Identification of one novel CHD7 mutation in a patient from China with atypical CHARGE syndrome

CHARGE syndrome in nine patients from China

CHARGE syndrome (CS) is a multiple congenital anomalies condition with the majority of cases caused by dominant loss-of-function mutations of the CHD7 gene. It is clinically characterized by coloboma of the eyes, heart defects, choanal atresia, retardation of growth and/or development, genital and/or urinary anomalies and ear malformations associated with deafness and vestibular disorder(s). This case series reported nine molecularly confirmed Chinese CS patients from nine unrelated families in Hong Kong. Clinical phenotype and facial features of these nine Chinese CS patients together with four previously reported Chinese patients were reviewed. Typical presentations like coloboma and choanal atresia were not universally present. The prevalence of choanal atresia in these Chinese CS patients was found to be significantly lower than that in previous cohorts of other ethnic groups. This report highlighted the existence of phenotypic variation of CS among different ethnicities and suggested that a high index of suspicion is necessary for diagnosis of CS in Chinese patients.

A novel frameshift mutation of CHD7 in a Japanese patient with CHARGE syndrome

CHARGE syndrome is a rare autosomal dominant developmental disorder involving multiple organs. CHD7 is a major causative gene of CHARGE syndrome. We performed targeted-exome sequencing using a next-generation sequencer for molecular diagnosis of a 4-month-old male patient who was clinically suspected to have CHARGE syndrome, and report a novel monoallelic mutation in CHD7, NM_017780.3(CHD7_v001):c.2966del causing a reading frameshift [p.(Cys989Serfs*3)].