Publications by authors named "Shashi"

Article Synopsis
  • - The study evaluated the efficacy of telehealth in conducting physical examinations (PE) for individuals with undiagnosed and rare disorders, comparing virtual assessments to in-person examinations.
  • - Results showed high agreement in general appearance and craniofacial features between telehealth and in-person evaluations, with varying levels of agreement for neurological examination components.
  • - Participants reported satisfaction with the telehealth experience, indicating that telehealth is a viable alternative for conducting physical examinations in cases of undiagnosed diseases.
View Article and Find Full Text PDF

The heterotrimeric protein phosphatase 2A (PP2A) complex catalyzes about half of Ser/Thr dephosphorylations in eukaryotic cells. A CAG repeat expansion in the neuron-specific protein PP2A regulatory subunit PPP2R2B gene causes spinocerebellar ataxia type 12 (SCA12). We established five monoallelic missense variants in PPP2R2B (four confirmed as de novo) as a cause of intellectual disability with developmental delay (R149P, T246K, N310K, E37K, I427T).

View Article and Find Full Text PDF

The maintenance of lipid asymmetry on the plasma membrane is regulated by flippases, such as ATP8A2, ATP11A, and ATP11C, which translocate phosphatidylserine and phosphatidylethanolamine from the outer leaflet to the inner leaflet. We previously identified a patient-derived point mutation (Q84E) in ATP11A at the phospholipid entry site, which acquired the ability to flip phosphatidylcholine (PtdCho). This mutation led to elevated levels of sphingomyelin (SM) in the outer leaflet of the plasma membrane.

View Article and Find Full Text PDF
Article Synopsis
  • APECED is a serious genetic autoimmune disorder linked to variants in the autoimmune regulator (AIRE) gene, with 16% of evaluated patients lacking known harmful variants, most of whom are of Puerto Rican descent.
  • Researchers discovered a deep intronic variant (c.1504-818 G>A) in these patients that causes a cryptic splice site leading to a dysfunctional protein through pseudoexon inclusion.
  • They developed an antisense oligonucleotide (ASO) that corrected this genetic issue, demonstrating the potential for targeted treatments in APECED patients.
View Article and Find Full Text PDF

Members of the leucine rich repeat (LRR) and PDZ domain (LAP) protein family are essential for animal development and histogenesis. Densin-180, encoded by LRRC7, is the only LAP protein selectively expressed in neurons. Densin-180 is a postsynaptic scaffold at glutamatergic synapses, linking cytoskeletal elements with signalling proteins such as the α-subunit of Ca/calmodulin-dependent protein kinase II.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the effectiveness and safety of cryoablation for treating desmoid tumors in pediatric and young adult patients over a 10-year period.
  • A total of 21 patients underwent 34 cryoablation procedures, with significant pain relief and improved mobility reported; 90% of patients showed symptom improvement.
  • Most tumors showed at least partial volume reduction, with some achieving complete response, and only a few minor complications were noted, indicating cryoablation is a promising treatment option.
View Article and Find Full Text PDF

Developmental and epileptic encephalopathies (DEEs) feature altered brain development, developmental delay and seizures, with seizures exacerbating developmental delay. Here we identify a cohort with biallelic variants in DENND5A, encoding a membrane trafficking protein, and develop animal models with phenotypes like the human syndrome. We demonstrate that DENND5A interacts with Pals1/MUPP1, components of the Crumbs apical polarity complex required for symmetrical division of neural progenitor cells.

View Article and Find Full Text PDF

The eye is a most delicate organ protected by several complex biological barriers that are static and dynamic. The presence of these ocular barriers retards drug absorption from topically applied dosage forms at the conjunctival sac. The efficient topical delivery of the drug into the globe is more difficult to achieve and there is a need to develop a topical formulation that may reduce the use of injections and increase patient compliance with decreased frequency of administration.

View Article and Find Full Text PDF
Article Synopsis
  • Zinner Syndrome (ZS) is a rare congenital condition combining seminal vesicle cysts with urinary tract abnormalities, usually asymptomatic in childhood and presenting later with various symptoms.
  • A 22-year study identified 20 pediatric cases, analyzing demographics, symptoms, and imaging results which showed renal and seminal vesicle abnormalities, with surgical treatments performed for symptomatic patients.
  • Early diagnosis is critical, often requiring advanced imaging and a multidisciplinary approach for effective management of ZS, particularly for symptomatic cases that may benefit from surgery.
View Article and Find Full Text PDF

Although next-generation sequencing has enabled diagnoses for many patients with Mendelian disorders, the majority remain undiagnosed. Here, we present a sibling pair who were clinically diagnosed with Escobar syndrome, however targeted gene testing was negative. Exome sequencing (ES), and later genome sequencing (GS), revealed compound heterozygous TTN variants in both siblings, a maternally inherited frameshift variant [(NM_133378.

