Time gap between the onset and diagnosis in Werner syndrome: a nationwide survey and the 2020 registry in Japan

The identification of a novel mutation (p.I223fs) in WRN associated with Werner syndrome

PURPOSE

Werner syndrome (WS) is a rare autosomal recessive genetic disease caused by mutations in the WRN gene, and it is characterized by multiple manifestations corresponding to early-onset aging. This study reports the case of a WS patient with a novel WRN mutation.

PATIENT AND METHODS

A 36-year-old male patient with WS was evaluated after approval from the local ethics committee. The clinical and biochemical findings of the patient were described. Peripheral blood sample was collected to extract genomic DNA for WRN gene exome sequencing. The three-dimensional (3D) protein structural prediction analysis was performed via the AlphaFold 2.2 program and PyMol software.

RESULTS

We report the case of a clinically diagnosed WS patient with consanguineous parents who presented with complex manifestations including early-onset diabetes mellitus, binocular cataracts, cerebral infarction, cerebral atherosclerosis, hypertension, dyslipidemia, hypothyroidism, and suspected meningioma, accompanied by short stature, gray hair, rough skin with subcutaneous fat atrophy, a high-pitched voice, palmoplantar keratoderma, bilateral flat feet, and an indolent deep ulceration on the foot. Exome sequencing identified a novel homozygous frameshift mutation in the WRN gene, c.666-669 del TATT, p.I223fs. The 3D structure prediction showed that premature termination and significant structural changes could occur in the mutant WRN protein.

CONCLUSION

We identified a novel homozygous frameshift mutation, p.I223fs, in WRN in a Chinese patient with WS, expanding the spectrum of mutations in WS.

Sex differences in symptom presentation and their impact on diagnostic accuracy in Werner syndrome

AIM

Whether sex differences exist in hereditary progeroid syndromes remains unclear. In this study, we investigated sex differences in patients with Werner syndrome (WS), a model of human aging, using patient data at the time of diagnosis.

METHODS

The presence of six cardinal signs in the diagnostic criteria was retrospectively evaluated.

RESULTS

We found that the percentage of patients with all cardinal signs was higher in males than in females (54.2% vs. 21.2%). By the age of 40 years, 57.1% of male patients with WS presented with all the cardinal signs, whereas none of the female patients developed all of them. In particular, the frequency of having a high-pitched, hoarse voice, a characteristic of WS, was lower in female patients. The positive and negative predictive values for clinical diagnosis were 100% for males and females, indicating the helpfulness of diagnostic criteria regardless of sex. More female patients than male (86.7% vs. 64%) required genetic testing for their diagnosis because their clinical symptoms were insufficient, suggesting the importance of genetic testing for females even if they do not show typical symptoms of WS. Finally, the frequency of abnormal voice was lower in patients with WS harboring the c.3139-1G > C homozygous mutation.

CONCLUSION

These results indicate, for the first time, that there are sex differences in the phenotypes of hereditary progeroid syndromes. The analysis of this mechanism in this human model of aging may lead to the elucidation of sex differences in the various symptoms of normal human aging. Geriatr Gerontol Int 2024; 24: 161-167.

Senescence-associated inflammation and inhibition of adipogenesis in subcutaneous fat in Werner syndrome

Werner syndrome (WS) is a hereditary premature aging disorder characterized by visceral fat accumulation and subcutaneous lipoatrophy, resulting in severe insulin resistance. However, its underlying mechanism remains unclear. In this study, we show that senescence-associated inflammation and suppressed adipogenesis play a role in subcutaneous adipose tissue reduction and dysfunction in WS. Clinical data from four Japanese patients with WS revealed significant associations between the decrease of areas of subcutaneous fat and increased insulin resistance measured by the glucose clamp. Adipose-derived stem cells from the stromal vascular fraction derived from WS subcutaneous adipose tissues (WSVF) showed early replicative senescence and a significant increase in the expression of senescence-associated secretory phenotype (SASP) markers. Additionally, adipogenesis and insulin signaling were suppressed in WSVF, and the expression of adipogenesis suppressor genes and SASP-related genes was increased. Rapamycin, an inhibitor of the mammalian target of rapamycin (mTOR), alleviated premature cellular senescence, rescued the decrease in insulin signaling, and extended the lifespan of WS model of C. elegans. To the best of our knowledge, this study is the first to reveal the critical role of cellular senescence in subcutaneous lipoatrophy and severe insulin resistance in WS, highlighting the therapeutic potential of rapamycin for this disease.

