What Is Frontonasal Dysplasia?
Frontonasal dysplasia is a rare disease that results from abnormal development of the head and face before birth. Symptoms often vary, however more common symptoms include wide spaced eyes, a widow's peak, and a broad nose. Less common features include eye abnormalities, missing the connection between the two halves of the brain (agenesis of the corpus callosum), hearing loss, and undescended testicles in males (cryptorchidism). Most people with the dysplasia have normal intelligence. There are three main types of frontonasal dysplasia that are distinguished by their genetic causes and symptoms. Other frontonasal dysplasia syndromes have also been described. Frontonasal dysplasia is very rare, with around 100 cases reported in the literature.
Type 1 frontonasal dysplasia is caused by mutations (changes) in the ALX3 gene, type 2 is caused by mutations in the ALX4 gene, and type 3 is caused by mutations in the ALX1 gene. Type 1 and type 3 frontonasal dysplasia are inherited in an autosomal recessive manner, whereas frontonasal dysplasia type 2 is inherited in an autosomal dominant manner. Diagnosis is often first suspected when a baby has features consistent with frontonasal dysplasia. X-rays and genetic testing may be used to confirm the diagnosis. Treatment of the disease may include one or more surgeries to correct certain birth defects, as well as early intervention and special education services, if needed.
Source: Genetic and Rare Diseases (GARD) Information Center