Leukoencephalopathy with calcifications and cysts: A case report with literature review.

Leukoencephalopathy with calcifications and cysts (LCC; OMIM #614561) is a rare disease and at present there are less than 100 cases reported worldwide. Mutations in the SNORD118 gene is now known to be the cause of LCC. We present a case who was heterozygous for the n.70G>A and n.6C>T sequence variants of the SNORD118 gene, variants which to date have not been described. Compared with the cases that we reviewed, our patient had the second longest time to diagnosis (age 56) from onset of symptoms 40 years prior. Moreover, his cousin's family has a high prevalence of epilepsy. This paper reviewed all published reports to date that had descriptive cases involving LCC as well as testing for the SNORD118 gene. Since 1996 only 85 patients have been described in 59 case reports. In this review, we summarize their clinical features, especially central nervous system symptoms, treatment, pathology, and gene testing results.

Diagnosis and Management of Pediatric Papillary Craniopharyngiomas.

OBJECTIVE: Papillary craniopharyngioma (PCP) was previously believed to occur only in adults. Sporadic pediatric PCP (PPCP) confirmed by detection of BRAF V600E mutation has been reported since 2018, but is often misdiagnosed before being diagnosed definitively. We aimed to evaluate PPCP characteristics and propose diagnostic criteria for prompt diagnosis, seeking to reduce patient morbidity and mortality and reduce costs linked to misdiagnosis. METHODS: This study included 5 patients with PPCPs whose data were retrieved retrospectively from among 1032 patients with craniopharyngiomas admitted to Sanbo Brain Hospital Management Group from March 2017 to May 2021. Patients' demographics, clinical presentation, tumor imaging characteristics, histopathologic results, surgical approaches, and postoperative outcomes were analyzed. RESULTS: PPCP was misdiagnosed intraoperatively as sellar abscess (n = 4) or Rathke cleft cyst (n = 1). Preoperative magnetic resonance imaging showed that all tumors were under the saddle diaphragm, and the cyst wall was enhanced (n = 5). Computed tomography scans showed scattered high-density signs (n = 4). No recurrence was noted after complete resection. Postoperative hypothalamic dysfunction was mild. BRAF V600E mutation was confirmed in all cases by sequencing and immunohistochemistry. Immunohistochemistry showed granulation and inflammation and MPO, CD3, CD20, CD38, CD68, and CD163 were positively expressed. CONCLUSIONS: Misdiagnosis of PPCP is responsible for failed surgical treatment. We propose that prompt diagnosis of PPCP can be achieved if preoperative magnetic resonance images show the tumor under saddle diaphragm with tumor wall enhancement and computed tomography scans show high-density signs scattered in the tumor, which leads to safe, effective tumor resection. Our proposed diagnosis and treatment strategy for PPCP reduces morbidity and mortality.

Coats plus in prematurity.

BACKGROUND: Coats plus syndrome or cerebroretinal microangiopathy with calcifications and cysts (CMCC) is an exceedingly rare autosomal recessive disorder that predominantly affects the microvasculature in the retina, brain, bones, and gastrointestinal system. Unlike Coats disease, CMCC is bilateral and affects multiple organ systems. MATERIALS AND METHODS: Case report. RESULTS: We report the case of two brothers with Coats Plus syndrome who presented with variable phenotypic expression. One sibling (Patient 1) was thought to have atypical retinopathy of prematurity and was only diagnosed with Coats plus after his older brother (Patient 2) presented with a seizure and a left upper extremity tremor at 4 years of age. The CTC1 mutation was confirmed in both patients. Aggressive treatment with laser photocoagulation and intravitreal bevacizumab dramatically improved the retinal vascular and exudative changes. CONCLUSION: Coats Plus syndrome can have a variable phenotypic presentation, including retinal vascular findings. This rare genetic disease should be in the differential diagnosis in patients who present with atypical retinal pathology, including Retinopathy of Prematurity, Familial Exudative Vitreoretinopathy, or Coats disease associated with non-specific multiorgan abnormalities.

Coats plus syndrome: a rare cause of severe gastrointestinal tract bleeding in children - a case report.