Renal dysfunction, malignant neoplasms, atherosclerotic cardiovascular diseases, and sarcopenia as key outcomes observed in a three-year follow-up study using the Werner Syndrome Registry

Werner syndrome is an adult-onset progeria syndrome that results in various complications. This study aimed to clarify the profile and secular variation of the disease. Fifty-one patients were enrolled and registered in the Werner Syndrome Registry. Their data were collected annually following registration. A cross-sectional analysis at registration and a longitudinal analysis between the baseline and each subsequent year was performed. Pearson's chi-squared and Wilcoxon signed-rank tests were used. Malignant neoplasms were observed from the fifth decade of life (mean onset: 49.7 years) and were observed in approximately 30% of patients during the 3-year survey period. Regarding renal function, the mean estimated glomerular filtration rate calculated from serum creatinine (eGFRcre) and eGFRcys, which were calculated from cystatin C in the first year, were 98.3 and 83.2 mL/min/1.73 m2, respectively, and differed depending on the index used. In longitudinal analysis, the average eGFRcre for the first and fourth years was 74.8 and 63.4 mL/min/1.73 m2, showing a rapid decline. Secular changes in Werner syndrome in multiple patients were identified. The prevalence of malignant neoplasms is high, and renal function may decline rapidly. It is, therefore, necessary to carry out active and detailed examinations and pay attention to the type and dose of the drugs used.

Quality of life in Werner syndrome and associated subjective foot/ankle symptoms: A cross-sectional survey

AIM

The aims of this study were to assess the general quality of life and foot/ankle health-related quality of life among subjects with Werner syndrome (WS) and to determine subjective foot/ankle symptoms associated with quality of life.

METHODS

Using a questionnaire survey, patients were asked to provide information on age, sex and presence of subjective symptoms and complete both the 36-Item Short Form Health Survey (SF-36) questionnaire and the Self-Administered Foot Evaluation Questionnaire (SAFE-Q). Statistical analyses were performed using Student's t-test, the Mann-Whitney U test, Fisher's exact test and Spearman's rank correlation.

RESULTS

Data from 12 patients with an average age of 54 ± 8.6 years were analyzed. The mean SF-36 score for the domain of physical functioning was 21.2; for role-physical function, 32.6; for bodily pain, 38.5; for general health, 34.4; for vitality, 44.8; for social function, 38.5; for role-emotional function and for mental health, 46.7. The mean mental component summary was as high as the national standard, but it was low in men. The mean SAFE-Q scores were also low. Patients with ulcers had significantly more pain and low general health perception. As compared with the national standard, the role/social component score was not low, and there was a correlation in most domains of the SAFE-Q.

CONCLUSION

In WS, the general health-related quality of life was low overall in the physical domain and low only in men for the mental domain, whereas it was low in the social domain when foot/ankle health-related quality of life was low. Geriatr Gerontol Int 2023; 23: 188-193.

Optical coherence tomography findings in three patients with Werner syndrome

Background

Werner syndrome is a rare, autosomal recessive disorder characterised by premature aging. It is a typical hereditary progeroid syndrome that can be difficult to diagnose owing to its rarity and the similarity of some of its symptoms, such as juvenile cataracts, to other common ophthalmologic conditions. Early onset of bilateral cataracts is currently used as the ophthalmological feature for Werner syndrome; however, ophthalmologists often find performing a detailed examination of the medical history and genetic testing for Werner syndrome at the time of an ophthalmologic consultation challenging. If a unique ocular finding was observed on ocular examinations in cases of juvenile bilateral cataracts, we could consider Werner syndrome as a differential diagnosis. 

Case presentation

We documented the cases of three patients with Werner syndrome in whom thinning of the retina in the retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) were observed using optical coherence tomography (OCT). Visual field tests revealed the loss of visual field mainly owing to glaucoma.

The thinnig of the choroidal thickness (CT) in three patients was also observed using enhanced depth imaging (EDI)-OCT.

