Neurologic and gastrointestinal dysfunction in cardio-facio-cutaneous syndrome: identification of a severe phenotype

Controversy exists over the distinction between cardio-facio-cutaneous (CFC) syndrome and Noonan syndrome (NS). Several authors have suggested that they are different phenotypes of the same condition. We present the cases of two patients with CFC syndrome to show that it is a distinct condition with a unique combination of findings and a more complex natural history. These patients, both girls, were born with signs of fetal edema following pregnancies complicated by polyhydramnios. Each has short stature with relative macrocephaly; fuzzy, sparse hair; and the typical craniofacial features, including a square forehead. Both have heart abnormalities, failure to thrive, and severe feeding problems requiring gastrostomy. They are markedly hypotonic and developmentally delayed. They show signs of frequent eyelid fluttering and have oral aversion, tactile hypersensitivity, and sensory integration abnormalities. Keratosis pilaris, the characteristic skin symptom, is also present in both patients. In a review we identified 56 cases of CFC syndrome. We scored these cases by 10 clinical criteria and identified a subset with a specific, severe phenotype distinct from that of NS. The serious neurologic and gastrointestinal complications, in addition to the skin abnormalities and characteristic facies in this group, clearly separate these patients from the mildly affected ones, most of whom appear to have NS or another syndrome. We discuss the differences between the severe CFC phenotype and those of overlapping conditions. We set forth stringent diagnostic criteria for CFC syndrome, the initial step toward identifying a molecular basis for this condition.