DEPDC5 plays a vital role in epilepsy: Genotypic and phenotypic features in cohort and literature

Chunyu Gu; Xinping Wei; Dandan Yan; Yingzi Cai; Dong Li; Jianbo Shu; Chunquan Cai

doi:10.1002/epd2.20223

DEPDC5 plays a vital role in epilepsy: Genotypic and phenotypic features in cohort and literature

Epileptic Disord. 2024 May 16. doi: 10.1002/epd2.20223. Online ahead of print.

Authors

Chunyu Gu¹, Xinping Wei², Dandan Yan¹, Yingzi Cai¹, Dong Li², Jianbo Shu¹, Chunquan Cai¹

Affiliations

¹ Tianjin Pediatric Research Institute, Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China.
² The Medical Department of Neurology, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China.

PMID: 38752894
DOI: 10.1002/epd2.20223

Abstract

Objective: DEPDC5 emerges to play a vital role in focal epilepsy. However, genotype-phenotype correlation in DEPDC5-related focal epilepsies is challenging and controversial. In this study, we aim to investigate the genotypic and phenotypic features in DEPDC5-affected patients.

Methods: Genetic testing combined with criteria published by the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG/AMP), was used to identify pathogenic/likely pathogenic variants in DEPDC5 among the cohort of 479 patients with focal epilepsy. Besides, the literature review was performed to explore the genotype-phenotype correlation and the penetrance in DEPDC5-related focal epilepsies.

Results: Eight unrelated probands were revealed to carry different pathogenic/likely pathogenic variants in DEPDC5 and the total prevalence of DEPDC5-related focal epilepsy was 1.67% in the cohort. Sixty-five variants from 28 studies were included in our review. Combined with the cases reported, null variants accounted for a larger proportion than missense variants and were related to unfavorable prognosis (drug resistance or even sudden unexpected death in epilepsy; χ² = 5.429, p = .020). And, the prognosis of probands with developmental delay/intellectual disability or focal cortical dysplasia was worse than that of probands with simple epilepsy (χ² = -, p = .006). Besides, the overall penetrance of variants in DEPDC5 was 68.96% (231/335).

Significance: The study expands the variant spectrum of DEPDC5 and proves that the DEPDC5 variant plays a significant role in focal epilepsy. Due to the characteristics of phenotypic heterogeneity and incomplete penetrance, genetic testing is necessary despite no specific family history. And we propose to adopt the ACMG/AMP criteria refined by ClinGen Sequence Variant Interpretation Working Group, for consistency in usage and transparency in classification rationale. Moreover, we reveal an important message to clinicians that the prognosis of DEPDC5-affected patients is related to the variant type and complications.

Keywords: DEPDC5; focal epilepsy; genetic testing; genotype–phenotype correlation; penetrance.

Abstract

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