Reyes-Silva Carlos, Gallardo-Vizuete Joseline, Guzmán-Acán Judith, Jaramillo-Koupermann Gabriela, Cabrera-Andrade Alejandro
Unidad de Genética, Hospital de Especialidades Eugenio Espejo, Quito 170403, Ecuador.
Posgrado de Endocrinología, Universidad de Las Américas, Quito 170125, Ecuador.
Genes (Basel). 2025 Apr 25;16(5):490. doi: 10.3390/genes16050490.
: Dyggve-Melchior-Clausen syndrome (DMC) is a rare autosomal recessive skeletal dysplasia characterized by dwarfism, coarse facial features, and intellectual disability. Caused by loss-of-function variants in the gene, which encodes dymeclin, DMC is predominantly reported in consanguineous populations but remains poorly studied in South America. : We report a 21-year-old Ecuadorian male with clinical features suggestive of DMC. Comprehensive clinical, radiological, and genetic evaluations were conducted, including clinical exome sequencing and Sanger sequencing, followed by an in silico analysis to assess the structural and functional consequences of the identified variant. : Exome sequencing identified a homozygous c.1878delA (p.Lys626fs) frameshift variant in the gene, which was confirmed by Sanger sequencing as inherited from heterozygous parents. Variants of uncertain significance were detected in other skeletal dysplasia-related genes but did not correlate with the phenotype. A comprehensive review of reported variants was also conducted. : This report documents the first case of DMC in Ecuador and the second in South America, expanding the global understanding of DMC's genetic diversity. It underscores the value of next-generation sequencing in rare disease diagnostics and highlights the critical need for inclusive genomic research in underrepresented populations to improve the understanding of genetic heterogeneity and rare disease epidemiology.
迪格维-梅尔基奥尔-克劳森综合征(DMC)是一种罕见的常染色体隐性遗传性骨骼发育不良疾病,其特征为侏儒症、面部特征粗糙以及智力障碍。DMC由编码动力蛋白的基因功能丧失性变异引起,主要在近亲婚配人群中报道,但在南美洲的研究仍然较少。
我们报告了一名21岁的厄瓜多尔男性,其临床特征提示患有DMC。我们进行了全面的临床、放射学和遗传学评估,包括临床外显子组测序和桑格测序,随后进行了计算机分析,以评估所鉴定变异的结构和功能后果。
外显子组测序在该基因中鉴定出一个纯合的c.1878delA(p.Lys626fs)移码变异,桑格测序证实该变异是从杂合子父母遗传而来。在其他骨骼发育不良相关基因中检测到意义不明确的变异,但与表型无关。我们还对已报道的变异进行了全面综述。
本报告记录了厄瓜多尔首例DMC病例以及南美洲第二例DMC病例,扩展了全球对DMC基因多样性的认识。它强调了下一代测序在罕见病诊断中的价值,并突出了在代表性不足的人群中开展包容性基因组研究以增进对遗传异质性和罕见病流行病学理解的迫切需求。