Medicine and Health Sciences Commons^™

Growth Hormone Deficiency In Megalencephaly-Capillary Malformation Syndrome: An Association With Activating Mutations In Pik3ca, Shanlee Davis, Meredith A Ware, Jordan Zeiger, Matthew A Deardorff, Katheryn Grand, Adda Grimberg, Stephanie Hsu, Megan Kelsey, Shideh Majidi, Revi P Matthew, Melanie Napier, Natalie Nokoff, Chitra Prasad, Andrew C Riggs, Margaret L Mckinnon, Ghayda Mirzaa

Paediatrics Publications

Megalencephaly-capillary malformation syndrome (MCAP) is a brain overgrowth disorder characterized by cortical malformations (specifically polymicrogyria), vascular anomalies, and segmental overgrowth secondary to somatic activating mutations in the PI3K-AKT-MTOR pathway (PIK3CA). Cases of growth failure and hypoglycemia have been reported in patients with MCAP, raising the suspicion for unappreciated growth hormone (GH) deficiency. Here we report an observational multicenter study of children with MCAP and GH deficiency. Eleven participants were confirmed to have GH deficiency, all with very low or undetectable circulating concentrations of insulin-like growth factor-1 and insulin-like growth factor binding protein-3. Seven underwent GH stimulation testing and all had …

Linked Mri Signatures Of The Brain's Acute And Persistent Response To Concussion In Female Varsity Rugby Players., Kathryn Y Manning, Alberto Llera, Gregory A Dekaban, Robert Bartha, Christy Barreira, Arthur Brown, Lisa Fischer, Tatiana Jevremovic, Kevin Blackney, Timothy J Doherty, Douglas D Fraser, Jeff Holmes, Christian F Beckmann, Ravi S Menon

Paediatrics Publications

Acute brain changes are expected after concussion, yet there is growing evidence of persistent abnormalities well beyond clinical recovery and clearance to return to play. Multiparametric MRI is a powerful approach to non-invasively study structure-function relationships in the brain, however it remains challenging to interpret the complex and heterogeneous cascade of brain changes that manifest after concussion. Emerging conjunctive, data-driven analysis approaches like linked independent component analysis can integrate structural and functional imaging data to produce linked components that describe the shared inter-subject variance across images. These linked components not only offer the potential of a more comprehensive understanding of …

Magnetic Resonance Imaging In The Diagnosis Of White Matter Signal Abnormalities., Ravi Datar, Asuri Narayan Prasad, Keng Yeow Tay, Charles Anthony Rupar, Pavlo Ohorodnyk, Michael Miller, Chitra Prasad

Paediatrics Publications

Background White matter abnormalities (WMAs) pose a diagnostic challenge when trying to establish etiologic diagnoses. During childhood and adult years, genetic disorders, metabolic disorders and acquired conditions are included in differential diagnoses. To assist clinicians and radiologists, a structured algorithm using cranial magnetic resonance imaging (MRI) has been recommended to aid in establishing working diagnoses that facilitate appropriate biochemical and genetic investigations. This retrospective pilot study investigated the validity and diagnostic utility of this algorithm when applied to white matter signal abnormalities (WMSAs) reported on imaging studies of patients seen in our clinics. Methods The MRI algorithm was applied to …

Disruption To Functional Networks In Neonates With Perinatal Brain Injury Predicts Motor Skills At 8 Months, Annika C Linke, Conor Wild, Leire Zubiaurre-Elorza, Charlotte Herzmann, Hester Duffy, Victor K Han, David S C Lee, Rhodri Cusack

Paediatrics Publications

Objective

Functional connectivity magnetic resonance imaging (fcMRI) of neonates with perinatal brain injury could improve prediction of motor impairment before symptoms manifest, and establish how early brain organization relates to subsequent development. This cohort study is the first to describe and quantitatively assess functional brain networks and their relation to later motor skills in neonates with a diverse range of perinatal brain injuries.

