Snijders Blok-Campeau syndrome caused by CHD3 gene mutation: a case report.

A one-year and two-month old girl indicated large head circumference, widely spaced eyes, narrow palpebral fissures, strabismus on the right eye, broad and low nasal bridge and low-set ears. She had knee over extension and foot eversion on both sides while standing with help. She also had hypotonia and was not able to stand or walk independently. She can say "ma ma" unconsciously. In the neuropsychological developmental assessment, delayed development was shown on gross motor function, fine movement, adaptive capacity, speech and social behavior function. A de novo heterozygous mutation, c.3872G>A(p.G1291D), likely pathogenic, was detected in the CHD3 gene via the next generation sequencing. Snijders Blok-Campeau syndrome was confirmed. It is an extremely rare disease with only 60 cases reported globally. This case expands the CHD3 gene mutation sites and suggests that rare diseases need to be considered and genetic tests should be performed in children with intellectual developmental delay and abnormal facial features, so as to help early diagnosis. Citation.