RESUMO
Pre-mRNA splicing factors are crucial in regulating transcript diversity, by removing introns from eukaryotic transcripts, an essential step in gene expression. Splicing of pre-mRNA is catalyzed by spliceosomes. CWC27 is a cyclophilin associated with spliceosome, in which genetic defects of its components have been linked to spliceosomopathies with clinical phenotypes including skeletal developmental defects, retinitis pigmentosa (RP), short stature, skeletal anomalies, and neurological disorders. We report two siblings (male and female) of Mexican descent with a novel homozygous frameshift variant in CWC27 and aim to highlight the cardinal features among the previously described 12 cases as well as expand the currently recognized phenotypic spectrum. Both siblings presented with a range of ocular and extraocular manifestations including novel features such as solitary kidney and tarsal coalition in the male sibling, together with gait abnormalities, and Hashimoto's thyroiditis in the female sibling. Finally, we highlight ectodermal involvement including sparse scalp hair, eyebrows and lashes, pigmentary differences, nail dysplasia, and dental anomalies as a core phenotype associated with the CWC27 spliceosomopathy.
Assuntos
Precursores de RNA , Retinose Pigmentar , Feminino , Humanos , Masculino , Ciclofilinas/genética , Ciclofilinas/metabolismo , Peptidilprolil Isomerase/genética , Retinose Pigmentar/genética , Precursores de RNA/genética , Splicing de RNA/genética , Spliceossomos/genética , México/etnologiaRESUMO
Patients with rare, undiagnosed, or genetic disease (RUGD) often undergo years of serial testing, commonly referred to as the "diagnostic odyssey". Patients in resource-limited areas face even greater challenges-a definitive diagnosis may never be reached due to difficulties in gaining access to clinicians, appropriate specialists, and diagnostic testing. Here, we report on a collaboration of the Illumina iHope Program with the Foundation for the Children of the Californias and Hospital Infantil de Las Californias, to enable deployment of clinical whole genome sequencing (cWGS) as first-tier test in a resource-limited dysmorphology clinic in northern Mexico. A total of 60 probands who were followed for a suspected genetic diagnosis and clinically unresolved after expert examination were tested with cWGS, and the ordering clinicians completed a semi-structured survey to investigate change in clinical management resulting from cWGS findings. Clinically significant genomic findings were identified in 68.3% (n = 41) of probands. No recurrent molecular diagnoses were observed. Copy number variants or gross chromosomal abnormalities accounted for 48.8% (n = 20) of the diagnosed cases, including a mosaic trisomy and suspected derivative chromosomes. A qualitative assessment of clinical management revealed 48.8% (n = 20) of those diagnosed had a change in clinical course based on their cWGS results, despite resource limitations. These data suggest that a cWGS first-tier testing approach can benefit patients with suspected genetic disorders.