Elisa Rahikkala, Jonna Komulainen-Ebrahim, Jussi-Pekka Tolonen, Sandra Vorimo, Maria Suo-Palosaari, Päivi Vieira, Johanna Piispala, Johanna Uusimaa, Katri Pylkäs, Tuomo Mantere
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引用次数: 0
Abstract
Background: X-linked recessive type 3 Charcot-Marie-Tooth (CMTX3) is a rare subtype of childhood-onset CMT. To date, all reported CMTX3 patients share a common founder 78 kb insertion from chromosome 8 into the Xq27.1 palindrome region.
Methods: We conducted patient-parent trio optical genome mapping (OGM) on a male patient presenting with clinically diagnosed Dejerine-Sottas disease for whom initial standard diagnostic genetic tests, including whole-genome sequencing (WGS), yielded negative results.
Results: OGM analysis revealed a maternally inherited interchromosomal insertion from chromosome region 7q31.1 into Xq27.1. Coupled with manual reassessment of WGS data, this confirmed the molecular diagnosis of atypical CMTX3 and showed that the 122.4 kb inserted fragment contained DLD and partially LAMB1. Subsequent analyses confirmed that the rearrangement had arisen de novo in the proband's mother.
Conclusion: We report the second Xq27.1 rearrangement associated with CMTX3, providing novel clinical insights into its phenotypic and genotypic spectrum. Our findings highlight the importance of including genomic rearrangement analysis of Xq27.1 in standard diagnostic pipelines for childhood-onset CMT. Given the overlap in polyneuropathy phenotypes resulting from insertions from chromosomes 7 and 8 into the same Xq27.1 palindrome region, the pathogenic mechanism underlying peripheral neuropathy in CMTX3 likely involves dysregulation of genes within this region.
期刊介绍:
Molecular Genetics & Genomic Medicine is a peer-reviewed journal for rapid dissemination of quality research related to the dynamically developing areas of human, molecular and medical genetics. The journal publishes original research articles covering findings in phenotypic, molecular, biological, and genomic aspects of genomic variation, inherited disorders and birth defects. The broad publishing spectrum of Molecular Genetics & Genomic Medicine includes rare and common disorders from diagnosis to treatment. Examples of appropriate articles include reports of novel disease genes, functional studies of genetic variants, in-depth genotype-phenotype studies, genomic analysis of inherited disorders, molecular diagnostic methods, medical bioinformatics, ethical, legal, and social implications (ELSI), and approaches to clinical diagnosis. Molecular Genetics & Genomic Medicine provides a scientific home for next generation sequencing studies of rare and common disorders, which will make research in this fascinating area easily and rapidly accessible to the scientific community. This will serve as the basis for translating next generation sequencing studies into individualized diagnostics and therapeutics, for day-to-day medical care.
Molecular Genetics & Genomic Medicine publishes original research articles, reviews, and research methods papers, along with invited editorials and commentaries. Original research papers must report well-conducted research with conclusions supported by the data presented.