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Journal of Mother and Child Mar 2022Joubert syndrome (JS; MIM PS213300) is a rare genetic autosomal recessive disease characterized by cerebellar vermis hypoplasia, a distinctive malformation of the... (Review)
Review
Joubert syndrome (JS; MIM PS213300) is a rare genetic autosomal recessive disease characterized by cerebellar vermis hypoplasia, a distinctive malformation of the cerebellum and the so-called "molar tooth sign." Other characteristic features are hypotonia with lateral ataxia, intellectual disability/mental retardation, oculomotor apraxia, retinal dystrophy, abnormalities in the respiratory system, renal cysts, hepatic fibrosis, and skeletal changes. Such pleiotropic characteristics are typical of many disorders involving primary cilium aberrations, providing a significant overlap between JS and other ciliopathies such as nephronophthisis, Meckel syndrome, and Bardet-Biedl syndrome. This review will describe some characteristics of JS associated with changes in 35 genes, and will also address subtypes of JS, clinical diagnosis, and the future of therapeutic developments.
Topics: Humans; Cerebellum; Abnormalities, Multiple; Eye Abnormalities; Retina; Polycystic Kidney Diseases; Intellectual Disability
PubMed: 36803942
DOI: 10.34763/jmotherandchild.20222601.d-22-00034 -
American Journal of Human Genetics Feb 2022Free oligosaccharides (fOSs) are soluble oligosaccharide species generated during N-glycosylation of proteins. Although little is known about fOS metabolism, the recent...
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.
Topics: Adolescent; Alleles; Brain Stem; Cell Line, Tumor; Central Nervous System Cysts; Cerebellar Vermis; Child; Child, Preschool; Congenital Disorders of Glycosylation; Female; Fetus; Glycosylation; Hamartoma; Humans; Hypothalamus; Intellectual Disability; Leukocytes; Male; Mannose; Oligosaccharides; Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase; Polymicrogyria; Tongue; alpha-Mannosidase
PubMed: 35045343
DOI: 10.1016/j.ajhg.2021.12.010 -
The Pan African Medical Journal 2012The cerebellar location of ganglioglioma (GG) is exceptional. We report one case of a 27-year-old man who underwent an intracranial hypertension syndrome and a static... (Review)
Review
The cerebellar location of ganglioglioma (GG) is exceptional. We report one case of a 27-year-old man who underwent an intracranial hypertension syndrome and a static cerebellar syndrome. Brain magnetic resonance images revealed a cyst image in the vermis. Histological study after surgical removal, revealed a ganglioglioma tumor. Through this case and literature review, the authors discuss some epidemiological, histological, clinical, radiological and management features of this very rare tumor.
Topics: Adult; Cerebellar Neoplasms; Ganglioglioma; Humans; Male
PubMed: 22826736
DOI: No ID Found -
American Journal of Medical Genetics.... Dec 2018Rhombencephalosynapsis (RES) is a unique cerebellar malformation characterized by fusion of the cerebellar hemispheres with partial or complete absence of a recognizable... (Review)
Review
Rhombencephalosynapsis (RES) is a unique cerebellar malformation characterized by fusion of the cerebellar hemispheres with partial or complete absence of a recognizable cerebellar vermis. Subsets of patients also have other brain malformations such as midbrain fusion with aqueductal stenosis, characteristic craniofacial features (prominent forehead, flat midface, hypertelorism, ear abnormalities), and somatic malformations (heart, kidney, spine, and limb defects). Similar to known genetic brain malformations, the RES cerebellar malformation is highly stereotyped, yet no genetic causes have been identified. Here, we outline our current understanding of the genetic basis for RES, discuss limitations, and outline future approaches to identifying the causes of this fascinating brain malformation.
Topics: Cerebellar Diseases; Cerebellum; Growth Disorders; Humans; Rhombencephalon
PubMed: 30580482
DOI: 10.1002/ajmg.c.31666 -
Neuroscience Research May 2024Anger transition is often abrupt. In this study, we investigated the mechanisms responsible for switching and modulating aggression levels. The cerebellum is considered...
Anger transition is often abrupt. In this study, we investigated the mechanisms responsible for switching and modulating aggression levels. The cerebellum is considered a center for motor coordination and learning; however, its connection to social behavior has long been observed. Here, we used the resident-intruder paradigm in male mice and examined local field potential (LFP) changes, glial cytosolic ion fluctuations, and vascular dynamics in the cerebellar vermis throughout various phases of a combat sequence. Notably, we observed the emergence of theta band oscillations in the LFP and sustained elevations in glial Ca levels during combat breakups. When astrocytes, including Bergmann glial cells, were photoactivated using channelrhodopsin-2, the theta band emerged and an early combat breakup occurred. Within a single combat sequence, rapid alteration of offensive (fight) and passive (flight) responses were observed, which roughly correlated with decreases and increases in glial Ca, respectively. Neuron-glial interactions in the cerebellar vermis may play a role in adjusting Purkinje cell excitability and setting the tone of aggression. Future anger management strategies and clinical control of excessive aggression and violent behavior may be realized by developing a therapeutic strategy that adjusts glial activity in the cerebellum.
Topics: Animals; Aggression; Male; Neuroglia; Mice; Cerebellum; Astrocytes; Mice, Inbred C57BL; Calcium
PubMed: 38007191
DOI: 10.1016/j.neures.2023.11.008 -
Schizophrenia Research Aug 2022Negative symptoms in the psychosis continuum are linked to impairments in reward processing and cognitive function. Processes at the interface of reward processing and...
Negative symptoms in the psychosis continuum are linked to impairments in reward processing and cognitive function. Processes at the interface of reward processing and cognition and their relation to negative symptoms remain little studied, despite evidence suggestive of integration in mechanisms and neural circuitry. Here, we investigated brain activation during reward-dependent modulation of working memory (WM) and their relationship to negative symptoms in subclinical and early stages of the psychosis continuum. We included 27 persons with high schizotypal personality traits and 23 patients with first episode psychosis as well as 27 healthy controls. Participants underwent functional magnetic resonance imaging while performing an established 2-back WM task with two reward levels (5 CHF vs. no reward), which allowed us to assess common reward-cognition regions through whole-brain conjunction analyses and to investigate relations with clinical scores of negative symptoms. As expected for behavior, reward facilitated performance while cognitive load diminished it. At the neural level, the conjunction of high reward and high cognitive load contrasts across the psychosis continuum showed increased hemodynamic activity in the thalamus and the cerebellar vermis. During high cognitive load, more severe apathy but not diminished expression in the psychosis continuum was associated with reduced activity in right lateral orbitofrontal cortex, midbrain, posterior vermal cerebellum, caudate and lateral parietal cortex. Our results suggest that hypoactivity in the cerebellar vermis and the cortical-striatal-midbrain-circuitry in the psychosis continuum relates to apathy possibly via impaired flexible cognitive resource allocation for effective goal pursuit.
Topics: Apathy; Cerebellum; Cognition; Humans; Magnetic Resonance Imaging; Mesencephalon; Psychotic Disorders
PubMed: 35728420
DOI: 10.1016/j.schres.2022.06.010