The expanding clinical and genetic spectrum of DYNC1H1-related disorders.

Intracellular trafficking involves an intricate machinery of motor complexes including the dynein complex to shuttle cargo for autophagolysosomal degradation. Deficiency in dynein axonemal chains as well as cytoplasmic light and intermediate chains have been linked with ciliary dyskinesia and skeletal dysplasia. The cytoplasmic dynein 1 heavy chain protein (DYNC1H1) serves as a core complex for retrograde trafficking in neuronal axons. Dominant pathogenic variants in DYNC1H1 have been previously implicated in peripheral neuromuscular disorders (NMD) and neurodevelopmental disorders (NDD). As heavy-chain dynein is ubiquitously expressed, the apparent selectivity of heavy-chain dyneinopathy for motor neuronal phenotypes remains currently unaccounted for. Here, we aimed to evaluate the full DYNC1H1-related clinical, molecular and imaging spectrum, including multisystem features and novel phenotypes presenting throughout life. We identified 47 cases from 43 families with pathogenic heterozygous variants in DYNC1H1 (aged 0-59 years) and collected phenotypic data via a comprehensive standardized survey and clinical follow-up appointments. Most patients presented with divergent and previously unrecognized neurological and multisystem features, leading to significant delays in genetic testing and establishing the correct diagnosis. Neurological phenotypes include novel autonomic features, previously rarely described behavioral disorders, movement disorders, and periventricular lesions. Sensory neuropathy was identified in nine patients (median age of onset 10.6 years), of which five were only diagnosed after the second decade of life, and three had a progressive age-dependent sensory neuropathy. Novel multisystem features included primary immunodeficiency, bilateral sensorineural hearing loss, organ anomalies, and skeletal manifestations, resembling the phenotypic spectrum of other dyneinopathies. We also identified an age-dependent biphasic disease course with developmental regression in the first decade and, following a period of stability, neurodegenerative progression after the second decade of life. Of note, we observed several cases in whom neurodegeneration appeared to be prompted by intercurrent systemic infections with double-stranded DNA viruses (Herpesviridae) or single-stranded RNA viruses (Ross-River fever, SARS-CoV-2). Moreover, the disease course appeared to be exacerbated by viral infections regardless of age and/or severity of NDD manifestations, indicating a role of dynein in anti-viral immunity and neuronal health. In summary, our findings expand the clinical, imaging, and molecular spectrum of pathogenic DYNC1H1 variants beyond motor neuropathy disorders and suggest a life-long continuum and age-related progression due to deficient intracellular trafficking. This study will facilitate early diagnosis and improve counselling and health surveillance of affected patients.

A 5-year-old boy with super-refractory status epilepticus and RANBP2 variant warranting life-saving hemispherotomy.

Focal cortical dysplasia (FCD) represents the most common cause of drug-resistant epilepsy in adult and pediatric surgical series. However, genetic factors contributing to severe phenotypes of FCD remain unknown. We present a patient with an exceptionally rapid development of drug-resistant epilepsy evolving in super-refractory status epilepticus. We performed multiple clinical (serial EEG, MRI), biochemical (metabolic and immunological screening), genetic (WES from blood- and brain-derived DNA), and histopathological investigations. The patient presented 1 month after an uncomplicated varicella infection. MRI was negative, as well as other biochemical and immunological examinations. Whole-exome sequencing of blood-derived DNA detected a heterozygous paternally inherited variant NM_006267.4(RANBP2):c.5233A>G p.(Ile1745Val) (Chr2[GRCh37]:g.109382228A>G), a gene associated with a susceptibility to infection-induced acute necrotizing encephalopathy. No combination of anti-seizure medication led to a sustained seizure freedom and the patient warranted induction of propofol anesthesia with high-dose intravenous midazolam and continuous respiratory support that however failed to abort seizure activity. Brain biopsy revealed FCD type IIa; this finding led to the indication of an emergency right-sided hemispherotomy that rendered the patient temporarily seizure-free. Postsurgically, he remains on antiseizure medication and experiences rare nondisabling seizures. This report highlights a uniquely severe clinical course of FCD putatively modified by the RANBP2 variant. PLAIN LANGUAGE SUMMARY: We report a case summary of a patient who came to our attention for epilepsy that could not be controlled with medication. His clinical course progressed rapidly to life-threatening status epilepticus with other unusual neurological findings. Therefore, we decided to surgically remove a piece of brain tissue in order to clarify the diagnosis that showed features of a structural brain abnormality associated with severe epilepsy, the focal cortical dysplasia. Later, a genetic variant in a gene associated with another condition, was found, and we hypothesize that this genetic variant could have contributed to this severe clinical course of our patient.