BACKGROUND: Coats plus syndrome, cerebroretinal microangiopathy with calcifications and cysts, is a rare disease with autosomal recessive pattern occurring due to a mutation in CTC1, encoding conserved telomere maintenance component 1, gene. Besides retinal involvement, abnormalities in brain and osteopenia, serious life-threatening bleeding in gastrointestinal tract and portal hypertension can be observed. CASE PRESENTATION: A 6-year-old girl with Coats plus syndrome presented to the pediatric emergency department with vomiting blood and blood in stool. An upper and lower gastrointestinal endoscopy revealed esophageal varices and vascular telangiectasia in the pyloric antrum, duodenum, and colon. She received palliative care and the bleeding was stopped after receiving intravenous octreotide. She then was followed in the pediatric gastroenterology, neurology, and ophthalmology clinics. She was later hospitalized and admitted to the intensive care unit as she continued to have intermittent gastrointestinal system bleeding. She eventually died due to severe gastrointestinal system bleeding. CONCLUSIONS: Coats plus syndrome can lead to life-threatening gastrointestinal bleeding and portal hypertension. As Coats plus syndrome is quite rare, there is little published data on this syndrome. This report presents a case of Coats plus syndrome as a rare cause of gastrointestinal bleeding and portal hypertension.

Leukoencephalopathy with brain calcifications and cysts (Labrune syndrome) case report: diagnosis and management of a rare neurological disease.

BACKGROUND: Leukoencephalopathy with brain calcifications and cysts (LCC; also known as Labrune syndrome) is a rare genetic microangiopathy caused by biallelic mutations in SNORD118. The mechanisms by which loss-of-function mutations in SNORD118 lead to the phenotype of leukoencephalopathy, calcifications and intracranial cysts is unknown. CASE PRESENTATION: We present the histopathology of a 36-year-old woman with ataxia and neuroimaging findings of diffuse white matter abnormalities, cerebral calcifications, and parenchymal cysts, in whom the diagnosis of LCC was confirmed with genetic testing. Biopsy of frontal white matter revealed microangiopathy with small vessel occlusion and sclerosis associated with axonal loss within the white matter. CONCLUSIONS: These findings support that the white matter changes seen in LCC arise as a consequence of ischemia rather than demyelination.

Impaired catabolism of free oligosaccharides due to MAN2C1 variants causes a neurodevelopmental disorder.

Free oligosaccharides (fOSs) are soluble oligosaccharide species generated during N-glycosylation of proteins. Although little is known about fOS metabolism, the recent identification of NGLY1 deficiency, a congenital disorder of deglycosylation (CDDG) caused by loss of function of an enzyme involved in fOS metabolism, has elicited increased interest in fOS processing. The catabolism of fOSs has been linked to the activity of a specific cytosolic mannosidase, MAN2C1, which cleaves α1,2-, α1,3-, and α1,6-mannose residues. In this study, we report the clinical, biochemical, and molecular features of six individuals, including two fetuses, with bi-allelic pathogenic variants in MAN2C1; the individuals are from four different families. These individuals exhibit dysmorphic facial features, congenital anomalies such as tongue hamartoma, variable degrees of intellectual disability, and brain anomalies including polymicrogyria, interhemispheric cysts, hypothalamic hamartoma, callosal anomalies, and hypoplasia of brainstem and cerebellar vermis. Complementation experiments with isogenic MAN2C1-KO HAP1 cells confirm the pathogenicity of three of the identified MAN2C1 variants. We further demonstrate that MAN2C1 variants lead to accumulation and delay in the processing of fOSs in proband-derived cells. These results emphasize the involvement of MAN2C1 in human neurodevelopmental disease and the importance of fOS catabolism.

Primary Ovarian Failure in Addition to Classical Clinical Features of Coats Plus Syndrome in a Female Carrying 2 Truncating Variants of CTC1.

