[A case with autosomal dominant mental retardation type 5 due to de novo SYNGAP1 variant]

Zhonghua Yi Xue Yi Chuan Xue Za Zhi. 2020 Jun 10;37(6):661-664. doi: 10.3760/cma.j.issn.1003-9406.2020.06.016.
[Article in Chinese]

Abstract

Objective: To investigate the clinical and genetic features of a Chinese girl featuring mental retardation, intellectual disability, language development delay and epilepsy.

Methods: G-banded chromosomal karyotyping was carried out for the child. Genomic DNA of the patient and her parents was extracted and subjected to high-throughput sequencing. The results were analyzed with bioinformatic tools and validated by Sanger sequencing.

Results: The karyotype of the child was ascertained as 46,XX. Sequencing result showed that she has carried a de novo heterozygous c.1861C>T (p.R621X) variant of the SYNGAP1 gene.

Conclusion: The nonsense variant c.1861C>T (p.R621X) of the SYNGAP1 gene probably underlies the disease in this child. Above result has enabled genetic diagnosis and counseling for her family.

Publication types

  • Case Reports

MeSH terms

  • Arthrogryposis*
  • Child
  • Developmental Disabilities
  • Female
  • Heterozygote
  • High-Throughput Nucleotide Sequencing
  • Humans
  • Intellectual Disability*
  • ras GTPase-Activating Proteins / genetics

Substances

  • SYNGAP1 protein, human
  • ras GTPase-Activating Proteins