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

Abstract

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.

Keywords: CHD3 gene; Child; Developmental delay; Snijders Blok-Campeau syndrome.

图1. 患儿特殊面容 眼距宽，鼻梁宽而低平，耳位低。

图2. 患儿及其父母CHD3基因Sanger测序图 患儿存在CHD3基因c.3872G>A(p.G1291D)杂合错义突变，患儿父亲和母亲均无该突变，箭头所示为突变位置。

图3. CHD3蛋白结构图与本病例突变位置