39 research outputs found
Cavitating Leukoencephalopathy With Posterior Predominance Caused by a Deletion in the APOPT1 Gene in an Indian Boy.
A 5-year-old Indian boy presented with subacute onset regression of milestones associated with seizures and spasticity. The symptoms started after an attack of measles. The magnetic resonance imaging (MRI) of the brain showed cavitating leukodystrophy with posterior predominance. Molecular analysis of the APOPT1 gene, a recently described gene associated with mitochondrial leukodystrophy, showed the patient to be homozygous for a 12.82-kilobase deletion, including coding exon 3. Deletion of exon 3 produces a frameshift, predicting the translation of a truncated protein (p.Glu121Valfs*4). The patient was started on mitochondrial cocktail regimen of thiamine, riboflavin, coenzyme Q and carnitine. Although he initially showed some improvement, he died 6 months after the onset of his illness.Genetic testing for the patient was done as part of the APOPT1 research project funded by MRC (MRC-QQR grant 2015-2020 and ERC advanced
grant ERC FP7-322424
Metamagnetic Quantum Criticality in Sr3Ru2O7
We consider the metamagnetic transition in the bilayer ruthenate, , and use this to motivate a renormalization group treatment of a zero-temperature quantum-critical end-point. We summarize the results of mean field theory and give a pedagogical derivation of the renormalization-group equations. These are then solved to yield numerical results for the susceptibility, the specific heat and the resistivity exponent which can be compared with measured data on to provide a powerful test for the standard framework of metallic quantum criticality. The observed approach to the critical point is well-described by our theory explaining a number of unusual features of experimental data. The puzzling behaviour very near to the critical point itself, though, is not accounted for by this, or any other theory with a Fermi surface
Electronic structure investigation of CeB6 by means of soft X-ray scattering
The electronic structure of the heavy fermion compound CeB6 is probed by
resonant inelastic soft X-ray scattering using photon energies across the Ce 3d
and 4d absorption edges. The hybridization between the localized 4f orbitals
and the delocalized valence-band states is studied by identifying the different
spectral contributions from inelastic Raman scattering and normal fluorescence.
Pronounced energy-loss structures are observed below the elastic peak at both
the 3d and 4d thresholds. The origin and character of the inelastic scattering
structures are discussed in terms of charge-transfer excitations in connection
to the dipole allowed transitions with 4f character. Calculations within the
single impurity Anderson model with full multiplet effects are found to yield
consistent spectral functions to the experimental data.Comment: 9 pages, 4 figures, 1 table,
http://link.aps.org/doi/10.1103/PhysRevB.63.07510
Maternal autoimmunity and inflammation are associated with childhood tics and obsessive-compulsive disorder: Transcriptomic data show common enriched innate immune pathways.
Although genetic variation is a major risk factor of neurodevelopmental disorders, environmental factors during pregnancy and early life are also important in disease expression. Animal models demonstrate that maternal inflammation causes fetal neuroinflammation and neurodevelopmental deficits, and brain transcriptomics of neurodevelopmental disorders in humans show upregulated differentially expressed genes are enriched in immune pathways. We prospectively recruited 200 sequentially referred children with tic disorders/obsessive-compulsive disorder (OCD), 100 autoimmune neurological controls, and 100 age-matched healthy controls. A structured interview captured the maternal and family history of autoimmune disease and other pro-inflammatory states. Maternal blood and published Tourette brain transcriptomes were analysed for overlapping enriched pathways. Mothers of children with tics/OCD had a higher rate of autoimmune disease compared with mothers of children with autoimmune neurological conditions (p = 0.054), and mothers of healthy controls (p = 0.0004). Autoimmunity was similarly elevated in first- and second-degree maternal relatives of children with tics/OCD (p 0.0001 and p = 0.014 respectively). Other pro-inflammatory states were also more common in mothers of children with tics/OCD than controls (p 0.0001). Upregulated differentially expressed genes in maternal autoimmune disease and Tourette brain transcriptomes were commonly enriched in innate immune processes. Pro-inflammatory states, including autoimmune disease, are more common in the mothers and families of children with tics/OCD. Exploratory transcriptome analysis indicates innate immune signalling may link maternal inflammation and childhood tics/OCD. Targeting inflammation may represent preventative strategies in pregnancy and treatment opportunities for children with neurodevelopmental disorders
KCNT1- related epilepsy: An international multicenter cohort of 27 pediatric cases
ObjectiveThrough international collaboration, we evaluated the phenotypic aspects of a multiethnic cohort of KCNT1- related epilepsy and explored genotype- phenotype correlations associated with frequently encountered variants.MethodsA cross- sectional analysis of children harboring pathogenic or likely pathogenic KCNT1 variants was completed. Children with one of the two more common recurrent KCNT1 variants were compared with the rest of the cohort for the presence of particular characteristics.ResultsTwenty- seven children (15 males, mean age = 40.8 months) were included. Seizure onset ranged from 1 day to 6 months, and half (48.1%) exhibited developmental plateauing upon onset. Two- thirds had epilepsy of infancy with migrating focal seizures (EIMFS), and focal tonic seizures were common (48.1%). The most frequent recurrent KCNT1 variants were c.2800G>A; p.Ala934Thr (n = 5) and c.862G>A; p.Gly288Ser (n = 4). De novo variants were found in 96% of tested parents (23/24). Sixty percent had abnormal magnetic resonance imaging (MRI) findings. Delayed myelination, thin corpus callosum, and brain atrophy were the most common. One child had gray- white matter interface indistinctness, suggesting a malformation of cortical development. Several antiepileptic drugs (mean = 7.4/patient) were tried, with no consistent response to any one agent. Eleven tried quinidine; 45% had marked (>50% seizure reduction) or some improvement (25%- 50% seizure reduction). Seven used cannabidiol; 71% experienced marked or some improvement. Fourteen tried diet therapies; 57% had marked or some improvement. When comparing the recurrent variants to the rest of the cohort with respect to developmental trajectory, presence of EIMFS, >500 seizures/mo, abnormal MRI, and treatment response, there were no statistically significant differences. Four patients died (15%), none of sudden unexpected death in epilepsy.SignificanceOur cohort reinforces common aspects of this highly pleiotropic entity. EIMFS manifesting with refractory tonic seizures was the most common. Cannabidiol, diet therapy, and quinidine seem to offer the best chances of seizure reduction, although evidence- based practice is still unavailable.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154940/1/epi16480_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154940/2/epi16480.pd
Cavitating Leukoencephalopathy With Posterior Predominance Caused by a Deletion in the APOPT1 Gene in an Indian Boy
A 5-year-old Indian boy presented with subacute onset regression of milestones associated with seizures and spasticity. The symptoms started after an attack of measles. The magnetic resonance imaging (MRI) of the brain showed cavitating leukodystrophy with posterior predominance. Molecular analysis of the APOPT1 gene, a recently described gene associated with mitochondrial leukodystrophy, showed the patient to be homozygous for a 12.82-kilobase deletion, including coding exon 3. Deletion of exon 3 produces a frameshift, predicting the translation of a truncated protein (p.Glu121Valfs*4). The patient was started on mitochondrial cocktail regimen of thiamine, riboflavin, coenzyme Q and carnitine. Although he initially showed some improvement, he died 6 months after the onset of his illness