Case of a 33-Year-Old Woman With Hemoptysis and Migrant Nodular Cavitary Lesions.

We describe the case of a young 33-year-old woman that was referred to our clinic for evidence of migrant cavitary nodules at CT scan, dyspnea, and blood sputum. Her physical examination showed translucent and thin skin, evident venous vascular pattern, vermilion of the lip thin, micrognathia, thin nose, and occasional Raynaud phenomenon. We prescribed another CT scan that showed multiple pulmonary nodules in both lungs, some of which had evidence of cavitation. Because bronchoscopy was not diagnostic, we decided to perform surgical lung biopsy. At histologic examination, we found the presence of irregularly shaped, but mainly not dendritic, foci of ossification that often contained bone marrow and were embedded or surrounded by tendinous-like fibrous tissue. After incorporating data from the histologic examination, we decided to perform genetic counseling and genetic testing with the use of whole-exome sequencing. The genetic test revealed a heterozygous de novo missense mutation of COL3A1 gene, which encodes for type III collagen synthesis, and could cause vascular Ehlers-Danlos syndrome.

Cardiac Left Ventricular miRNA-26a Is Downregulated in Ovariectomized Mice, Upregulated upon 17-Beta Estradiol Replacement, and Inversely Correlated with Collagen Type 1 Gene Expression.

Heart failure with preserved ejection fraction (HFpEF) is more prevalent in post- compared to pre-menopausal women. The underlying mechanisms are not fully understood. Data in humans is confounded by age and co-morbidities. We investigated the effects of ovariectomy and estrogen replacement on the left ventricular (LV) gene expression of pro-inflammatory and pro-fibrotic factors involved in HFpEF and putative regulating miRNAs. Nine-week-old C57BL/6 female mice were subjected to ovariectomy (OVX) or SHAM operation. OVX and SHAM groups were sacrificed 1-, 6-, and 12-weeks post-surgery (T1/SHAM; T1/OVX; T6/SHAM; T6/OVX, T12/SHAM). 17ß-estradiol (E2) or vehicle (VEH) was then administered to the OVX groups for 6 weeks (T12/OVX/E2; T12/OVX/VEH). Another SHAM group was sacrificed 12-weeks post-surgery. RNA and miRNAs were extracted from the LV apex. An early 3-fold increase in the gene expression of IL-1α, IL-6, Mmp9, Mmp12, Col1α1, and Col3α1 was observed one-week post-surgery in T1/OVX vs. T1/SHAM, but not at later time points. miRNA-26a was lower in T1/OVX vs. T1/SHAM and was inversely correlated with Col1α1 and Col3α1 expression 1-week post-surgery (r = -0.79 p < 0.001; r = -0.6 p = 0.007). miRNAs-26a, 29b, and 133a were significantly higher, while Col1α1, Col3α1, IL-1α, IL-6, Tnfα, Mmp12, and FasL gene expression was significantly lower in E2- compared to vehicle-treated OVX mice. miRNA-26a was inversely correlated with Col3α1 in T12/OVX/ E2 (r = -0.56 p = 0.02). OVX triggered an early increase in the gene expression of pro-inflammatory and pro-fibrotic factors, highlighting the importance of the early phase post-cessation of ovarian function. E2 replacement therapy, even if it was not immediately initiated after OVX, reversed these unfavorable changes and upregulated cardiac miRNA-26a, previously unknown to be affected by menopausal status.

Effect of Vaginal Microecological Alterations on Female Pelvic Organ Prolapse.

