type 1, or classic Pfeiffer syndrome, manifests with the symptoms detailed earlier. Most individuals with type 1 Pfeiffer syndrome possess typical intelligence and a normal lifespan. Types 2 and 3 represent more severe forms, often involving complications with the nervous system. The premature skull bone fusion can hinder brain development, resulting in developmental delays and other neurological issues. Furthermore, those with type 2 or 3 may experience bone fusion (ankylosis) in the elbow or other joints, restricting movement, as well as facial and airway abnormalities that can lead to life-threatening respiratory problems. Type 2 is differentiated from type 3 by the presence of a cloverleaf-shaped head, resulting from a more widespread fusion of skull bones.

Inheritance:

The inheritance pattern of Pfeiffer syndrome is autosomal dominant, meaning that only one copy of the mutated gene in each cell is enough to cause the disorder.