[Behçet's and Cogan's syndromes - The Variable Vessel Vasculitides]. / Behçet- und Cogan-Syndrom.

Behçet's syndrome and Cogan's syndrome constitute the group of variable vessel vasculitides in the Chapel-Hill Nomenclature. They involve arteries and veins of all sizes. As reflected in the name "syndrome", both diseases can manifest with different individual symptoms. Both formally are rare diseases, but the Cogan syndrome is much rarer than Behçet`s. For the latter, there are diagnosis and classification criteria as well as European (EULAR, European Alliance of Associations for Rheumatology) treatment recommendations. The symptomatology, diagnostic measures and treatment as well as some considerations about pathogenesis will be discussed in this article.

The atypical sphingolipid SPB 18:1(14Z);O2 is a biomarker for DEGS1 related hypomyelinating leukodystrophy.

Sphingolipids (SL) represent a structurally diverse class of lipids that are central to cellular physiology and neuronal development and function. Defects in the sphingolipid metabolism are typically associated with nervous system disorders. The C4-dihydroceramide desaturase (DEGS1) catalyzes the conversion of dihydroceramide to ceramide, the final step in the SL de-novo synthesis. Loss of function mutations in DEGS1 cause a hypomyelinating leukodystrophy, which is associated with increased plasma dihydrosphingolipids (dhSL) and with the formation of an atypical SPB 18:1(14Z);O2 metabolite. Here, we characterize two novel DEGS1 variants of unknown significance (VUS), provide a structural model with a predicted substrate binding site, and propose a regulatory link between DEGS1 and fatty acid desaturase 3 (FADS3). Both VUS involve single amino acid substitutions near the C-terminus within conserved regions of the enzyme. Patient 1 (p.R311K variant) shows severe progressive tetraspasticity, intellectual disability, and epilepsy in combination with brain magnetic resonance imaging (MRI) findings, typical for DEGS1-related leukodystrophy. Patient 2 (p.G270E variant) presents with delayed psychomotor development, oculomotor apraxia, and a normal brain MRI. Plasma from the p.R311K carrier showed a significantly elevated dhSL species and the presence of SPB 18:1(14Z);O2, while the plasma SL profile for the p.G270E variant was not altered. This suggests the p.R331K variant is pathogenic, while the p.G270E appears benign. As an increase in dihydroSL species is also seen in other pathological disorders of the SL metabolism, the SPB 18:1(14Z);O2 seems to be a more specific biomarker to discriminate between pathogenic and benign DEGS1 variants.

XRCC1 mutation is associated with PARP1 hyperactivation and cerebellar ataxia.

XRCC1 is a molecular scaffold protein that assembles multi-protein complexes involved in DNA single-strand break repair. Here we show that biallelic mutations in the human XRCC1 gene are associated with ocular motor apraxia, axonal neuropathy, and progressive cerebellar ataxia. Cells from a patient with mutations in XRCC1 exhibited not only reduced rates of single-strand break repair but also elevated levels of protein ADP-ribosylation. This latter phenotype is recapitulated in a related syndrome caused by mutations in the XRCC1 partner protein PNKP and implicates hyperactivation of poly(ADP-ribose) polymerase/s as a cause of cerebellar ataxia. Indeed, remarkably, genetic deletion of Parp1 rescued normal cerebellar ADP-ribose levels and reduced the loss of cerebellar neurons and ataxia in Xrcc1-defective mice, identifying a molecular mechanism by which endogenous single-strand breaks trigger neuropathology. Collectively, these data establish the importance of XRCC1 protein complexes for normal neurological function and identify PARP1 as a therapeutic target in DNA strand break repair-defective disease.

Cogan's syndrome is more than just keratitis: a case-based literature review.

BACKGROUND: Cogan's syndrome (CS) is a rare autoimmune disorder characterized by non-syphilitic interstitial keratitis (IK) and Menière-like cochlear vestibular symptoms, which may also have systemic effects. Corticosteroids are first-line treatment. DMARDs and biologics have been used to treat ocular and systemic symptoms of CS. CASE PRESENTATION: This is a case of a 35-year-old female who reported hearing loss, eye redness and photophobia. Her condition progressed to a sudden sensorineural hearing loss, tinnitus, and constant vertigo accompanied by cephalea. CS was diagnosed after excluding other diseases. The patient still developed bilateral sensorineural hearing loss after receiving hormone, methotrexate, cyclophosphamide, and a variety of biological agents. Joint symptoms were relieved after treatment with a JAK inhibitor (tofacitinib), and hearing did not deteriorate further. CONCLUSIONS: CS should be involved in the differential diagnosis of keratitis. Early identification and intervention of this autoimmune disease can minimize disability and irreversible damage.