INTRODUCTION AND HYPOTHESIS: The objective was to investigate the correlation between endogenous vaginal microecological alterations and female pelvic organ prolapse (POP). METHODS: Patients who underwent vaginal hysterectomy were retrospectively analyzed as the POP group (n = 30) and the non-POP group (n = 30). The vaginal microbial metabolites and enzyme levels were tested using the dry chemoenzymatic method. The mRNA and protein expression were tested using real-time quantitative PCR and immunohistochemistry. SPSS version 25.0 and GraphPad Prism 8.0 were performed for statistical analysis. RESULTS: Compared with the non-POP group, the vaginal pH, H2O2 positivity and leukocyte esterase positivity were higher in patients with POP (all p < 0.05). Further analysis showed that patients with pelvic organ prolapse quantification (POP-Q) stage IV had higher rates of vaginal pH, H2O2 positivity and leukocyte esterase positivity than those with POP-Q stage III. Additionally, the mRNA expression of decorin (DCN), transforming growth factor beta 1 (TGF-ß1), and matrix metalloproteinase-3 (MMP-3) in uterosacral ligament tissues were higher, whereas collagen I and III were lower. Similarly, the positive expression of MMP-3 in uterosacral ligament tissue was significantly upregulated in the POP group compared with the non-POP group (p = 0.035), whereas collagen I (p = 0.004) and collagen III (p = 0.019) in uterosacral ligament tissue were significantly downregulated in the POP group. Correlation analysis revealed that there was a significant correlation between vaginal microecology and collagen metabolism. In addition, MMP-3 correlated negatively with collagen I and collagen III (p = 0.002, r = -0.533; p = 0.002, r = -0.534 respectively), whereas collagen I correlated positively with collagen III (p = 0.001, r = 0.578). CONCLUSIONS: Vaginal microecological dysbiosis affects the occurrence of female POP, which could be considered a novel therapeutic option.

Preparation and characterization of a novel humanized collagen III with repeated fragments of Gly300-Asp329.

Recombinant human collagens have attracted intensive interest in the past two decades, demonstrating considerable potential in medicine, tissue engineering, and cosmetics. Several humanized recombinant collagens have been produced, exhibiting similar characteristics as the native species. To get insight into the structural and bioactive properties of different parts of collagen, in this study, the segment of Gly300-Asp329 of type III collagen was first adopted and repeated 18 times to prepare a novel recombinant collagen (named rhCLA). RhCLA was successfully expressed in E. coli, and a convenient separation procedure was established through reasonably combining alkaline precipitation and acid precipitation, yielding crude rhCLA with a purity exceeding 90%. Additionally, a polishing purification step utilizing cation exchange chromatography was developed, achieving rhCLA purity surpassing 98% and an overall recovery of approximately 120 mg/L culture. Simultaneously, the contents of endotoxin, nucleic acids, and host proteins were reduced to extremely low levels. This fragmented type III collagen displayed a triple-helical structure and gel-forming capability at low temperatures. Distinct fibrous morphology was also observed through TEM analysis. In cell experiments, rhCLA exhibited excellent biocompatibility and cell adhesion properties. These results provide valuable insights for functional studies of type III collagen and a reference approach for the large-scale production of recombinant collagens.

Generation of the human induced pluripotent stem cell line (IBKMOLi003-A) from PBMCs of a vascular Ehlers-Danlos syndrome (vEDS) patient carrying the heterozygous nonsense mutation c.430C > T (p.Q105*) in the COL3A1 gene.

Ehlers-Danlos syndrome (EDS) belongs to a spectrum of rare heritable connective tissue disorders and is characterised by hyperextensibility, joint hypermobility and tissue fragility. Peripheral blood mononuclear cells (PBMCs) from a vascular EDS (vEDS) patient, known as the rarest EDS subtype, carrying a heterozygous nonsense mutation c.430C > T (p.Q105*) in the COL3A1 gene, which is essential for type III collagen synthesis, were reprogrammed into induced pluripotent stem cells (iPSCs). The generated iPSCs exhibit high expression of pluripotency-associated markers, possess trilineage differentiation capacity and reveal a normal karyotype. This novel patient-specific cell line enables in-depth pathophysiological studies of vEDS.

RNF185 Control of COL3A1 Expression Limits Prostate Cancer Migration and Metastatic Potential.

RNF185 is a RING finger domain-containing ubiquitin ligase implicated in ER-associated degradation. Prostate tumor patient data analysis revealed a negative correlation between RNF185 expression and prostate cancer progression and metastasis. Likewise, several prostate cancer cell lines exhibited greater migration and invasion capabilities in culture upon RNF185 depletion. Subcutaneous inoculation of mouse prostate cancer MPC3 cells stably expressing short hairpin RNA against RNF185 into mice resulted in larger tumors and more frequent lung metastases. RNA-sequencing and Ingenuity Pathway Analysis identified wound-healing and cellular movement among the most significant pathways upregulated in RNF185-depleted lines, compared with control prostate cancer cells. Gene Set Enrichment Analyses performed in samples from patients harboring low RNF185 expression and in RNF185-depleted lines confirmed the deregulation of genes implicated in epithelial-to-mesenchymal transition. Among those, COL3A1 was identified as the primary mediator of RNF185's ability to impact migration phenotypes. Correspondingly, enhanced migration and metastasis of RNF185 knockdown (KD) prostate cancer cells were attenuated upon co-inhibition of COL3A1. Our results identify RNF185 as a gatekeeper of prostate cancer metastasis, partly via its control of COL3A1 availability. IMPLICATIONS: RNF185 is identified as an important regulator of prostate cancer migration and metastasis, in part due to its regulation of COL3A1. Both RNF185 and COL3A1 may serve as novel markers for prostate tumors.

