Wiedemann-Rautenstrauch syndrome is an extremely rare autosomal recessive progeroid disorder closely linked to mutations in POLR3A. Here, we report a case of a 4-year-old female patient carrying a novel compound-heterozygous variant in POLR3A. In addition to the classic Wiedemann-Rautenstrauch syndrome features-progressive diffuse alopecia, growth retardation, and abnormal white matter development-the patient presented with severe anemia and skin laxity, phenotypes not previously described in Wiedemann-Rautenstrauch syndrome. RT-qPCR analysis of skin tissue demonstrated a significant downregulation of POLR3A mRNA expression (p < 0.01). To our knowledge, this is the first report implicating an intronic POLR3A variant in Wiedemann-Rautenstrauch syndrome in the Chinese population, expanding both the mutational and phenotypic spectra of the disorder and underscoring its clinical heterogeneity.

Induced pluripotent stem cells (iPSCs) derived from patients with premature aging disorders are widely regarded as a foundation for both the study of fundamental aging mechanisms and preclinical testing of anti-aging therapies. The most well-studied is Hutchinson-Gilford progeria syndrome (HGPS), which is caused by a lamin A gene mutation. Comparing the progeroid phenotype in cell models of distinct premature aging syndromes is critical for identifying early and common aging hallmarks. In this study, using a non-integrative episomal approach we reprogrammed iPSCs from cells of a patient suffering from Wiedemann-Rautenstrauch Syndrome (WRS), which is caused by bi-allelic pathogenic mutations of the RNA polymerase III subunit A gene (POLR3A). In parallel, an iPSC line with the classic HGPS caused by a lamin A mutation was obtained. HGPS and WRS patient fibroblasts showed similar signs of cellular aging; however, unlike HGPS, the causal link between the premature aging phenotype and WRS driving mutations is unclear. RNA polymerase III is required for the transcription of small nuclear RNAs and being a target of TORC1 (Target of Rapamycin kinase Complex 1), it plays a role in longevity and aging in model organisms. Whereas lamin A is downregulated in iPSCs, allowing for regeneration of HGPS iPSCs, we found that POLR3A is upregulated during reprogramming. Enhanced expression of mutant POLR3A in WRS iPSCs led to nucleolus abnormalities and telomerase RNA component (TERC) sequestration in the nucleoli in WRS iPSCs. WRS iPSCs may be an important model for developing new therapeutic approaches affecting premature aging of stem cells.

Wiedemann-Rautenstrauch syndrome (WRS) is a rare neonatal progeroid disorder primarily associated with pathogenic variants in POLR3A. However, the pathogenicity of certain variants remains unclear. Here, we report a WRS case carrying the POLR3A c.2707G > A (p.Gly903Arg) variant and explore its potential role in disease pathogenesis through in silico predictive and structural modeling analyses. Evolutionary conservation analysis, along with functional impact predictions from Provean, SIFT, PolyPhen-2, MutationTaster, MutPred2, Align GVGD, SNAP, and PhD-SNP, consistently classified the variant as deleterious. Splicing predictions using Human Splicing Finder (HSF) and SpliceAI suggested disruption of regulatory motifs and activation of a cryptic splice site. To find potential structural consequences, molecular modeling of the wild-type and mutant RNA polymerase III complex (PDB: 7DN3) was performed using PyMOL, while DynaMut analysis revealed destabilizing effects, decreased residue flexibility, and steric clashes that could impair complex function. By integrating genetic, computational, and structural approaches, this study not only provides a comprehensive characterization of the POLR3A c.2707G > A (p.Gly903Arg) variant but also contributes to the expanding spectrum of genetic findings in WRS. Our findings highlight the importance of case reports in refining genotype-phenotype correlations and emphasize the need for further functional validation to elucidate the molecular mechanisms underlying WRS.

Progeroid syndromes are rare genetic disorders that impact patients' health and lifespans and are characterized by symptoms that mimic the normal aging process. Telomere length is one of the aging hallmarks, a phenomenon linked to cellular aging. Telomere attrition was observed in different progeroid syndromes, such as Nijmegen breakage syndrome patients and Werner syndrome, indicating its contribution to the progeroid phenotype. However, whether it is a common feature in all progeroid syndromes is still unclear. Therefore, in this study, we aimed to estimate telomere length using the DNA methylation-based estimator of human telomere length in publicly available DNA methylation data from patients with Werner Syndrome, Hutchinson-Gilford Progeria Syndrome, Berardinelli-Seip Congenital Lipodystrophy type 2, and Dyskeratosis congenita, along with additional data provided by our laboratory from patients with Cerebroretinal Microangiopathy with Calcifications and Cysts and Wiedemann-Rautenstrauch Syndrome. Our findings revealed that certain progeroid syndromes, including classical Werner Syndrome, Berardinelli-Seip Congenital Lipodystrophy type 2, and Dyskeratosis congenita, have significant telomere attrition conversely to Hutchinson-Gilford Progeria Syndrome, Cerebroretinal Microangiopathy with Calcifications and Cysts, Wiedemann-Rautenstrauch Syndrome, and atypical Werner Syndrome. In conclusion, this study addresses a critical gap by providing new insights into the role of telomere attrition across different progeroid conditions. Further research is needed to elucidate the effect of telomere attrition on progeroid syndromes and its implications.

The corpus callosum is one of the five main cerebral commissures. It is key to combining sensory and motor functions. Its structure can be pathological (dysgenesis) or completely absent (agenesis). The corpus callosum dys- or agenesis is a rare disease (1:4000 live births), but it can have serious mental effects. In our study, we processed the data of 64 pregnant women. They attended a prenatal diagnostic center and genetic counseling from 2005 to 2019 at the Department of Obstetrics and Gynecology at Semmelweis University. The pregnancies had the following outcomes: 52 ended in delivery, 1 in spontaneous abortion, and 11 in termination of pregnancy (TOP) cases (n = 64). The average time of detection with imaging tests was 25.24 gestational weeks. In 16 cases, prenatal magnetic resonance imaging (MRI) was performed. If the abnormality was detected before the 20th week, a genetic test was performed on an amniotic fluid sample obtained from a genetic amniocentesis. Karyotyping and cytogenetic tests were performed in 15 of the investigated cases. Karyotyping gave normal results in three cases (46,XX or XY). In one of these cases, postnatally chromosomal microarray (CMA) was later performed, which confirmed Aicardi syndrome (3q21.3-21.1 microdeletion). In one case, postnatally, the test found Wiedemann-Rautenstrauch syndrome. In other cases, it found X ring, Di George syndrome, 46,XY,del(13q)(q13q22) and 46,XX,del(5p)(p13) (Cri-du-chat syndrome). Edwards syndrome was diagnosed in six cases, and Patau syndrome in one case. We found that corpus callosum abnormalities are often linked to chromosomal problems. We recommend that a cytogenetic test be performed in all cases to rule out inherited diseases. Also, the long-term outcome does not just depend on the disease's severity and the associated other conditions, and hence proper follow-up and early development are also key. For this reason, close teamwork between neonatology, developmental neurology, and pediatric surgery is vital.