CHARGE syndrome associated with de novo (I1460Rfs*15) frameshift mutation of CHD7 gene in a patient with arteria lusoria and horseshoe kidney

Exp Ther Med. 2020 Jul;20(1):479-485. doi: 10.3892/etm.2020.8683. Epub 2020 Apr 23.

Abstract

CHARGE syndrome is an autosomal dominant condition caused by mutations in the chromodomain helicase DNA binding protein 7 (CHD7) gene. The present study reported on the case of a 16-month-old female with plurimalformative syndrome, whose etiology was identified by clinical whole-exome sequencing (WES) analysis. Clinical and follow-up assessments identified multiple craniofacial dysmorphisms, congenital defects and functional symptoms, including dysphagia and Marcus Gunn jaw winking synkinesis. Trio-WES analysis was performed for the patient and their parents and the presence of CHARGE syndrome was further indicated using single-molecule real-time sequencing. A de novo pathogenic variant, c.4379_4380del (p.Ile1460Argfs*15), was identified in exon 19 of the CHD7 gene, which resulted in a premature translational stop signal. Trio-WES analysis was used for further investigation, indicating that neither of the patient's parents had the mutation and confirming its de novo nature. To the best of our knowledge, the case of the present study was the first reported case of CHARGE syndrome in Romania with congenital defects including an aberrant right subclavian artery and a horseshoe kidney. CHARGE syndrome was diagnosed in the patient based on the pathogenic mutation in the CHD7 gene. To the best of our knowledge, the present case report is the first to suggest that the CHD7 gene variant is associated with CHARGE syndrome.

Keywords: CHARGE syndrome; CHD7 gene; arteria lusoria; frameshift mutation; horseshoe kidney.