Coats plus syndrome is an autosomal recessive multisystemic and pleiotropic disorder affecting the eyes, brain, bone, and gastrointestinal tract, usually caused by compound heterozygous variants of the conserved telomere maintenance component 1 gene (CTC1), involved in telomere homeostasis and replication. So far, most reported patients are compound heterozygous for a truncating mutation and a missense variant. The phenotype is believed to result from telomere dysfunction, with accumulation of DNA damage, cellular senescence, and stem cell depletion. Here, we report a 23-year-old female with prenatal and postnatal growth retardation, microcephaly, osteopenia, recurrent fractures, intracranial calcification, leukodystrophy, parenchymal brain cysts, bicuspid aortic valve, and primary ovarian failure. She carries a previously reported maternally inherited pathogenic variant in exon 5 (c.724_727del, p.(Lys242Leufs*41)) and a novel, paternally inherited splice site variant (c.1617+5G>T; p.(Lys480Asnfs*17)) in intron 9. CTC1 transcript analysis showed that the latter resulted in skipping of exon 9. A trace of transcripts was normally spliced resulting in the presence of a low level of wild-type CTC1 transcripts. We speculate that ovarian failure is caused by telomere shortening or chromosome cohesion failure in oocytes and granulosa cells, with early decrease in follicular reserve. This is the first patient carrying 2 truncating CTC1 variants and the first presenting primary ovarian failure.

Novel compound heterozygous STN1 variants are associated with Coats Plus syndrome.

AIM: Coats plus syndrome (CP) is a rare autosomal recessive disorder, characterised by retinal telangiectasia exudates (Coats disease), leukodystrophy, distinctive intracranial calcification and cysts, as well as extra-neurological features including abnormal vasculature of the gastrointestinal tract, portal hypertension and osteopenia with a tendency to fractures. CP most frequently occurs due to loss-of-function mutations in CTC1. The encoded protein CTC1 constitutes part of the CST (CTC1-STN1-TEN1) complex, and three patients have been described with CP due to biallelic mutations in STN1. Together with the identification of homozygosity for a specific loss-of-function mutation in POT1 in a sibling pair, these observations highlight a defect in the maintenance of telomere integrity as the cause of CP, although the precise mechanism leading to the micro-vasculopathy seen at a pathological level remains unclear. Here, we present the investigation of a fourth child who presented to us with retinal exudates, intracranial calcifications and developmental delay, in keeping with a diagnosis of CP, and later went on to develop pancytopenia and gastrointestinal bleeding. Genome sequencing revealed compound heterozygous variants in STN1 as the likely genetic cause of CP in this present case. METHODS: We assessed the phenotype to be CP and undertook targeted sequencing. RESULTS: Whilst sequencing of CTC1 and POT1 was normal, we identified novel compound heterozygous variants in STN1 (previous gene symbol OBFC1): one loss-of-function--c.894dup (p.(Asp299Argfs*58)); and one missense--c.707T>C (p.(Leu236Pro)). CONCLUSION: Given the clinical phenotype and identified variants we suggest that this is only the fourth patient reported to date with CP due to mutations in STN1.

Optimized photochemistry enables efficient analysis of dynamic RNA structuromes and interactomes in genetic and infectious diseases.

Direct determination of RNA structures and interactions in living cells is critical for understanding their functions in normal physiology and disease states. Here, we present PARIS2, a dramatically improved method for RNA duplex determination in vivo with >4000-fold higher efficiency than previous methods. PARIS2 captures ribosome binding sites on mRNAs, reporting translation status on a transcriptome scale. Applying PARIS2 to the U8 snoRNA mutated in the neurological disorder LCC, we discover a network of dynamic RNA structures and interactions which are destabilized by patient mutations. We report the first whole genome structure of enterovirus D68, an RNA virus that causes polio-like symptoms, revealing highly dynamic conformations altered by antiviral drugs and different pathogenic strains. We also discover a replication-associated asymmetry on the (+) and (-) strands of the viral genome. This study establishes a powerful technology for efficient interrogation of the RNA structurome and interactome in human diseases.

Ophthalmic findings and a novel CTC1 gene mutation in coats plus syndrome: a case report.

