An unclassified variant of CHD7 activates a cryptic splice site in a patient with CHARGE syndrome.

CHARGE syndrome is a rare autosomal dominant disease that is typically caused by heterozygous CHD7 mutations. A de novo variant in a CHD7 splicing acceptor site (NM_017780.3:c.7165-4A>G) was identified in a Japanese boy with CHARGE syndrome. This variant has been considered to be an "unclassified variant" due to its position outside the consensus splicing sites. In this study, abnormal splicing derived from this known variant was confirmed by cDNA sequencing.