Bioinformatic Analysis of the Mechanism of Action of COL3A1 in Pan-Cancer and Design of Specific Inhibitors for Its Conformation.

In this study, we investigated the mechanism of action of COL3A1 in various types of cancers by bioinformatics analysis and designed some specific inhibitors aimed at the treatment of this gene. We found that COL3A1 was highly expressed in several cancer types and correlated with tumor progression and prognosis. Through systems biology analysis, we identified a central role for COL3A1 in cancer development, including cell proliferation, metastasis and invasion. We also used molecular dynamics simulations and drug screening techniques to design anticancer drugs with potential COL3A1 inhibitory functions. These results provide a strong rationale for the development and use of COL3A1 as a therapeutic target.

Vascular Ehlers-Danlos syndrome with a Novel missense COL3A1 gene mutation present with bilateral spontaneous carotid-cavernous fistula: a case report.

This report describes a unique case of vascular Ehlers-Danlos syndrome (vEDS) characterized by multiple spontaneous direct carotid-cavernous sinus fistulas (CCF). The patient initially presented with ocular symptoms and was effectively treated with transarterial coil embolization. Five years later, the patient developed recurrent contralateral CCF that required complex endovascular techniques. Genetic testing identified a novel mutation in the COL3A1 gene, confirming the diagnosis of vEDS. This case report provides a near-term perspective on the identification of structural abnormalities in the COL3A1 protein to ensure the safety of endovascular therapy for patients with vEDS.

The selected genes NR6A1, RSAD2-CMPK2, and COL3A1 contribute to body size variation in Meishan pigs through different patterns.

The high-fertility Meishan pig is currently categorized into medium sized (MMS) and small sized (SMS) based on body size. To identify causal genes responsible for the variation in body size within the two categories, we sequenced individuals representing the entire consanguinity of the existing Meishan pig. This enabled us to conduct genome selective signal analysis. Our findings revealed the genomes of MMS and SMS are stratified, with selective sweep regions formed by differential genomic intervals between the two categories enriched in multiple pig body size related quantitative trait loci (QTLs). Furthermore, the missense mutation c.575T > C of candidate causal gene NR6A1, accounting for the variation in lumbar vertebrae number in pigs, was positively selected in MMS only, leading to an increase in body length of MMS at 6 months of age. To precisely identify causal genes accounting for body size variation through multi-omics, we collected femoral cartilage and liver transcription data from MMS and SMS respectively, and re-sequencing data from pig breeds exhibiting varying body sizes. We found that two selected regions where the RSAD2-CMPK2 and COL3A1 genes are located, respectively, showed different haplotypes in pig breeds of varying body size, and was associated with body or carcass length in hybridized Suhuai pig. Additionally, the above three hub genes, were significantly greater expressed in SMS femoral cartilage and liver tissues compared to MMS. These three genes could strengthen the pathways related to bone resorption and metabolism in SMS, potentially hindering bone and skeletal development and resulting in a smaller body size in SMS. These findings provide valuable insights into the genetic mechanism of body size variation in Meishan pig population.

The existing well-known Meishan pig population has been categorized into medium sized (MMS), and small sized (SMS) based on body size, which is a result of artificial selection. MMS is relatively large in all body size traits, but otherwise have highly similar appearance and performance traits. To effectively identify the candidate selected genes that contribute to the body size variation in Meishan pigs, this study collected individuals from all lineages of MMS and SMS for re-sequencing. Additionally, femoral cartilage and liver transcription data were collected from MMS and SMS, respectively, and re-sequencing data from pig breeds exhibiting varying body sizes were also analyzed. Through multi-omics analysis, it was discovered that the missense mutation c.575T > C in the candidate causal gene NR6A1 was positively selected in MMS only, leading to an increase in the body length of MMS at 6 months of age. Moreover, the selected genes RSAD2-CMPK2 and COL3A1 were found to be significantly greater expressed in SMS femoral cartilage and liver tissues compared with MMS. These genes could potentially strengthen bone resorption and metabolism-related pathways in SMS. These findings contribute to a better understanding of the genetic mechanisms underlying body size variation in Meishan pigs and Chinese indigenous pigs.

