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Werner syndrome is a rare autosomal recessive premature aging syndrome characterized by its development after puberty and death in patients in their 50s due to cancer or atherosclerotic disease. Early diagnosis can improve the management of disease, quality of life and prolong the lifespan of patients with Werner syndrome. Ophthalmologists should include Werner syndrome in the general work-up in patients with bilateral early-onset cataracts. We present a case of Werner syndrome with initial signs of juvenile cataracts. The patient had a high-pitched voice, a bird-like face and progeroid hair. We performed routine ophthalmological examinations including slit-lamp examinations, fundus examinations, and optical coherence tomography, and genetic analysis. The patient had plateau iris and pachychoroid-like features in addition to bilateral cataracts. The gene analysis revealed compound heterozygosity of Mut4 and Mut25 in WRN and the patient was diagnosed with Werner syndrome. After cataract surgeries, his visual acuities were improved. Additionally, we performed a thorough literature review to better understand the previously reported ocular manifestations in patients 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.

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. We report a Chinese patient with Werner syndrome with uncommon early‐onset diabetes at age 18 years, 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. The present case reminds clinicians that when young type 2 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.

Werner syndrome (WS) is an adult onset segmental progeroid syndrome caused by mutations in the WRN gene. The WRN gene encodes a 180 kDa nuclear protein that possesses helicase and exonuclease activities. The absence of WRN protein leads to abnormalities in various DNA metabolic pathways such as DNA repair, replication and telomere maintenance. Individuals with WS generally develop normally until the third decade of life, when premature aging phenotypes and a series of age-related disorders begin to manifest. In Japan, where a founder effect has been described, the frequency of Werner heterozygotes appears to be as high as 1/180 in the general population. Due to the relatively non-specific nature of the symptoms and the lack of awareness of the condition, this disease may be under-diagnosed in other parts of the world. Genetic counseling of WS patients follows the path of other autosomal recessive disorders, with special attention needed for cancer surveillance in relatives. Molecular diagnosis of WS is made by nucleotide sequencing and, in some cases, protein analysis. It is also of potential interest to measure WRN activities in WS patients. More than 50 different disease-causing mutations in the WRN gene have been identified in WS patients from all over the world. All but one of these cases has mutations that result in the premature termination of the protein. Here we describe the clinical, molecular and biochemical characteristics of WS for use by medical professionals in a health care setting. Additional information is available through the International Registry of WS ( http://www.wernersyndrome.org ).

The International Registry of Werner syndrome (www.wernersyndrome.org) has been providing molecular diagnosis of the Werner syndrome (WS) for the past decade. The present communication summarizes, from among 99 WS subjects, the spectrum of 50 distinct mutations discovered by our group and by others since the WRN gene (also called RECQL2 or REQ3) was first cloned in 1996; 25 of these have not previously been published. All WRN mutations reported thus far have resulted in the elimination of the nuclear localization signal at the C‐terminus of the protein, precluding functional interactions in the nucleus; thus, all could be classified as null mutations. We now report two new mutations in the N‐terminus that result in instability of the WRN protein. Clinical data confirm that the most penetrant phenotype is bilateral ocular cataracts. Other cardinal signs were seen in more than 95% of the cases. The median age of death, previously reported to be in the range of 46–48 years, is 54 years. Lymphoblastoid cell lines (LCLs) have been cryopreserved from the majority of our index cases, including material from nuclear pedigrees. These, as well as inducible and complemented hTERT (catalytic subunit of human telomerase) immortalized skin fibroblast cell lines are available to qualified investigators. Hum Mutat 27(6), 558–567, 2006. Published 2006 Wiley‐Liss, Inc.

Werner's syndrome is a progeroid syndrome caused by mutations at the WRN helicase locus. Some features of this disorder are also present in laminopathies caused by mutant LMNA encoding nuclear lamin A/C. Because of this similarity, we sequenced LMNA in individuals with atypical Werner's syndrome (wild-type WRN). Of 129 index patients referred to our international registry for molecular diagnosis of Werner's syndrome, 26 (20%) had wildtype WRN coding regions and were categorised as having atypical Werner's syndrome on the basis of molecular criteria. We sequenced all exons of LMNA in these individuals. Mutations were confirmed at the mRNA level by RT-PCR sequencing. In one patient in whom an LMNA mutation was detected and fibroblasts were available, we established nuclear morphology and subnuclear localisation. In four (15%) of 26 patients with atypical Werner's syndrome, we noted heterozygosity for novel missense mutations in LMNA, specifically A57P, R133L (in two people), and L140R. The mutations altered relatively conserved residues within lamin A/C. Fibroblasts from the patient with the L140R mutation had a substantially enhanced proportion of nuclei with altered morphology and mislocalised lamins. Individuals with atypical Werner's syndrome with mutations in LMNA had a more severe phenotype than did those with the disorder due to mutant WRN. Our findings indicate that Werner's syndrome is molecularly heterogeneous, and a subset of the disorder can be judged a laminopathy.