Clinical and Genetic Characterization of Brazilian Patients with Ataxia and Oculomotor Apraxia.

BACKGROUND: Ataxia with oculomotor apraxia (AOA) is characterized by early-onset cerebellar ataxia associated with oculomotor apraxia. AOA1, AOA2, AOA3, and AOA4 subtypes may present pathogenic variants in APTX, SETX, PIK3R5, and PNKP genes, respectively. Mutations in XRCC1 have been found to cause autosomal recessive spinocerebellar ataxia-26 (SCAR26) now considered AOA5. OBJECTIVES: To examine a cohort of Brazilians with autosomal recessive cerebellar ataxia plus oculomotor apraxia and determine the frequencies of AOA subtypes through genetic investigation. METHODS: We evaluated clinical, biomarkers, electrophysiological, and radiological findings of 52 patients with AOA phenotype and performed a genetic panel including APTX, SETX, PIK3R5, PNKP, and XRCC1. RESULTS: We found pathogenic variants in SETX (15 patients), PNKP (12), and APTX (5). No mutations in PIK3R5 or XRCC1 were identified. CONCLUSIONS: AOA2 and AOA4 were the most common forms of AOA in Brazil. Mutations in PIK3R5 and XRCC1 were not part of this genetic spectrum. © 2022 International Parkinson and Movement Disorder Society.

Acute ischemic stroke in a patient with Cogan's syndrome.

Cogan's syndrome is a rare disorder characterized by inflammatory eye and inner ear/vestibular disease. In some cases patients may present medium and large vessel vasculitis which may produce neurological manifestations. We present the case of a patient who was admitted with clinical manifestations of stroke. After intense study, Cogan's syndrome was diagnosed and treated.

[Atypical Cogan syndrome as a differential diagnosis of sudden sensorineural hearing loss]. / Atypisches Cogan-Syndrom als Differenzialdiagnose eines Hörsturzes.

Cogan I syndrome is a rare disease consisting of vestibulocochlear symptoms and non-syphilitic interstitial keratitis. Although this disease was first described in 1945, its pathogenesis is still unknown. An autoimmune vasculitis etiology is currently discussed. Atypical manifestations are characterized by delayed ocular symptoms or variability of inflammatory eye symptoms. Physical examination often reveals bilateral sensorineural hearing loss. Intratympanic corticosteroid application can be successful.

[Clinical and morphological characteristics of corneal epithelial dystrophy (clinical observations)]. / Kliniko-morfologicheskie kharakteristiki epitelial'noi distrofii rogovitsy (klinicheskie nablyudeniya).

This paper presents clinical observations that can be regarded as degeneration of the basement membrane of the corneal epithelium. Difficulties in identifying such forms of corneal dystrophies, on the one hand, are associated with limitation and polymorphism of the clinical picture, and, on the other hand, with insufficient information content of the basic diagnostic methods (i.e. the methods used during the initial examination). The presented clinical cases allow singling out the alarming and pathognomonic signs of the disease in the diagnostic algorithm. In the first case, attention should be paid to biomicroscopic changes in the superficial layers of the cornea and the optical defects, which can be regarded as a manifestation of an irregularity of corneal refraction. Identification of pathognomonic signs of the disease is possible on the basis of a detailed, close-to-morphological study of the structure of superficial corneal layers using confocal microscopy and optical coherence tomography. At the same time, the localization of the detected changes at the level of epithelial basement membrane and its basal sections is of crucial significance for substantiating the diagnosis. In addition, according to the literature data, recurrent erosions of the cornea of unclear etiology should be attributed to presumptive signs of degenerative changes in the basement membrane of the epithelium.

Heterozygous truncating variants in SUFU cause congenital ocular motor apraxia.

PURPOSE: This study aimed to delineate the genetic basis of congenital ocular motor apraxia (COMA) in patients not otherwise classifiable. METHODS: We compiled clinical and neuroimaging data of individuals from six unrelated families with distinct clinical features of COMA who do not share common diagnostic characteristics of Joubert syndrome or other known genetic conditions associated with COMA. We used exome sequencing to identify pathogenic variants and functional studies in patient-derived fibroblasts. RESULTS: In 15 individuals, we detected familial as well as de novo heterozygous truncating causative variants in the Suppressor of Fused (SUFU) gene, a negative regulator of the Hedgehog (HH) signaling pathway. Functional studies showed no differences in cilia occurrence, morphology, or localization of ciliary proteins, such as smoothened. However, analysis of expression of HH signaling target genes detected a significant increase in the general signaling activity in COMA patient-derived fibroblasts compared with control cells. We observed higher basal HH signaling activity resulting in increased basal expression levels of GLI1, GLI2, GLI3, and Patched1. Neuroimaging revealed subtle cerebellar changes, but no full-blown molar tooth sign. CONCLUSION: Taken together, our data imply that the clinical phenotype associated with heterozygous truncating germline variants in SUFU is a forme fruste of Joubert syndrome.