Identification of two novel COL3A1 variants in patients with vascular Ehlers-Danlos syndrome.

BACKGROUND: Vascular Ehlers-Danlos syndrome (vEDS) is an autosomal dominant disease caused by aberrations in COL3A1, which encodes type III collagen. Sanger sequencing has limitations for diagnosis since exon deletion/duplication and splicing alterations are not uncommon in COL3A1. We report 2 patients with vEDS who were not diagnosed by conventional Sanger sequencing. METHODS: We performed either targeted panel or whole-genome sequencing. Complementary DNA (cDNA) sequencing was performed using cultured skin fibroblasts. Sanger sequencing of DNA was performed for the confirmation of breakpoints in the case of exon deletion. We also evaluated the sensitivity of the splicing prediction tool, SpliceAI. RESULTS: An exon 27 deletion was suspected on targeted panel sequencing of 1 patient. The deletion was confirmed using cDNA sequencing (r.1870_1923del) and breakpoints were confirmed (c.1870-109_1923+10del). On targeted panel sequencing in the other patient, we found a novel intronic variant of c.1149+6T>C that leads to skipping of exon 16 (r.1051_1149del) by cDNA sequencing. SpliceAI showed 98.8% sensitivity for known splicing variants in COL3A1. CONCLUSION: Our study highlights the necessity of a comprehensive approach to the genetic diagnosis of vEDS. In addition, cDNA sequencing was useful as an auxiliary method, especially considering the limited sensitivity of the splicing prediction tool.

Effect and mechanism of signal peptide and maltose on recombinant type III collagen production in Pichia pastoris.

Recombinant type III collagen plays an important role in cosmetics, wound healing, and tissue engineering. Thus, increasing its production is necessary. After an initial increase in output by modifying the signal peptide, we showed that adding 1% maltose directly to the medium increased the yield and reduced the degradation of recombinant type III collagen. We initially verified that Pichia pastoris GS115 can metabolize and utilize maltose. Interestingly, maltose metabolism-associated proteins in Pichia pastoris GS115 have not yet been identified. RNA sequencing and transmission electron microscopy were performed to clarify the specific mechanism of maltose influence. The results showed that maltose significantly improved the metabolism of methanol, thiamine, riboflavin, arginine, and proline. After adding maltose, the cell microstructures tended more toward the normal. Adding maltose also contributed to yeast homeostasis and methanol tolerance. Finally, adding maltose resulted in the downregulation of aspartic protease YPS1 and a decrease in yeast mortality, thereby slowing down recombinant type III collagen degradation. KEY POINTS: • Co-feeding of maltose improves recombinant type III collagen production. • Maltose incorporation enhances methanol metabolism and antioxidant capacity. • Maltose addition contributes to Pichia pastoris GS115 homeostasis.

Patient-derived extracellular matrix demonstrates role of COL3A1 in blood vessel mechanics.

Vascular Ehlers-Danlos Syndrome (vEDS) is a rare autosomal dominant disease caused by mutations in the COL3A1 gene, which renders patients susceptible to aneurysm and arterial dissection and rupture. To determine the role of COL3A1 variants in the biochemical and biophysical properties of human arterial ECM, we developed a method for synthesizing ECM directly from vEDS donor fibroblasts. We found that the protein content of the ECM generated from vEDS donor fibroblasts differed significantly from ECM from healthy donors, including upregulation of collagen subtypes and other proteins related to ECM structural integrity. We further found that ECM generated from a donor with a glycine substitution mutation was characterized by increased glycosaminoglycan content and unique viscoelastic mechanical properties, including increased time constant for stress relaxation, resulting in a decrease in migratory speed of human aortic endothelial cells when seeded on the ECM. Collectively, these results demonstrate that vEDS patient-derived fibroblasts harboring COL3A1 mutations synthesize ECM that differs in composition, structure, and mechanical properties from healthy donors. These results further suggest that ECM mechanical properties could serve as a prognostic indicator for patients with vEDS, and the insights provided by the approach demonstrate the broader utility of cell-derived ECM in disease modeling. STATEMENT OF SIGNIFICANCE: The role of collagen III ECM mechanics remains unclear, despite reported roles in diseases including fibrosis and cancer. Here, we generate fibrous, collagen-rich ECM from primary donor cells from patients with vascular Ehlers-Danlos syndrome (vEDS), a disease caused by mutations in the gene that encodes collagen III. We observe that ECM grown from vEDS patients is characterized by unique mechanical signatures, including altered viscoelastic properties. By quantifying the structural, biochemical, and mechanical properties of patient-derived ECM, we identify potential drug targets for vEDS, while defining a role for collagen III in ECM mechanics more broadly. Furthermore, the structure/function relationships of collagen III in ECM assembly and mechanics will inform the design of substrates for tissue engineering and regenerative medicine.

