Zheng F, Lin Z, Hu Y, Shi X, Zhao Q, Lin Z. Identification of a Novel Non-Canonical Splice-Site Variant in
ABCD1.
J Clin Med 2023;
12:jcm12020473. [PMID:
36675402 PMCID:
PMC9863105 DOI:
10.3390/jcm12020473]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/27/2022] [Accepted: 12/27/2022] [Indexed: 01/09/2023] Open
Abstract
Cerebral adrenoleukodystrophy (CALD) is a fatal genetic disease characterized by rapid, devastating neurological decline, with a narrow curative treatment window in the early stage. Non-canonical splice-site (NCSS) variants can easily be missed during genomic DNA analyses, and only a few of them in ABCD1 have been explored. Here, we studied a Chinese patient with clinical features similar to those of early-stage CALD but with a negative molecular diagnosis and a sibling who had presumably died of CALD. Trio-based whole-exome sequencing (trio-WES) and RNA sequencing (RNA-Seq) revealed a novel hemizygote NCSS variant c.901-25_901-9 del in ABCD1 intron 1, resulting in a complex splicing pattern. The in vitro minigene assay revealed that the c.901-25_901-9 del construct contained two aberrant transcripts that caused skipping of exon 2 and a small 48-bp deletion on left of the same exon. We identified a novel NCSS variant, that extends the spectrum of the known ABCD1 variants, and demonstrated the pathogenicity of this gene variant. Our findings highlight the importance of combining RNA-Seq and WES techniques for prompt diagnosis of leukodystrophy with NCSS variants.
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