Conclusions

Three patients have thinning of the RNFL, GCC, and choroidal thickness and the loss of visual field. These findings suggest the need for including Werner syndrome in the differential diagnosis when patients presenting with juvenile cataracts of unknown cause also show abnormal retinal and choroidal thinning in the OCT images.

Lifetime extension and the recent cause of death in Werner syndrome: a retrospective study from 2011 to 2020

Background

Werner syndrome (WS) is an autosomal recessive premature ageing disease that causes accelerated ageing-like symptoms after puberty. Previous studies conducted in the late 2000s reported that malignant neoplasms and atherosclerotic diseases were the two leading causes of death, with life expectancies in the mid-50 s. However, the recent lifespan and cause of death in patients with WS remain unclear.

Objective

To clarify the latest lifespan and causes of death in patients with WS.

Method

We conducted a questionnaire-based survey in 2020 among the primary doctors of WS patients who were identified in previous nationwide surveys in Japan and clarified the following: the age of WS patients (age of death, if the patient had already died), sex, and cause of death. Patients who died in 2010 or earlier were excluded from the analysis.

Results

A total of 123 living patients were identified at the time of the survey in 2020. Fourteen WS patients died between 2011 and 2020, with a mean age of 59.0 ± 8.9 years (mean ± SD). The most common cause of death was non-epithelial tumours, accounting for eight deaths, while no patient died of atherosclerotic diseases.

Conclusions

Compared to previous studies, this study suggests that the lifespan of patients with WS has been extended. Although there were no deaths due to atherosclerotic diseases, non-epithelial tumours were still the leading cause of death. Further development of screening and treatment methods for these tumours is required.

Targeted long-read sequencing identifies missing pathogenic variants in unsolved Werner syndrome cases

BACKGROUND

Werner syndrome (WS) is an autosomal recessive progeroid syndrome caused by variants in WRN. The International Registry of Werner Syndrome has identified biallelic pathogenic variants in 179/188 cases of classical WS. In the remaining nine cases, only one heterozygous pathogenic variant has been identified.

METHODS

Targeted long-read sequencing (T-LRS) on an Oxford Nanopore platform was used to search for a second pathogenic variant in WRN. Previously, T-LRS was successfully used to identify missing variants and analyse complex rearrangements.

RESULTS

We identified a second pathogenic variant in eight of nine unsolved WS cases. In five cases, T-LRS identified intronic splice variants that were confirmed by either RT-PCR or exon trapping to affect splicing; in one case, T-LRS identified a 339 kbp deletion, and in two cases, pathogenic missense variants. Phasing of long reads predicted all newly identified variants were on a different haplotype than the previously known variant. Finally, in one case, RT-PCR previously identified skipping of exon 20; however, T-LRS did not detect a pathogenic DNA sequence variant.

CONCLUSION

T-LRS is an effective method for identifying missing pathogenic variants. Although limitations with computational prediction algorithms can hinder the interpretation of variants, T-LRS is particularly effective in identifying intronic variants.

Case Report: A novel WRN mutation in Werner syndrome patient with diabetic foot disease and myelodysplastic syndrome

Werner syndrome is an autosomal recessive rare disease caused by a WRN gene mutation, which is rarely reported in the Chinese population. We report the clinical and genetic data of a Chinese patient with Werner syndrome. The proband was a 40-year-old male patient who presented with diabetic foot ulcers, accompanied by short stature, cataracts, hypogonadism, and hair thinning, and myelodysplastic syndrome (MDS) occurred after 18 months. Genetic sequencing showed there were compound heterozygous mutations as c.3384-1G>C and c.3744dupA in the WRN gene. The c.3744dupA mutation is a novel pathogenic variation for Werner syndrome.

Examination of the body composition of patients with Werner syndrome using bioelectrical impedance analysis

AIM

This study performed anthropometric measurements for Werner syndrome (WS) using bioelectrical impedance analysis and compared them with the Japanese reference data.

METHODS

The analytical sample included nine participants with WS (four men, five women, 49.6 ± 9.3 years, SD). The height-corrected appendicular skeletal muscle mass index (SMI), upper- and lower-limb muscle mass index (USMI/LSMI) of the patients with WS were compared with the Japanese reference data (40-79 years). The body mass index, SMI, height-corrected fat mass index (FMI) and fat-free mass index (FFMI) were compared with the reference data of Japanese older adults (65-94 years). The SMIs of WS were also compared with the diagnostic criteria for sarcopenia.

