AUTHOR=Chen Li-juan , You Zhong-min , Chen Wen-hong , Yang Si , Feng Chun-chen , Wang Hai-yong , Wang Ting , Zhu Yuan-yuan TITLE=Helsmoortel–van der Aa syndrome in a Chinese pediatric patient due to ADNP nonsense mutation: A case report JOURNAL=Frontiers in Pediatrics VOLUME=11 YEAR=2023 URL=https://www.frontiersin.org/journals/pediatrics/articles/10.3389/fped.2023.1122513 DOI=10.3389/fped.2023.1122513 ISSN=2296-2360 ABSTRACT=Background

Helsmoortel–van der Aa syndrome, also known as ADNP syndrome, is a condition that causes developmental delay, language impairment, autism spectrum, and variable extraneurologic features. It is caused by heterozygous mutations in the ADNP gene on chromosome 20q13. Most of the genetic causes of Helsmoortel–van der Aa syndrome have been reported are as de novo nonsense or frameshift stop mutations in exon 5 of ADNP gene, while fewer truncating variants were discovered in exons 4 and the 5′ end of exon 5.

Methods

In our study, a 4-year-old female Chinese patient was reported with delayed psychomotor development, language impairment, ataxia, anxiety, aggressive behavior, and congenital heart defect. Trio whole exome sequencing and copy number variation sequencing were performed.

Results

A novel de novo heterozygous pathogenic mutation c.568C > T (p.Gln190Ter) was identified in the ADNP gene of the proband. His unaffected parents did not have the variant. According to the American College of Medical Genetics (ACMG) guidelines, c.568C > T was classified as “pathogenic”.

Conclusion

Our report indicated that c.568C > T (p.Gln190Ter) in ADNP gene is the cause of abnormal development of the nervous system, congenital heart disease and strabismus, broadening the spectrum of ADNP gene mutations associated with Helsmoortel–van der Aa syndrome.