Leukoencephalopathy with calcifications and cysts (LCC): 5 cases and literature review

Uncommon Causes of Nontraumatic Intracerebral Hemorrhage

Nontraumatic intracerebral hemorrhage is an important health issue. Although common causes such as hypertension and cerebral amyloid angiopathy predominantly affect the elderly, there exists a spectrum of uncommon etiologies that contribute to the overall incidence of intracerebral hemorrhage. The identification of these rare causes is essential for targeted clinical management, informed prognostication, and strategic secondary prevention where relevant. This topical review explores the uncommon intracerebral hemorrhage causes and provides practical clues for their clinical and imaging identification. By expanding the clinician's differential diagnosis, this review aims to bridge the gap between standard intracerebral hemorrhage classification systems and the nuanced reality of clinical practice.

Expanding the Natural History of SNORD118-Related Ribosomopathy: Hints from an Early-Diagnosed Patient with Leukoencephalopathy with Calcifications and Cysts and Overview of the Literature

Leukoencephalopathy with calcifications and cysts (LCC) is a rare autosomal recessive disorder showing a pediatric or adult onset. First described in 1996 by Labrune and colleagues, it was only in 2016 that bi-allelic variants in a non-protein coding gene, SNORD118, were found as the cause for LCC, differentiating this syndrome from coats plus (CP). SNORD118 transcribes for a small nucleolar RNA, which is necessary for correct ribosome biogenesis, hence the classification of LCC among ribosomopathies. The syndrome is characterized by a combination of white matter hyperintensities, calcifications, and cysts on brain MRI with varying neurological signs. Corticosteroids, surgery, and recently bevacizumab, have been tried with unclear results since the natural history of the disease remains elusive. To date, 67 patients with a pediatric onset of disease have been described in the literature, with a clinical-radiological follow-up carried out in only eleven of them. We described the clinical-radiological follow-up from birth to almost five years of age of a late-preterm patient diagnosed with LCC and carried out a thorough overview of pediatric patients described in the literature. It is important to gather serial clinical-radiological data from other patients to depict the natural history of this disease, aiming to deeply depict genotype-phenotype correlations and make the role of new therapeutics clearer.

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.

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.

Paediatric neurosurgical implications of a ribosomopathy: illustrative case and literature review

Ribosomopathies are rare, recently defined entities. One of these, Labrune syndrome, is recognisable radiologically by its distinctive triad of leukoencephalopathy, intracranial calcifications and cysts (LCC). These cysts may have neurosurgical implications at different ages because of their progressive expansion and local mass effect. The aetiology of LCC is related to a widespread cerebral microangiopathy and is due to a genetic mutation in SNORD118, responsible for stabilisation of the large ribosomal subunit during assembly.

Autosomal recessive adult onset ataxia

Autosomal recessive ataxias (ARCA) represent a complex group of diseases ranging from primary ataxias to rare and complex metabolic disorders in which ataxia is a part of the clinical picture. Small number of ARCA manifest exclusively in adulthood, while majority of typical childhood onset ARCA may also start later with atypical clinical presentation. We have systematically searched the literature for ARCA with adult onset, both in the group of primary ataxias including those that are less frequently described in isolated or in a small number of families, and also in the group of complex and metabolic diseases in which ataxia is only part of the clinical picture. We propose an algorithm that could be used when encountering a patient with adult onset sporadic or recessive ataxia in whom the acquired causes are excluded. ARCA are frequently neglected in the differential diagnosis of adult-onset ataxias. Rising awareness of their clinical significance is important, not only because some of these disorders may be potentially treatable, but also for prognostic implications and inclusion of patients to future clinical trials with disease modifying agents.

Neuroimaging findings in leukoencephalopathy with calcifications and cysts: case report and review of the literature

Leukoencephalopathy with cerebral calcifications and cysts (LCC) is a neurological disorder characterized by the radiological triad of white matter abnormalities, intracranial calcifications and cystic lesions variable in size resulting from a diffuse cerebral microangiopathy. Typically, progressive focal neurological deficits and seizures are the first clinical manifestation, but the severity of symptoms can vary according to the size and location of the cystic lesions holding compressive effects on the surrounding brain tissue. The most common histopathological finding is diffuse microangiopathy, which might be associated to pathogenic mutations in SNORD118 gene causing Labrune syndrome. Similar neuroradiological appearances have been found in the Coats plus syndrome, a systemic disorder caused by a genetic diffuse microangiopathy that affects not only the brain but also the retina and multiple organs, with a more complex clinical picture that address the diagnosis; biallelic mutations in CTC1 gene, encoding the conserved telomere maintenance component 1 (CTC1), are responsible of this systemic disorder. The aim of this contribution is to review the existing literature focusing on the neuroimaging characteristics by reporting cases in which radiological findings were highly suggestive for LCC.