BACKGROUND: Coats plus syndrome is a rare multisystem disorder, and is also a telomere-related disorder caused by CTC1 gene mutation. We reported ophthalmic findings in a Chinese child with genetically confirmed Coats plus syndrome. MATERIALS AND METHODS: The comprehensive ophthalmic findings were presented, as well as treatment history and systemic manifestations. In addition, genetic testing was performed to confirm the diagnosis. RESULTS: Examination under anesthesia showed notable retinal vasculopathy, including vascular tortuosity and dilation, abnormal vascular anastomosis, retinal telangiectasias and mild exudation, extensive peripheral avascularity, as well as the presence of retinal neovascularization. The patient developed vitreous hemorrhage and tractional retinal detachment, and then underwent vitrectomy. Meanwhile, the patient was noted to have growth retardation and leukoencephalopathy. Gene testing identified a compound heterozygous mutation in CTC1 gene: a novel splicing site mutation (c.33 + 1 G > T) and a deletion mutation (c.2954_2956del, p.C985del), which were inherited from his mother and father, respectively. CONCLUSIONS: The present report expanded the genotype and phenotype spectrum of CTC1 gene associated with Coats plus syndrome.

Gastrointestinal Hemorrhage: A Manifestation of the Telomere Biology Disorders.

OBJECTIVE: To describe the clinical features, therapeutic interventions, and patient outcomes of gastrointestinal (GI) hemorrhage in individuals with a telomere biology disorder, including dyskeratosis congenita, Hoyeraal-Hreidarsson syndrome, Revesz syndrome, and Coats plus. STUDY DESIGN: Clinical Care Consortium for Telomere Associated Ailments members were invited to contribute data on individuals with telomere biology disorders at their institutions who experienced GI bleeding. Patient demographic, laboratory, imaging, procedural, and treatment information and outcomes were extracted from the medical record. RESULTS: Sixteen patients who experienced GI hemorrhage were identified at 11 centers. Among 14 patients who underwent genetic testing, 8 had mutations in TINF2, 4 had mutations in CTC1 or STN1, and 1 patient each had a mutation in TERC and RTEL1. Ten patients had a history of hematopoietic cell transplantation. The patients with Coats plus and those without Coats plus had similar clinical features and courses. Angiodysplasia of the stomach and/or small bowel was described in 8 of the 12 patients who underwent endoscopy; only 4 had esophageal varices. Various medical interventions were trialed. No single intervention was uniformly associated with cessation of bleeding, although 1 patient had a sustained response to treatment with bevacizumab. Recurrence was common, and the overall long-term outcome for affected patients was poor. CONCLUSIONS: GI bleeding in patients with telomere biology disorders is associated with significant morbidity and with vascular ectasias rather than varices.

An Indian child with Coats plus syndrome due to mutations in STN1.

The role of the CTC1-STN1-TEN1 (CST) complex in Coats plus syndrome (CP), as well as other telomeropathy-phenotypes and disorders of genome instability is well documented. We report an Indian child with a clinical diagnosis of CP who presented to us with retinal exudates, extensive cerebral calcification, developmental delay and severe anemia consequent upon chronic gastrointestinal (GI) bleeding. Whole exome sequencing revealed compound heterozygous variants in STN1 as the probable genetic cause leading to CP in the present case. Of the two variants, the nonsense variant c.397C>T (p.Arg133*) was a truncating variant leading to loss of full protein length whereas the second variant c.985G>C (p.Ala329Pro) was novel and neither reported in ExAC, 1KGP or gnomAD. The deleteriousness of the novel variant was explored through molecular dynamics simulation analysis where p.Ala329Pro mutation affected C-terminal domain interaction between STN1 and TEN1 complex. Hormonal therapy using ethinyl estradiol and norethisterone was apparently associated with a clinically useful, although poorly sustained, decrease in blood transfusion requirement in the proband.

18F-FDG PET/CT in Labrune Syndrome.

A 69-year-old woman presented with cognitive impairment related to attentive, executive, and mnemonic functions; progressive worsening of walking, speaking, writing, and reading ability; and double sphincter incontinence. Leukoencephalopathy, cystic lesions, and calcifications, suspected for Labrune syndrome, were observed at MRI and CT brain images. Generalized wave abnormalities were also visible at electroencephalogram. Functional brain imaging performed with F-FDG PET/CT demonstrated a decreased glucose metabolism in impaired brain regions, in accordance with MRI findings. Genetic testing confirmed a mutation of SNORD118.