Atypical Cogan Syndrome Featuring Orbital Myositis and Dacryoadenitis.

A 39-year-old male presented with bilateral hearing loss and progressive left eye vision loss over a 14-month period. The development of systemic symptoms including arthralgias, enlarged lymph nodes, and profound leg weakness, prompted a workup for lymphoproliferative disease, infection, and autoimmune inflammatory conditions which was unrevealing. Subsequently, the right visual acuity declined from 20/25 to 20/70 and the left to hand motions due to corneal interstitial keratitis. There was limitation of left infraduction. Neuroimaging revealed dural thickening of the internal auditory canals, cavernous sinuses, cerebellum, and along the optic nerves. There was fusiform enhancing enlargement of the left inferior and medial rectus muscles and pathologic enlargement of the left lacrimal gland. Biopsy of the left lacrimal gland and left inferior rectus revealed fibrosis and lymphocytic infiltration. The patient was diagnosed with atypical Cogan syndrome and treated with oral prednisone, with improvement in visual acuity of the right eye, motility of the left eye, and systemic weakness.

Autosomal Recessive Cerebellar Ataxias With Elevated Alpha-Fetoprotein: Uncommon Diseases, Common Biomarker.

alpha-Fetoprotein (AFP) is a biomarker of several autosomal recessive cerebellar ataxias (ARCAs), especially ataxia telangiectasia (AT) and ataxia with oculomotor apraxia (AOA) type 2 (AOA2). More recently, slightly elevated AFP has been reported in AOA1 and AOA4. Interestingly, AOA1, AOA2, AOA4, and AT are overlapping ARCAs characterized by oculomotor apraxia, with oculocephalic dissociation, choreo-dystonia, and/or axonal sensorimotor neuropathy, in addition to cerebellar ataxia with cerebellar atrophy. The genetic backgrounds in these disorders play central roles in nuclear maintenance through DNA repair [ATM (AT), APTX (AOA1), or PNKP (AOA4)] or RNA termination [SETX (AOA2)]. Partially discriminating thresholds of AFP have been proposed as a way to distinguish between ARCAs with elevated AFP. In these entities, elevated AFP may be an epiphenomenon as a result of liver transcriptional dysregulation. AFP is a simple and reliable biomarker for the diagnosis of ARCA in performance and interpretation of next-generation sequencing. Here, we evaluated clinical, laboratory, imaging, and molecular data of the group of ARCAs that share elevated AFP serum levels that have been described in the past two decades. © 2020 International Parkinson and Movement Disorder Society.

Cogan's Syndrome: Clinical Presentations and Update on Treatment.

PURPOSE OF REVIEW: Cogan's syndrome (CS) is a rare systemic vasculitis that can severely affect vision and hearing, which may also have significant systemic effects. Early recognition of this autoimmune disorder and intervention can minimize disabling and irreversible damage. RECENT FINDINGS: This article will review the varying clinical presentations of CS and emerging information of systemic disease associated with CS. We will also review recently published promising treatment outcomes using immune modulating medications. As our framework for recognizing the markers of CS and the associated systemic disorders expands, more effective guidelines and treatment options may emerge.

Asymmetric Bálint's syndrome with multimodal agnosia, bilateral agraphesthesia, and ineffective kinesthetic reading due to subcortical hemorrhage in the left parieto-occipito-temporal area.

We report a patient with asymmetric Bálint's syndrome (predominantly right-sided oculomotor apraxia and simultanagnosia and optic ataxia for the right hemispace), and multimodal agnosia (apperceptive visual agnosia and bilateral associative tactile agnosia) with accompanying right hemianopia, bilateral agraphesthesia, hemispatial neglect, global alexia with unavailable kinesthetic reading, and lexical agraphia for kanji (Japanese morphograms), after hemorrhage in the left parieto-occipito-temporal area. The coexistence of tactile agnosia, bilateral agraphesthesia, and ineffective kinesthetic reading suggests that tactile-kinesthetic information can be interrupted because of damage to the fiber connection from the parietal lobe to the occipito-temporal area, leading to these tactually related cognitive impairments.

[Syncope, pain in the large joints, and painful swelling of the right eye in a 51-year-old patient : Pitfalls in the diagnosis and treatment of a rare disease]. / Synkope, Schmerzen der großen Gelenke und schmerzhafte Rötung des rechten Auges bei einer 51-jährigen Patientin : Fallstricke in Diagnostik und Therapie einer seltenen Erkrankung.