Case Report: Clinical Features of Childhood Leukoencephalopathy With Cerebral Calcifications and Cysts Due to SNORD118 Variants

Background: Leukoencephalopathy with cerebral calcifications and cysts (LCC) is a rare autosomal recessive cerebral microangiopathy. Recently, biallelic variants in a non-protein-coding gene SNORD118 have been discovered to cause LCC.

Case Presentation: We here report a genetically confirmed childhood case of LCC. The patient was a 4-year-and-1-month-old boy with focal seizures. The age at onset of his seizure was 10 days after birth. The seizures were well-controlled by antiepileptic treatment but reoccurred twice due to a head impact accident and a fever, respectively. He suffered from a self-limited esotropia and unsteady running gait during the seizure onset. He had the typical neuroimaging triad of multifocal intracranial calcifications, cysts, and leukoencephalopathy. Genetic analysis indicated that he carried compound heterozygous variants of n.^*9C>T and n.3C>T in SNORD118, which were inherited from his parents.

Conclusion: We report a childhood LCC case with compound heterozygous variants in SNORD118. To the best of our knowledge, the patient reported in our case had the youngest onset age of LCC with a determined genotype. The triad cerebral-imaging findings of calcifications, cysts, and leukoencephalopathy provide a crucial diagnostic basis. Moreover, the gene assessment, together with the clinical investigations, should be considered for the diagnosis of LCC.

Surgical considerations in Labrune syndrome

PURPOSE

Labrune syndrome (LS) is a rare white matter disease characterized by leukoencephalopathy with intracranial calcification and cysts (LCC). While the intracranial cyst characteristics of LS are for the most part stable, some may require surgical intervention when they develop associated hemorrhage and/or mass effect. To date, no review of the surgical outcomes of cyst decompression in LS has been performed.

CASE PRESENTATION

We report the case of a 16-year-old girl with LS who presented with progressive right hemiparesis from an enlarging hemorrhagic left thalamic cyst. The patient underwent frameless stereotactic cyst aspiration and Ommaya reservoir placement and her hemiparesis subsequently improved. Serial monitoring demonstrated stable decompression of the cyst.

CONCLUSIONS

The pathophysiology of LS is thought to be diffuse cerebral microangiopathy and it is thought that these microhemorrhages contribute to the formation of intracranial cysts as well as diffuse calcifications. Indications for surgical intervention in LS are not well established and the heterogeneity of lesions compels them to be managed on a case-by-case basis. Based on our literature review, surgery is the standard treatment of choice for patients with progressive symptoms and growing lesions on imaging studies, with outcomes favoring less-invasive stereotactic approaches with contingencies of reservoir placement when cysts recur.

Leukoencephalopathy with calcifications and cysts: Genetic and phenotypic spectrum

Biallelic mutations in SNORD118, encoding the small nucleolar RNA U8, cause leukoencephalopathy with calcifications and cysts (LCC). Given the difficulty in interpreting the functional consequences of variants in nonprotein encoding genes, and the high allelic polymorphism across SNORD118 in controls, we set out to provide a description of the molecular pathology and clinical spectrum observed in a cohort of patients with LCC. We identified 64 affected individuals from 56 families. Age at presentation varied from 3 weeks to 67 years, with disease onset after age 40 years in eight patients. Ten patients had died. We recorded 44 distinct, likely pathogenic, variants in SNORD118. Fifty two of 56 probands were compound heterozygotes, with parental consanguinity reported in only three families. Forty nine of 56 probands were either heterozygous (46) or homozygous (three) for a mutation involving one of seven nucleotides that facilitate a novel intramolecular interaction between the 5' end and 3' extension of precursor-U8. There was no obvious genotype-phenotype correlation to explain the marked variability in age at onset. Complementing recently published functional analyses in a zebrafish model, these data suggest that LCC most often occurs due to combinatorial severe and milder mutations, with the latter mostly affecting 3' end processing of precursor-U8.

Leukoencephalopathy with Calcifications and Cysts—The First Polish Patient with Labrune Syndrome

Leukoencephalopathy with calcifications and cysts (LCC) is a triad of neuroradiological symptoms characteristic of Labrune syndrome, which was first described in 1996. For 20 years, the diagnosis was only based on clinical, neuroradiological and histopathological findings. Differential diagnosis included a wide spectrum of diseases. Finally, in 2016, genetic mutation in the SNORD118 gene was confirmed to cause Labrune syndrome. The authors describe a case of a teenage girl with progressive headaches, without developmental delay, presenting with calcifications and white matter abnormality in neuroimaging. Follow-up studies showed the progression of leukoencephalopathy and cyst formation. The first symptoms and initial imaging results posed diagnostic challenges. The final diagnosis was established based on genetic results. The authors discuss the possible therapy of LCC with Bevacizumab.