Splenic artery pathology presentation, operative interventions, and outcomes in 88 patients with vascular Ehlers-Danlos syndrome.

OBJECTIVE: Vascular Ehlers-Danlos syndrome (VEDS) is rare and associated with arteriopathies. The aim of this study is to investigate the presentation, operative interventions, and outcomes of splenic arterial pathology in a population of more than 1500 individuals with genetically confirmed VEDS due to pathogenic COL3A1 variants. METHODS: Cross-sectional analysis of 1547 individuals was performed. The data were assembled by harmonizing data from three overlapping cohorts with genetically confirmed VEDS: the VEDS Collaborative Natural History Study (N = 242), a single-center cohort (N = 75), and the University of Washington Collagen Diagnostic Lab cohort (N = 1231). Duplicates were identified and removed. Patients were selected for analysis if they had splenic artery aneurysm (SAA), pseudoaneurysm, dissection, thrombosis, or rupture. Demographics, COL3A1 variants, interventions, and outcomes were analyzed. Comparisons by splenic artery rupture were made. RESULTS: A total of 88 patients presented between 1992 and 2021 with splenic artery pathology (5.7% of the cohort; mean age at diagnosis, 37 ± 11.1 years; 50% male). One-third were diagnosed with VEDS prior to the splenic artery pathology diagnosis, and 17% were diagnosed post-mortem. Most had a positive family history (61%). Most had COL3A1 variants associated with minimal normal collagen production (71.6%). Median follow up was 8.5 years (interquartile range, 0.9-14.7 years). Initial presentation was rupture in 47% of the cases. Splenic artery rupture overall was 51% (n = 45), including four cases of splenic rupture. There were no major differences in VEDS-related manifestations or COL3A1 variant type by rupture status. SAA was noted in 39% of the cases. Only 12 patients had splenic artery diameter documented in 12 cases with a median diameter of 12 mm (interquartile range, 10.3-19.3 mm). A total of 34 patients (38.6%) underwent 40 splenic arterial interventions: 21 open surgical, 18 embolization, and one unknown procedure. More than one splenic artery intervention was performed in five cases (14.7%). Open repair complications included arteriovenous fistula (n = 1), intestinal or pancreatic injury (n = 1 each), and four intraoperative deaths. There were no deaths or access site complications related to splenic artery embolization. Four patients (23.5%) developed a new SAA in the remaining splenic artery post embolization. All-cause mortality was 35% (n = 31), including 22 related to a ruptured splenic artery. CONCLUSIONS: Splenic arteriopathy in VEDS is associated with variants that affect the structure and secretion of type III collagen and frequently present with rupture. Rupture and open repair are associated with high morbidity and mortality, whereas embolization is associated with favorable outcomes. Suggest repair considerations at SAA diameter of 15 mm. Long-term follow-up is indicated as secondary splenic arteriopathy can occur.

Diagnosis and management of vascular Ehlers-Danlos syndrome: Experience of the UK national diagnostic service, Sheffield.

The UK National Diagnostic Service for Ehlers-Danlos Syndromes (EDS) was established in 2009 for the rare types of EDS. Vascular EDS (vEDS) is an inherited connective tissue disorder caused by pathogenic variants in the COL3A1 gene. Associated tissue fragility affects multiple organ systems, increasing the risk of blood vessel dissection and rupture, with potentially fatal consequences. The diagnosis of vEDS has improved with advances in genetic testing, however this is most often suspected following an acute event. We provide data on the clinical features of vEDS for 180 patients (full cohort) seen in our service with confirmed molecular diagnoses. Increased awareness of this rare condition will prompt genetic testing essential to confirm the diagnosis. Outcomes are improved by early diagnosis followed by appropriate management. Fragile connective tissues make invasive procedures potentially dangerous, particularly in an emergency setting. Lifestyle advice from a young age can help acceptance and understanding of the diagnosis and inform choices. There is currently limited evidence for the use of drug therapy to reduce vascular events. We report on the incidence of vascular events in 126 patients (statistical analysis cohort) in our care and the use of medication. Our retrospective data showed that those patients on a long-term angiotensin II receptor blocker and/or beta-blocker had fewer vascular events than those not on cardiac medication who received the same lifestyle and emergency care advice.