Methods

Infants (n = 65, included in final analyses: n = 53) were recruited from the neonatal intensive care unit (NICU) and were stratified based on their age at birth (prematurevs. term), and on whether neuropathology …

Identification Of A Novel Synaptic Protein, Tmtc3, Involved In Periventricular Nodular Heterotopia With Intellectual Disability And Epilepsy, Sali M K Farhan, Kevin C J Nixon, Michelle Everest, Tara N Edwards, Shirley Long, Dmitri Segal, Maria J Knip, Heleen H Arts, Rana Chakrabarti, Jian Wang, John F Robinson, Donald Lee, Seyed M Mirsattari, C Anthony Rupar, Victoria M Siu, Forge Canada Consortium, Michael O Poulter, Robert A Hegele, Jamie M Kramer

Paediatrics Publications

Defects in neuronal migration cause brain malformations, which are associated with intellectual disability (ID) and epilepsy. Using exome sequencing, we identified compound heterozygous variants (p.Arg71His and p. Leu729ThrfsTer6) in TMTC3, encoding transmembrane and tetratricopeptide repeat containing 3, in four siblings with nocturnal seizures and ID. Three of the four siblings have periventricular nodular heterotopia (PVNH), a common brain malformation caused by failure of neurons to migrate from the ventricular zone to the cortex. Expression analysis using patient-derived cells confirmed reduced TMTC3 transcript levels and loss of the TMTC3 protein compared to parental and control cells. As TMTC3 function is currently …

Heterozygous De Novo Ubtf Gain-Of-Function Variant Is Associated With Neurodegeneration In Childhood., Simon Edvardson, Claudia M Nicolae, Pankaj B Agrawal, Cyril Mignot, Katelyn Payne, Asuri Narayan Prasad, Chitra Prasad, Laurie Sadler, Caroline Nava, Thomas E Mullen, Amber Begtrup, Berivan Baskin, Zöe Powis, Avraham Shaag, Boris Keren, George-Lucian Moldovan, Orly Elpeleg

Paediatrics Publications

Ribosomal RNA (rRNA) is transcribed from rDNA by RNA polymerase I (Pol I) to produce the 45S precursor of the 28S, 5.8S, and 18S rRNA components of the ribosome. Two transcription factors have been defined for Pol I in mammals, the selectivity factor SL1, and the upstream binding transcription factor (UBF), which interacts with the upstream control element to facilitate the assembly of the transcription initiation complex including SL1 and Pol I. In seven unrelated affected individuals, all suffering from developmental regression starting at 2.5-7 years, we identified a heterozygous variant, c.628G>A in UBTF, encoding p.Glu210Lys in UBF, which …

Mosaic Expression Of Atrx In The Mouse Central Nervous System Causes Memory Deficits, Renee J Tamming, Jennifer R Siu, Yan Jiang, Marco A M Prado, Frank Beier, Nathalie G Bérubé

Paediatrics Publications

The rapid modulation of chromatin organization is thought to play a crucial role in cognitive processes such as memory consolidation. This is supported in part by the dysregulation of many chromatin-remodelling proteins in neurodevelopmental and psychiatric disorders. A key example is ATRX, an X-linked gene commonly mutated in individuals with syndromic and nonsyndromic intellectual disability. The consequences of Atrx inactivation for learning and memory have been difficult to evaluate because of the early lethality of hemizygous-null animals. In this study, we evaluated the outcome of brain-specific Atrx deletion in heterozygous female mice. These mice exhibit a mosaic pattern of ATRX …

Analysis Of Neonatal Brain Lacking Atrx Or Mecp2 Reveals Changes In Nucleosome Density, Ctcf Binding And Chromatin Looping, Kristin D Kernohan, Douglas Vernimmen, Gregory B Gloor, Nathalie G. Bérubé

Paediatrics Publications

ATRX and MeCP2 belong to an expanding group of chromatin-associated proteins implicated in human neurodevelopmental disorders, although their gene-regulatory activities are not fully resolved. Loss of ATRX prevents full repression of an imprinted gene network in the postnatal brain and in this study we address the mechanistic aspects of this regulation. We show that ATRX binds many imprinted domains individually but that transient co-localization between imprinted domains in the nuclei of neurons does not require ATRX. We demonstrate that MeCP2 is required for ATRX recruitment and that deficiency of either ATRX or MeCP2 causes decreased frequency of long-range chromatin interactions …

Localization Of Pain-Related Brain Activation: A Meta-Analysis Of Neuroimaging Data, Emma G. Duerden, Marie Claire Albanese

Paediatrics Publications

A meta-analysis of 140 neuroimaging studies was performed using the activation-likelihood-estimate (ALE) method to explore the location and extent of activation in the brain in response to noxious stimuli in healthy volunteers. The first analysis involved the creation of a likelihood map illustrating brain activation common across studies using noxious stimuli. The left thalamus, right anterior cingulate cortex (ACC), bilateral anterior insulae, and left dorsal posterior insula had the highest likelihood of being activated. The second analysis contrasted noxious cold with noxious heat stimulation and revealed higher likelihood of activation to noxious cold in the subgenual ACC and the amygdala. …