Copy number variations on chromosome 4q26-27 are associated with Cantu syndrome

Abstract

Background: Cantu syndrome is a rare condition which is characterized clinically by hypertrichosis, cardiomegaly and bone abnormalities. Inherited hypertrichoses are very rare human disorders whose incidence has been estimated as low as 1 in 1 billion. The genetic basis of hypertrichosis is largely unknown, and currently no single gene has been directly implicated in its pathogenesis, although position effects have been reported.

Methods: We analyzed the DNA of a patient with Cantu syndrome on the Affymetrix Cytogenetics Whole-Genome 2.7M array for copy number variations (CNVs). We then performed genomic copy number quantification using qPCR, and finally we performed gene expression analysis in the hair follicle for the genes lying within and around the region of the duplication.

Results: We identified a 375 kb duplication on chromosome 4q26-27. The duplication region encompassed three genes, which included MYOZ2, USP53 and FABP2. MYOZ2 and USP53 are known to be highly expressed in the cardiac muscle, and we found that USP53 is expressed in the hair follicle.

Conclusion: We propose that CNVs involving chromosome 4q26-27 may be associated with Cantu syndrome. CNVs spanning several genes may help define the molecular basis of syndromes which have unrelated clinical features.