The first case of lipoprotein glomerulopathy complicated with collagen type III glomerulopathy and literature review.

Lipoprotein glomerulopathy (LPG) is a rare autosomal dominant kidney disease caused by pathogenic mutations in the APOE gene. Collagen type III glomerulopathy (CG) is a sporadic condition in adults characterized by abnormal accumulation of type III collagen in the subendothelial space and mesangium of the glomerulus. We report the first case of both LPG and CG in a 21-year-old male. A search of the literature found no confirmed reports of these two concomitant nephropathies. The patient presented with hypertension, proteinuria, hematuria and hyperlipidemia. Renal pathology showed lipid vacuoles in the enlarged glomerular capillary loops and type III collagen in the segmental mesangial area and on the inner side of the glomerular basement membrane by electron microscopy. Whole-exome sequencing revealed a heterozygous mutation (c.127C>T; p. Arg43Cys) in exon 3 of the APOE gene, known as the APOE-Kyoto of LPG. In addition, two heterozygous COL4A4 mutations (c.4715C>T in exon 47 and c.5065 T>C in exon 48) were observed, the first one was suspected pathogenic and the other one was uncertain significant. There is no special treatment for these diseases. The patient was treated with lipid-lowering agents, renin-angiotensin-aldosterone system inhibition and tripterygium glycosides. The patient received double-filtration plasmapheresis and immunoadsorption therapy when renal function deteriorated dramatically. Immunoadsorption was beneficial for this patient.

Co-expression of recombinant human collagen α1(III) chain with viral prolyl 4-hydroxylase in Pichia pastoris GS115.

The Collagen α1(Ш) chain (COL3A1) is an important structural protein on the surface of human skin. The activity of prolyl 4-hydroxylase (P4H) is crucial to maintaining the stable triple-helix structure and function of human COL3A1. To obtain hydroxylated human COL3A1, virus-derived P4H A085R was co-expressed with human COL3A1 in Pichia pastoris GS115. Colony PCR analysis and sequencing after transfection confirmed that the target gene was successfully inserted. Quantitative reverse transcription PCR (RT-qPCR) indicated that human COL3A1 and P4H A085R were expressed at mRNA levels in the clones. SDS-PAGE and Western blot analysis of supernatant from the recombinant methylotrophic yeast culture showed that recombinant human COL3A1 (rhCOL3A1) was secreted into the culture medium with an apparent molecular mass of approximately 130 kDa. It was observed that the amount of secreted rhCOL3A1 was highest at 120 h after induction. Furthermore, mass spectrometry analysis demonstrated that rhCOL3A1 was successfully expressed in P. pastoris. The His-tagged rhCOL3A1 protein was purified by Ni-affinity column chromatography.

Comprehensive genetic screening for vascular Ehlers-Danlos syndrome through an amplification-based next-generation sequencing system.

Vascular Ehlers-Danlos syndrome (vEDS) is a hereditary connective tissue disorder (HCTD) characterized by arterial dissection/aneurysm/rupture, sigmoid colon rupture, or uterine rupture. Diagnosis is confirmed by detecting heterozygous variants in COL3A1. This is the largest Asian case series and the first to apply an amplification-based next-generation sequencing through custom panels of causative genes for HCTDs, including a specific method of evaluating copy number variations. Among 429 patients with suspected HCTDs analyzed, 101 were suspected to have vEDS, and 33 of them (32.4%) were found to have COL3A1 variants. Two patients with a clinical diagnosis of Loeys-Dietz syndrome and/or familial thoracic aortic aneurysm and dissection were also found to have COL3A1 variants. Twenty cases (57.1%) had missense variants leading to glycine (Gly) substitutions in the triple helical domain, one (2.9%) had a missense variant leading to non-Gly substitution in this domain, eight (22.9%) had splice site alterations, three (8.6%) had nonsense variants, two (5.7%) had in-frame deletions, and one (2.9%) had a multi-exon deletion, including two deceased patients analyzed with formalin-fixed and paraffin-embedded samples. This is a clinically useful system to detect a wide spectrum of variants from various types of samples.