Neurodevelopmental and Epilepsy Phenotypes in Individuals With Missense Variants in the Voltage-Sensing and Pore Domains of KCNH5.

BACKGROUND AND OBJECTIVES: KCNH5 encodes the voltage-gated potassium channel EAG2/Kv10.2. We aimed to delineate the neurodevelopmental and epilepsy phenotypic spectrum associated with de novo KCNH5 variants. METHODS: We screened 893 individuals with developmental and epileptic encephalopathies for KCNH5 variants using targeted or exome sequencing. Additional individuals with KCNH5 variants were identified through an international collaboration. Clinical history, EEG, and imaging data were analyzed; seizure types and epilepsy syndromes were classified. We included 3 previously published individuals including additional phenotypic details. RESULTS: We report a cohort of 17 patients, including 9 with a recurrent de novo missense variant p.Arg327His, 4 with a recurrent missense variant p.Arg333His, and 4 additional novel missense variants. All variants were located in or near the functionally critical voltage-sensing or pore domains, absent in the general population, and classified as pathogenic or likely pathogenic using the American College of Medical Genetics and Genomics criteria. All individuals presented with epilepsy with a median seizure onset at 6 months. They had a wide range of seizure types, including focal and generalized seizures. Cognitive outcomes ranged from normal intellect to profound impairment. Individuals with the recurrent p.Arg333His variant had a self-limited drug-responsive focal or generalized epilepsy and normal intellect, whereas the recurrent p.Arg327His variant was associated with infantile-onset DEE. Two individuals with variants in the pore domain were more severely affected, with a neonatal-onset movement disorder, early-infantile DEE, profound disability, and childhood death. DISCUSSION: We describe a cohort of 17 individuals with pathogenic or likely pathogenic missense variants in the voltage-sensing and pore domains of Kv10.2, including 14 previously unreported individuals. We present evidence for a putative emerging genotype-phenotype correlation with a spectrum of epilepsy and cognitive outcomes. Overall, we expand the role of EAG proteins in human disease and establish KCNH5 as implicated in a spectrum of neurodevelopmental disorders and epilepsy.

Influence of in vitro IL-2 or IL-15 alone or in combination with Hsp-70-derived 14-mer peptide (TKD) on the expression of NK cell activatory and inhibitory receptors.

NK cells represent a potential tool for adoptive immunotherapy against tumors. Membrane-bound Hsp70 acts as a tumor-specific marker enhancing NK cell activity. Using flow cytometry the effect of in vitro stimulation with IL-2 or IL-15 alone or in combination with Hsp70-derived 14-mer peptide (TKD) on cell surface expression of NK activatory receptors (CD16, NKG2D, NKG2C, NKp46, NKp44, NKp30, KIR2DL4, DNAM-1, and LAMP1) and NK inhibitory receptors (NKG2A, KIR2DL2/L3, LIR1/ILT-2, and NKR-P1A) in healthy individuals was studied. Results were expressed as the percentage of receptor expressing cells and the amount of receptor expressed by CD3(-)CD56(+) cellular population. CD94, NKG2D, NKp44, NKp30, KIR2DL4, DNAM-1, LAMP1, NKG2A, and NKR-P1A were upregulated after the stimulation with IL-2 or IL-15 alone or in combination with TKD. KIR2DL2/L3 was upregulated only by IL-15 and IL-15/TKD. Concurrently, an increase in a number of NK cells positive for CD94, NKp44, NKp30, KIR2DL4, and LAMP1 was observed. IL-15 and IL-15/TKD caused also cell number rise positive for KIR2DL2/L3 and NKR-P1A. Cell number positive for NKG2C and NKG2A was increased only by IL-2 and IL-2/TKD. The diverse effect of IL-2 or IL-15 w or w/o TKD on cell surface expression was observed in CD16, NKp46, and LIR1/ILT-2.

