Additional patient with del(12)(q21.2q22): further evidence for a candidate region for cardio-facio-cutaneous syndrome?

Cardio-facio-cutaneous (CFC) syndrome is characterized by a distinct facial appearance, cardiac defects, ectodermal anomalies and developmental delay. Recently, we reported a 19-month-old girl with phenotypic manifestations consistent with the CFC syndrome who had an interstitial deletion of the long arm of chromosome 12, del(12)(q21.2q22), implicating a possible locus for CFC syndrome. Here, we report an additional patient with a cytogenetically identical interstitial deletion: 47,XYY,del(12)(q21.2q22). To further characterize this deletion we used microarray-based comparative genomic hybridization (array CGH). Array CGH confirmed both the deletion and the second Y chromosome. The deletion on chromosome 12q spanned at least 14 Mb as indicated by the positions on the genome sequence of the 4 BAC clones included in the deletion. While the proband did not have the classic features of CFC, he had some dysmorphic craniofacial characteristics, ectodermal anomalies and moderate developmental delay which were suggestive of CFC syndrome; however, this patient did not have classical CFC. The phenotypic differences between the two del(12)(q21.2q22) patients may be due to variability in the expression of the syndrome, or this deletion may present as a syndrome with overlapping features. Alternatively, the phenotypic differences may result from discordance at the molecular level, which may yield a critical minimal region of deletion for CFC. The region 12q21.2 --> q22 remains a possible candidate region for CFC syndrome. Additional characterization of these and other CFC patients may confirm and further refine this candidate region.