View Article and Find Full Text PDF
Article Synopsis
  • * A study identified 25 individuals with new variations in the MSL2 gene, who exhibited NDD symptoms such as developmental delays, coordination problems, and autism spectrum disorder, along with other health concerns.
  • * iPSCs from affected individuals showed reduced MSL2 levels and changes in gene expression, leading to the characterization of a new MSL2-related disorder with unique clinical markers and a specific DNA episignature for diagnosis.
View Article and Find Full Text PDF
Article Synopsis
  • HCN gated channels play a vital role in brain functions like learning and sensory processing, and their dysfunction is linked to brain disorders, particularly epilepsy.
  • The study identifies 21 individuals with genetic variations associated with developmental delays, intellectual disabilities, and epilepsy, expanding our understanding of related disorders.
  • Functional tests on specific variants revealed that some mutations significantly increased HCN2 channel conductance, while others caused loss of function and impaired channel trafficking, suggesting diverse impacts of these variants on brain function.
View Article and Find Full Text PDF

Ultra rare disorders are being diagnosed at an unprecedented rate, due to genomic sequencing. These diagnoses are often a new gene association, for which little is known, and few share the diagnosis. For these diagnoses, we use the term emerging-ultrarare disorder (E-URD), defined as <100 diagnosed individuals.

View Article and Find Full Text PDF
Article Synopsis
  • * The study focuses on 48 de novo missense variants in GRIN1, GRIN2A, and GRIN2B that affect the M3 transmembrane helix, identified in children with conditions like epilepsy and developmental delays.
  • * Most of these variants lead to a gain-of-function effect, promoting NMDAR channel activity, reinforcing the importance of the M3 region in receptor function, and providing insights into how certain drugs may affect these variant receptors.
View Article and Find Full Text PDF

Biallelic pathogenic variants in CDC45 are associated with Meier-Gorlin syndrome with craniosynostosis (MGORS type 7), which also includes short stature and absent/hypoplastic patellae. Identified variants act through a hypomorphic loss of function mechanism, to reduce CDC45 activity and impact DNA replication initiation. In addition to missense and premature termination variants, several pathogenic synonymous variants have been identified, most of which cause increased exon skipping of exon 4, which encodes an essential part of the RecJ-orthologue's DHH domain.

View Article and Find Full Text PDF

Developmental and epileptic encephalopathies (DEEs) are a heterogenous group of epilepsies in which altered brain development leads to developmental delay and seizures, with the epileptic activity further negatively impacting neurodevelopment. Identifying the underlying cause of DEEs is essential for progress toward precision therapies. Here we describe a group of individuals with biallelic variants in and determine that variant type is correlated with disease severity.

View Article and Find Full Text PDF

The species diversity of freshwater crabs of Bangladesh is poorly known. In this study, (Alcock, 1909) and (Alcock, 1909) are reported as new records from Bangladesh. The two species were identified through morphology and molecular phylogeny based on 16S rDNA gene sequences.

View Article and Find Full Text PDF

Primary pediatric lung tumors are uncommon and have many overlapping clinical and imaging features. In contrast to adult lung tumors, these rare pediatric neoplasms have a relatively broad histologic spectrum. Informed by a single-institution 13-year retrospective record review, we present an overview of the most common primary pediatric lung neoplasms, with a focus on the role of positron emission tomography (PET), specifically F-fluorodeoxyglucose (FDG) PET and Ga-DOTATATE PET, in the management of primary pediatric lung tumors.

View Article and Find Full Text PDF

Objectives: To determine the added diagnostic value of contrast-enhanced ultrasound (CEUS) in pediatric chest abnormalities by comparing interpretation of CEUS studies and confidence level to conventional US studies.

Methods: CEUS studies in patients with a variety of clinically suspected chest abnormalities performed between 2016 and 2020 were reviewed and compared to same-day conventional US studies. Examinations were independently interpreted by 4 radiologists blinded to clinical and other imaging data.

View Article and Find Full Text PDF