Novel mutation in the ASXL3 gene in a Chinese boy with microcephaly and speech impairment:A case report  

作　　者：Jin-Rong Li Zhuo Huang You Lu Qiao-Yun Ji Ming-Yan Jiang Fan Yang 

机构地区：[1]Department of Pediatrics,West China Second University Hospital,Sichuan University,Chengdu 610041,Sichuan Province,China [2]Department of Ministry of Education,Key Laboratory of Birth Defects and Related Diseases of Women and Children(Sichuan University),Chengdu 610041,Sichuan Province,China

出　　处：《World Journal of Clinical Cases》2020年第24期6465-6472,共8页世界临床病例杂志

基　　金：Supported by the Health andFamily Planning Commission ofSichuan Province, No. 150106.

摘　　要：BACKGROUND Bainbridge-Ropers syndrome (BRPS) is a severe disorder characterized by failureto thrive, facial dysmorphism, and severe developmental delay. BRPS is caused bya heterozygous loss-of-function mutation in the ASXL3 gene. Due to limitedknowledge of the disease and lack of specific features, clinical diagnosis of thissyndrome is challenging. With the use of trio-based whole exome sequencing, weidentified a novel ASXL3 mutation in a Chinese boy with BRPS and performed aliterature review.CASE SUMMARY A 3-year-old Chinese boy was referred to our hospital due to progressivepostnatal microcephaly and intellectual disability with severe speech impairmentfor 2 years. His other remarkable clinical features were shown as follows: Facialdysmorphism, feeding difficulties, poor growth, motor delay, and abnormalbehavior. For the proband, regular laboratory tests, blood tandem massspectrometry, urine gas chromatographic mass spectrometry, karyotype, hearingscreening, and brain magnetic resonance imaging were performed, with negativeresults. Therefore, for the proband and his unaffected parents, trio-based wholeexome sequencing and subsequent validation by Sanger sequencing wereperformed. A novel nonsense variant in exon 11 of the ASXL3 gene (c.1795G>T;p.E599*) was detected, present in the patient but absent from his parents. Takinginto account the concordant phenotypic features of our patient with reportedBRPS patients and the detected truncated variant located in the known mutationalcluster region, we confirmed a diagnosis of BRPS for this proband. Therehabilitation treatment seemed to have a mild effect.CONCLUSION In this case, a novel nonsense mutation (c.1795G>T, p.E599*) in ASXL3 gene wasidentified in a Chinese boy with BRPS. This finding not only contributed to bettergenetic counseling and prenatal diagnosis for this family but also expanded thepathogenic mutation spectrum of ASXL3 gene and provided key information forclinical diagnosis of BRPS.

关 键 词：Bainbridge-Ropers syndrome ASXL3 mutation Whole-exome sequencing Case report 

分 类 号：R725.9[医药卫生—儿科]