A unique case of coats plus syndrome and dyskeratosis congenita in a patient with CTC1 mutations.

Coats plus syndrome (CP) is a rare condition characterized by bilateral exudative retinal telangiectasias with associated systemic disorders primarily affecting the brain, bone and gastrointestinal tract due to a mutation in the CTC1 gene. CTC1 mutations are also known to cause dyskeratosis congenita (DC), which is an inherited bone marrow failure syndrome characterized by skin pigmentation abnormalities, nail dystrophy, and oral leukoplakia. This is the first reported case of a patient diagnosed with both CP and DC caused by compound heterozygous CTC1 gene mutations. Moreover, one of the variant mutations found in this patient has never been published before.

Systemic involvement in adult-onset leukoencephalopathy with intracranial calcifications and cysts (Labrune syndrome) with a novel mutation of the SNORD118 gene.

BACKGROUND AND PURPOSE: Although Labrune syndrome is a well-known disorder characterized by a typical neuroradiological triad, namely leukoencephalopathy, intracranial calcifications and cysts, there are no reports of systemic involvement in this disorder. This paper attempts to describe a peculiar clinical manifestation related to a novel mutation in the SNORD118 gene. METHODS: Clinical examination, brain and total-body imaging, and neurophysiological and ophthalmological investigations were performed. Amplification of the SNORD118 gene and Sanger sequencing were integrated to investigate potential causative mutations. RESULTS: A 69-year-old woman, with a long history of episodes of vertigo and gait imbalance, was referred to our hospital for progressive cognitive and motor deterioration. Computed tomography and magnetic resonance imaging disclosed diffuse bilateral leukoencephalopathy in periventricular and deep white matter, widespread calcifications and numerous cysts in the brain, liver, pancreas and kidneys. The genetic analysis revealed two biallelic variants in the SNORD118 gene, one of which is novel (n.60G>C). CONCLUSIONS: This is the first report of adult-onset Labrune syndrome with an unusual systemic involvement presenting a novel mutation in the SNORD118 gene.

Rathke's cleft-like cysts arise from Isl1 deletion in murine pituitary progenitors.

The transcription factor ISL1 is expressed in pituitary gland stem cells and the thyrotrope and gonadotrope lineages. Pituitary-specific Isl1 deletion causes hypopituitarism with increased stem cell apoptosis, reduced differentiation of thyrotropes and gonadotropes, and reduced body size. Conditional Isl1 deletion causes development of multiple Rathke's cleft-like cysts, with 100% penetrance. Foxa1 and Foxj1 are abnormally expressed in the pituitary gland and associated with a ciliogenic gene-expression program in the cysts. We confirmed expression of FOXA1, FOXJ1, and stem cell markers in human Rathke's cleft cyst tissue, but not craniopharyngiomas, which suggests these transcription factors are useful, pathological markers for diagnosis of Rathke's cleft cysts. These studies support a model whereby expression of ISL1 in pituitary progenitors drives differentiation into thyrotropes and gonadotropes and without it, activation of FOXA1 and FOXJ1 permits development of an oral epithelial cell fate with mucinous cysts. This pituitary-specific Isl1 mouse knockout sheds light on the etiology of Rathke's cleft cysts and the role of ISL1 in normal pituitary development.

Phenotypic Variability in Leukoencephalopathy with Brain Calcifications and Cysts: Case Report of Siblings from an Irish Traveller Family with a Homozygous SNORD118 Mutation.

