Cardio-facio-cutaneous syndrome and gastrointestinal defects: report on a newborn with 19p13.3 deletion including the MAP 2 K2 gene.

BACKGROUND

Cardio-facio-cutaneous syndrome (CFCS) belongs to RASopathies, a group of conditions caused by mutations in genes encoding proteins of the rat sarcoma/mitogen-activated protein kinase (RAS/MAPK) pathway. It is a rare syndrome, with about 300 patients reported. Main clinical manifestations include facial dysmorphisms, growth failure, heart defects, developmental delay, and ectodermal abnormalities. Mutations (mainly missense) of four genes (BRAF, MAP 2 K1, MAP 2 K2, and KRAS) have been associated to CFCS. However, whole gene deletions/duplications and chromosomal microdeletions have been also reported. Specifically, 19p13.3 deletion including MAP 2 K2 gene are responsible for cardio-facio-cutaneous microdeletion syndrome, whose affected subjects show more severe phenotype than CFCS general population.

CASE PRESENTATION

Hereby, we report on a female newborn with prenatal diagnosis of omphalocele, leading to further genetic investigations through amniocentesis. Among these, array comparative genomic hybridization (a-CGH) identified a 19p13.3 microdeletion, spanning 1.27 Mb and including MAP 2 K2 gene. Clinical features at birth (coarse face with dysmorphic features, sparse and friable hair, cutaneous vascular malformations and hyperkeratotic lesions, interventricular septal defect, and omphalocele) were compatible with CFCS diagnosis, and further postnatal genetic investigations were not considered necessary. Soon after discharge, at around 1 month of life, she was readmitted to our Neonatal Intensive Care Unit due to repeated episodes of vomiting, subtending a hypertrophic pyloric stenosis (HPS) which was promptly identified and treated.

CONCLUSIONS

Our report supports the 19p13.3 microdeletion as a contiguous gene syndrome, in which the involvement of the genes contiguous to MAP 2 K2 may modify the patients' phenotype. It highlights how CFCS affected subjects, including those with 19p13.3 deletions, may have associated gastrointestinal defects (e.g., omphalocele and HPS), providing further data on 19p13.3 microdeletion syndrome, and a better characterization of its genomic and phenotypic features. The complex clinical picture of such patients may be worsened by additional, and even precocious, life-threatening conditions like HPS. Clinicians must consider, anticipate and/or promptly treat possible medical and surgical complications, with the aim of reducing adverse outcomes. Extensive diagnostic work-up, and early, continuous, and multidisciplinary follow-up, as well as integrated care, are necessary for the longitudinal clinical evolution of any single patient.