The RecQ helicases belong to the Superfamily II group of DNA helicases, and are defined by amino acid motifs that show sequence similarity to the catalytic domain of Escherichia coli RecQ. RecQ helicases have crucial roles in the maintenance of genome stability. In humans, there are five RecQ helicases and deficiencies in three of them cause genetic disorders characterised by cancer predisposition, premature aging and/or developmental abnormalities. RecQ helicase-deficient cells exhibit aberrant genetic recombination and/or DNA replication, which result in chromosomal instability and a decreased potential for proliferation. Here, we review the current knowledge of the molecular genetics of RecQ helicases, focusing on the human RecQ helicase disorders and mouse models of these conditions.

Background Laminopathies, due to mutations in LMNA , encoding A type-lamins, can lead to premature ageing and/or lipodystrophic syndromes, showing that these diseases could have close physiopathological relationships. We show here that lipodystrophy and extreme insulin resistance can also reveal the adult progeria Werner syndrome linked to mutations in WRN , encoding a RecQ DNA helicase. Methods We analysed the clinical and biological features of two women, aged 32 and 36, referred for partial lipodystrophic syndrome which led to the molecular diagnosis of Werner syndrome. Cultured skin fibroblasts from one patient were studied . Results Two normal-weighted women presented with a partial lipodystrophic syndrome with hypertriglyceridemia and liver steatosis. One of them had also diabetes. Both patients showed a peculiar, striking lipodystrophic phenotype with subcutaneous lipoatrophy of the four limbs contrasting with truncal and abdominal fat accumulation. Their oral glucose tolerance tests showed extremely high levels of insulinemia, revealing major insulin resistance. Low serum levels of sex-hormone binding globulin and adiponectin suggested a post-receptor insulin signalling defect. Other clinical features included bilateral cataracts, greying hair and distal skin atrophy. We observed biallelic WRN null mutations in both women (p.Q748X homozygous, and compound heterozygous p.Q1257X/p.M1329fs). Their fertility was decreased, with preserved menstrual cycles and normal follicle-stimulating hormone levels ruling out premature ovarian failure. However undetectable anti-müllerian hormone and inhibin B indicated diminished follicular ovarian reserve. Insulin-resistance linked ovarian hyperandrogenism could also contribute to decreased fertility, and the two patients became pregnant after initiation of insulin-sensitizers (metformin). Both pregnancies were complicated by severe cervical incompetence, leading to the preterm birth of a healthy newborn in one case, but to a second trimester-abortion in the other. WRN -mutated fibroblasts showed oxidative stress, increased lamin B1 expression, nuclear dysmorphies and premature senescence. Conclusions We show here for the first time that partial lipodystrophy with severe insulin resistance can reveal WRN -linked premature aging syndrome. Increased expression of lamin B1 with altered lamina architecture observed in WRN -mutated fibroblasts could contribute to premature cellular senescence. Primary alterations in DNA replication and/or repair should be considered as possible causes of lipodystrophic syndromes.

Werner syndrome (WS), also known as adult progeria, is a rare autosomal recessive inherited progeroid syndrome characterised by multiple features consistent with accelerated ageing. This disease is associated with several rheumatic conditions such as early osteoarthritis and osteoporosis, sarcopenia, soft-tissue calcifications, gout, limb ulcers and scleroderma-like skin features. WS should be included in the differential diagnosis of systemic sclerosis. The diagnosis is clinical, and in 90% of cases, a genetic test reveals a pathogenic variant of the WRN gene. WRN encodes a member of the RecQ family of DNA helicases and has a role in DNA repair. 86 different pathological WRN mutations have been identified so far. Here we present a case report of a typical WS patient associated with a newly described genetic variant of the WRN gene.

Background Diabetes mellitus (DM) in children and adolescents is typically caused by type 1 DM, followed by type 2 DM and maturity‐onset diabetes of the young (MODY). We report an unusual Asian Indian family in which three members presented with DM at ages 15, 20, and 30, but not fitting the typical clinical picture of type 1 DM, type 2 DM, or MODY. The primary objective was to elucidate the molecular genetic basis of DM in this family. Methods The proband, a 22‐year‐old man, had short stature, gray hair, osteoporosis, and markedly reduced subcutaneous fat on the body, especially on the extremities along with acanthosis nigricans, and developed myxoid malignant peripheral nerve sheath tumor. Detailed family history revealed multiple loops of consanguinity. The proband underwent whole‐genome sequencing, and seven relatives underwent whole‐exome sequencing. Results The proband and three additional family members were found to have the homozygous c.561A>G nucleotide variant of WRN RecQ‐like helicase (WRN) gene consistent with the diagnosis of Werner's syndrome. The c.561A>G variant induces a new splicing site on exon 6 resulting in a truncated WRN protein, p.Lys187Trpfs*13. Conclusion Our report brings to attention the onset of DM during childhood or early adulthood in patients with Werner's syndrome who typically develop type 2 DM around the age of 30–40 years. Presence of consanguinity among parents, dysmorphic features, and malignancy should prompt consideration of diagnosis of Werner's syndrome.