Leukoencephalopathy with brain calcifications and cysts (LCC) is a rare cerebral microangiopathy, the cause of which was recently determined to be recessively inherited mutations in the SNORD118 gene. We report the case of a 32-year-old Irish Traveller woman who presented to the emergency department in convulsive status epilepticus with abnormal neuroimaging features characteristic of LCC. Her medical history consisted of epilepsy, intellectual impairment, previous craniotomies for excision of cerebral cysts and resection of a tibial osteogenic sarcoma. Whole exome sequencing identified a previously described homozygous variant, NR_033294.1 n.*5C>G, in the 3' UTR of the SNORD118 gene. Her sister was subsequently found to be homozygous for the same variant but with a significantly milder clinical phenotype consisting of migraine without aura and mild, non-specific, cerebral white matter changes on neuroimaging. Knowledge of the existence of LCC within this population means that targeted genetic testing for this specific mutation should be considered in Irish Traveller patients presenting with the characteristic clinical and radiological features. Given the striking phenotypic variability seen within this family, LCC should also be considered in Irish Traveller patients even in the absence of the complete radiological triad.

Analysis of U8 snoRNA Variants in Zebrafish Reveals How Bi-allelic Variants Cause Leukoencephalopathy with Calcifications and Cysts.

How mutations in the non-coding U8 snoRNA cause the neurological disorder leukoencephalopathy with calcifications and cysts (LCC) is poorly understood. Here, we report the generation of a mutant U8 animal model for interrogating LCC-associated pathology. Mutant U8 zebrafish exhibit defective central nervous system development, a disturbance of ribosomal RNA (rRNA) biogenesis and tp53 activation, which monitors ribosome biogenesis. Further, we demonstrate that fibroblasts from individuals with LCC are defective in rRNA processing. Human precursor-U8 (pre-U8) containing a 3' extension rescued mutant U8 zebrafish, and this result indicates conserved biological function. Analysis of LCC-associated U8 mutations in zebrafish revealed that one null and one functional allele contribute to LCC. We show that mutations in three nucleotides at the 5' end of pre-U8 alter the processing of the 3' extension, and we identify a previously unknown base-pairing interaction between the 5' end and the 3' extension of human pre-U8. Indeed, LCC-associated mutations in any one of seven nucleotides in the 5' end and 3' extension alter the processing of pre-U8, and these mutations are present on a single allele in almost all individuals with LCC identified to date. Given genetic data indicating that bi-allelic null U8 alleles are likely incompatible with human development, and that LCC is not caused by haploinsufficiency, the identification of hypomorphic misprocessing mutations that mediate viable embryogenesis furthers our understanding of LCC molecular pathology and cerebral vascular homeostasis.

Low-grade developmental and epilepsy associated brain tumors: a critical update 2020.

Brain tumors represent the second most frequent etiology in patients with focal seizure onset before 18 years of age and submitted to epilepsy surgery. Hence, this category of brain tumors, herein defined as low-grade, developmental, epilepsy-associated brain tumors (LEAT) is different from those frequently encountered in adults as (A): 77% of LEAT occur in the temporal lobe; (B): the vast majority of LEAT are of low malignancy and classified as WHO I°; (C): LEAT are often composed of mixed glial and neuronal cell components and present with variable growth patterns including small cysts or nodules; (D): LEAT do not share common gene driving mutations, such as IDH1 or 1p/19q co-deletions. Characteristic entities comprise the ganglioglioma (GG), the dysembryoplastic neuroepithelial tumor (DNT), the angiocentric glioma (AG), the isomorphic diffuse glioma (IDG) and the papillary glio-neuronal tumor (PGNT), representing 73.2% of 1680 tumors collected in a large German series of 6747 patients submitted to epilepsy surgery. In the realm of exciting discoveries of genetic drivers of brain tumors new genes have been also reported for LEAT. BRAF V600E mutations were linked to GG with CD34 expression, FGFR1 mutations to DNT, MYB alterations to AG and also IDG and PRKCA fusions to PGNT, suggesting the possibility to also develop a genetically driven tumor classification scheme for LEAT. Rare availability of LEAT in a single center is a challenging obstacle, however, to systematically unravel the neurobiological nature and clinical behavior of LEAT. Other challenges in need of clarification include malignant tumor progression of LEAT entities, seizure relapse in patients following bulk tumor resection and the controversial issue of associated focal cortical dysplasia as additional pathomechanism. In order to advance our understanding and promote reliable diagnostic work-up of LEAT, we recommend, therefore, international collaboration to achieve our goals.