RESULTS

The SMI and USMI/LSMI of all participants with WS were lower than the Japanese reference data corresponding to gender and age, and the rate of decrease was more pronounced for USMI than for LSMI. The body mass index, SMI and FFMI for all the WS cases were lower than those for the older Japanese, while the FMI was higher in men with WS but lower in women than the reference data of the older Japanese. The SMI was below the cut-off value for the diagnosis of sarcopenia in all patients with WS.

CONCLUSION

The SMI for WS is comparable with that for sarcopenia and significantly lower than that for healthy individuals of the same age and older adults. The USMI was significantly lower than LSMI in patients with WS, and FMI was higher in male patients with WS and lower in women than in healthy older people. Geriatr Gerontol Int ••; ••: ••-•• Geriatr Gerontol Int 2021; ••: ••-••.

Werner syndrome presenting as early-onset diabetes: A case report

Werner syndrome is a rare autosomal recessive premature progeroid syndrome caused by mutations in the WRN gene. It is characterized by early onset of age‐related diseases, such as cataracts, atherosclerosis, diabetes mellitus, osteoporosis and malignancies, in which diabetes often onset in patients’ 30–40s. Herein, we report a Chinese patient with Werner syndrome with uncommon early‐onset diabetes at 18 years‐of‐age, who had low body mass index, insulin resistance, negative antibodies of diabetes and early onset of cataracts. Genome sequencing and reverse transcription polymerase chain reaction confirm the diagnosis. A novel heterozygous splice‐site mutation in the WRN gene (c.1270‐2A>T) was identified. The present case reminds clinicians that when young diabetes patients are encountered, if they are accompanied by premature aging, attention should be paid to identifying the possibility of Werner syndrome based on diagnostic criteria.

Atherosclerosis and Cardiovascular Diseases in Progeroid Syndromes

Hutchinson–Gilford progeria syndrome (HGPS) and Werner syndrome (WS) are two of the representative genetic progeroid syndromes and have been widely studied in the field of aging research. HGPS is a pediatric disease in which premature aging symptoms appear in early childhood, and death occurs at an average age of 14.5 years, mainly due to cardiovascular disease (CVD). Conversely, WS patients exhibit accelerated aging phenotypes after puberty and die in their 50s due to CVD and malignant tumors. Both diseases are models of human aging, leading to a better understanding of the aging-associated development of CVD. In this review, we discuss the pathogenesis and treatment of atherosclerotic diseases presented by both progeroid syndromes with the latest findings.

Differences of Sleep Disorders Between Vestibular Migraine and Benign Paroxysmal Positional Vertigo

Introduction: Sleep disorders can affect the overall health and quality of life of patients. This study was conducted to compare the differences of sleep disorders in vestibular migraine (VM) patients and benign paroxysmal positional vertigo (BPPV) patients. Methods: VM patients, BPPV patients, and healthy controls (HCs) were recruited. Pittsburgh sleep quality index and polysomnography monitoring were used as subjective and objective, respectively, evaluation methods to evaluate the sleep quality of participants in the latest month. Results: Fifty-seven BPPV patients, 48 VM patients, and 42 HCs were included in this study. There were 79.16% VM patients, 54.39% BPPV patients, and 14.28% HCs with sleep disorders. The difference in the incidence rate of sleep disorders was significant between VM patients and BPPV patients (p = 0.008) and significantly higher in both the VM group (p < 0.00001) and BPPV group (p = 0.00004) than in the HC groups (14.28%). Compared with BPPV patients, the VM patients had the significantly lower sleep efficiency (p < 0.001) and N3 (p < 0.001) and the significantly higher time of wake-up after sleep onset (p < 0.001), N1 (p < 0.001), and N2 (p < 0.001). Meanwhile, the VM patients had significantly higher incidence rates of severe obstructive sleep apnea hypoventilation syndrome (p = 0.001) and periodic leg movement in sleep (p = 0.016). Conclusion: The incidence rate of sleep disorders was significantly higher in both VM and BPPV patients than in the HC groups. To improve the curative effects, clinicians should pay more attention to the comorbidity of sleep disorders in treating VM and BPPV.