In the present case we report on a 51-year-old patient diagnosed with Cogan syndrome. This vasculitis of variable vessel size is a rare disease that poses a major challenge for the correct diagnostics and therapy. In the classic setting, it comprises a triad of non-syphilitic interstitial keratitis as well as hearing loss with vestibular dysfunction. A vascultis-related aortitis, an uncertain, more likely degenerative structure in combination with strongly elevated inflammation parameters was misinterpreted as infective endocarditis for a long time and treated with anti-infective medications. After diagnosis the patient recovered following treatment with high-dose steroids and in the further course cyclophosphamide and tumor necrosis factor­α blockers.

Germ cell arrest associated with aSETX mutation in ataxia oculomotor apraxia type 2.

Ataxia with oculomotor apraxia type 2 (AOA2) is a rare autosomal recessive neurodegenerative disorder characterized by cerebellar atrophy, peripheral neuropathy and oculomotor apraxia. It is caused by mutations in the SETX gene that encodes senataxin, a ubiquitously expressed protein that mediates processes, including transcription, transcription termination, DNA repair, RNA processing, DNA-RNA hybrid (R-loop) elimination and telomere stability. In mice, senataxin is essential for male germ cell development and fertility through its role in meiotic recombination and sex chromosome inactivation. AOA2 is associated with hypogonadism in women, but there are no reports of hypogonadism or infertility in men. We describe the first case of human male infertility caused by germ cell arrest in a man with AOA2. Our patient has a homozygous mutation in the SETX gene (NC_000009.11:g.135158775dup), which results in a frameshift and premature protein termination (NM_015046.6:c.6422dup, p.[Ser2142Glufs*23]). In accordance with the murine phenotype, testis histology revealed disrupted seminiferous tubules with spermatogonia and primary spermatocytes, but absent spermatids. Collectively, these data support an essential role of senataxin in human spermatogenesis, and provide a compelling case that men with AOA2 should be counselled at diagnosis about the possibility of infertility.

Aortic valve perforation in the setting of Cogan's syndrome.

Cogan's syndrome is a rare disorder characterized by the coexistence of ocular and audio-vestibular manifestations. Systemic manifestations are quite unusual with pan-vasculitis and cardiac involvement reported in the form of aortitis with aortic aneurysm, dissection, or extremely rare aortic valve perforation. Hereby, we report a case of a 56-year-old woman presented with ocular, audio-vestibular, and systemic manifestations with medium-sized vasculitis in the form of multiple splenic artery aneurysms, superior mesenteric artery thrombosis, and cardiovascular involvement in the form of aortic regurgitation due to noncoronary cusp perforation. To the best of our knowledge, this is the second case to report aortic perforation in the setting of Cogan's syndrome.

Cogan syndrome: An autoimmune eye and ear disease with systemic manifestations.

Cogan syndrome (CS) is a rare vasculitis seen primarily in young adults. It predominantly affects eyes, ears and the heart with characteristic findings of interstitial keratitis, sensorineural hearing loss and vestibular dysfunction. A high index of suspicion is required to diagnose this rare disorder. It is one of the few vasculitis which can involve vessels of all sizes: small, medium and large. Coexistence of inflammatory bowel disease (IBD) in Cogan syndrome has been described in the literature. Immunosuppressive agents such as corticosteroids with or without steroid sparing agents are the standard of care. Early diagnosis and treatment are the cornerstone of treatment to prevent permanent damage to the ears and eyes. We describe a patient with Cogan syndrome with large vessel vasculitis and IBD. Our patient was treated with glucocorticoids and methotrexate.

Mutations in PNKP cause recessive ataxia with oculomotor apraxia type 4.

Hereditary autosomal-recessive cerebellar ataxias are a genetically and clinically heterogeneous group of disorders. We used homozygosity mapping and exome sequencing to study a cohort of nine Portuguese families who were identified during a nationwide, population-based, systematic survey as displaying a consistent phenotype of recessive ataxia with oculomotor apraxia (AOA). The integration of data from these analyses led to the identification of the same homozygous PNKP (polynucleotide kinase 3'-phosphatase) mutation, c.1123G>T (p.Gly375Trp), in three of the studied families. When analyzing this particular gene in the exome sequencing data from the remaining cohort, we identified homozygous or compound-heterozygous mutations in five other families. PNKP is a dual-function enzyme with a key role in different pathways of DNA-damage repair. Mutations in this gene have previously been associated with an autosomal-recessive syndrome characterized by microcephaly; early-onset, intractable seizures; and developmental delay (MCSZ). The finding of PNKP mutations associated with recessive AOA extends the phenotype associated with this gene and identifies a fourth locus that causes AOA. These data confirm that MCSZ and some forms of ataxia share etiological features, most likely reflecting the role of PNKP in DNA-repair mechanisms.