SNP Shot: Genomic Insights

Cardiofaciocutaneous (CFC) syndrome is a rare genetic condition that affects multiple areas of the body, notably the heart, face, skin, and hair. Individuals with CFC syndrome typically experience developmental delays and intellectual disability, which usually range from moderate to severe.

Heart defects are common in individuals with CFC syndrome. Frequently observed heart conditions include pulmonic stenosis (a narrowing of the valve that controls blood flow from the heart to the lungs), atrial septal defect (a hole between the heart's upper chambers), and hypertrophic cardiomyopathy (a condition where the heart muscle thickens and weakens).

Distinctive facial features are another hallmark of CFC syndrome. These characteristics may include a high forehead that narrows at the temples, a short nose, widely spaced eyes (hypertelorism), eyes that slant downward, droopy eyelids (ptosis), a small chin, and low-set ears. The overall facial appearance is often described as broad and long, sometimes with "coarse" features.

Skin abnormalities are almost universally present in individuals with CFC syndrome. Common skin issues include dry, rough skin; dark moles (nevi); wrinkled palms and soles; and keratosis pilaris, a condition characterized by small bumps on the arms, legs, and face. Thin, dry, curly hair, along with sparse or absent eyelashes and eyebrows, are also frequently observed.

Infants with CFC syndrome often exhibit weak muscle tone (hypotonia), feeding difficulties, and failure to thrive (inability to grow and gain weight as expected). Additional features that may be present in children and adults with CFC syndrome include an unusually large head (macrocephaly), short stature, vision problems, and seizures.

The symptoms of CFC syndrome can resemble those of Costello syndrome and Noonan syndrome, two other genetic disorders. These three conditions are differentiated by their specific genetic causes and the unique patterns of signs and symptoms they present. However, distinguishing between them can be challenging, particularly in infancy. Unlike Costello syndrome, which carries a significantly increased risk of cancer, cancer does not seem to be a prominent feature of CFC syndrome.

Inheritance:

CFC syndrome is typically considered an autosomal dominant condition. This means that having only one copy of the altered gene in each cell is sufficient to cause the disorder. CFC syndrome most often arises from new gene mutations and occurs in individuals with no family history of the condition. In some reported cases, an affected individual has inherited the condition from a parent who also has CFC syndrome.