Strategic validation of variants of uncertain significance in ECHS1 genetic testing

© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ..

BACKGROUND: Enoyl-CoA hydratase short-chain 1 (ECHS1) is an enzyme involved in the metabolism of branched chain amino acids and fatty acids. Mutations in the ECHS1 gene lead to mitochondrial short-chain enoyl-CoA hydratase 1 deficiency, resulting in the accumulation of intermediates of valine. This is one of the most common causative genes in mitochondrial diseases. While genetic analysis studies have diagnosed numerous cases with ECHS1 variants, the increasing number of variants of uncertain significance (VUS) in genetic diagnosis is a major problem.

METHODS: Here, we constructed an assay system to verify VUS function for ECHS1 gene. A high-throughput assay using ECHS1 knockout cells was performed to index these phenotypes by expressing cDNAs containing VUS. In parallel with the VUS validation system, a genetic analysis of samples from patients with mitochondrial disease was performed. The effect on gene expression in cases was verified by RNA-seq and proteome analysis.

RESULTS: The functional validation of VUS identified novel variants causing loss of ECHS1 function. The VUS validation system also revealed the effect of the VUS in the compound heterozygous state and provided a new methodology for variant interpretation. Moreover, we performed multiomics analysis and identified a synonymous substitution p.P163= that results in splicing abnormality. The multiomics analysis complemented the diagnosis of some cases that could not be diagnosed by the VUS validation system.

CONCLUSIONS: In summary, this study uncovered new ECHS1 cases based on VUS validation and omics analysis; these analyses are applicable to the functional evaluation of other genes associated with mitochondrial disease.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:60

Enthalten in:

Journal of medical genetics - 60(2023), 10 vom: 13. Okt., Seite 1006-1015

Sprache:

Englisch

Beteiligte Personen:

Kishita, Yoshihito [VerfasserIn]
Sugiura, Ayumu [VerfasserIn]
Onuki, Takanori [VerfasserIn]
Ebihara, Tomohiro [VerfasserIn]
Matsuhashi, Tetsuro [VerfasserIn]
Shimura, Masaru [VerfasserIn]
Fushimi, Takuya [VerfasserIn]
Ichino, Noriko [VerfasserIn]
Nagatakidani, Yoshie [VerfasserIn]
Nishihata, Hitomi [VerfasserIn]
Nitta, Kazuhiro R [VerfasserIn]
Yatsuka, Yukiko [VerfasserIn]
Imai-Okazaki, Atsuko [VerfasserIn]
Wu, Yibo [VerfasserIn]
Osaka, Hitoshi [VerfasserIn]
Ohtake, Akira [VerfasserIn]
Murayama, Kei [VerfasserIn]
Okazaki, Yasushi [VerfasserIn]

Links:

Volltext

Themen:

EC 4.2.1.17
Enoyl-CoA Hydratase
Genetic testing
Genetic variation
Journal Article
Molecular diagnostic techniques
RNA-Seq
Research Support, Non-U.S. Gov't

Anmerkungen:

Date Completed 25.09.2023

Date Revised 27.09.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1136/jmg-2022-109027

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM355595028