Heat-shock protein expression in leukemia.

Heat-shock proteins (Hsps) are thought to play a role in the development of cancer and to modulate tumor response to cytotoxic therapy. In this study, Hsp27, Hsp60, Hsp90α, and HspBP1 gene expression was investigated in human leukemia cell lines as well as in leukemia cells derived from patients with the onset of the disease. Hsp70 membrane expression and expression of Hsp27, Hsp60, Hsp70, Hsp90α, and HspBP1 genes were also tested in samples from leukemia patients. Relative Hsps gene expression was examined in human leukemia cell lines and also in patients, using real-time quantitative reverse-transcriptase polymerase chain reaction (RT-PCR). Hsp70 cell surface expression was studied in patients with leukemia onset using flow cytometry. All tested cell lines showed significantly increased expression of Hsp60, Hsp90α, and HspBP1 genes compared with a cohort of healthy controls; additionally there was increased Hsp27 expression except for Jurkat and CCRF cells. Significantly higher gene expression of Hsp27, Hsp60, Hsp90α, and HspBP1 was observed in the peripheral blood of patients compared with bone marrow and healthy control samples, while Hsp70 expression was without any significant difference among cohorts. Hsp70 cell surface expression was found on defrosted and cultured leukemia cells but not on unprocessed biological samples from patients. Leukemia cells showed a heterogeneous pattern of Hsp gene expression among leukemia cell lines as well as in peripheral blood and bone marrow of patients.

Expression of heat shock protein 70 and NKG2D ligands in acute myeloid leukemia cell lines.

UNLABELLED: Membrane-bound heat shock protein 70 (HSP70) was found to be tumor-specific and was proposed as a target for immunotherapy. In the present study, we analyzed cell surface and relative gene expression of HSP70 in cell lines established from patients with different acute myeloid leukemia (AML) subtypes, together with the expression of natural killer (NK) cell activation/inhibitory ligands. MATERIALS AND METHODS: Six AML cell lines were included in this study. The relative gene expression of HSP70 was analyzed using the real-time reverse-transcriptase polymerase chain reaction. Surface expression of HSP70 and NK cell ligands was analyzed using flow cytometry. RESULTS: All cell lines overexpressed HSP70; however, its mRNA levels were not elevated. The expression of NKG2D activation ligands was heterogeneous. CONCLUSION: Our study is the first to describe long-term stationary cell surface expression of HSP70 in different subtypes of AML. Combined with the results of the gene expression experiments these data provide more evidence to the idea of a self-limiting mechanism for HSP70 expression.

Analysis of cell surface and relative gene expression of heat shock protein 70 in human leukemia cell lines.

Hsp70 was found to be expressed on the cell surface of leukemia cell lines compared with normal cells. Hsp70 cell surface and mRNA expression was studied in K562, Jurkat and CCRF-CEM human leukemia cell lines during several passages of in vitro culture. All the cell lines were positive for cell surface Hsp70 expression. However, increased mRNA expression was observed only in K562 cells where the expression was 9.88-fold higher on average compared with healthy controls. Jurkat cells, however, showed a significant negative correlation between cell surface and mRNA Hsp70 expression; high cell surface expression correlated with low mRNA expression in the Jurkat cell line.

Peripheral blood mononuclear cell responses to heat shock proteins in patients undergoing stem cell transplantation.

GVHD is a major complication after allogeneic SCT. Etiology of GVHD is multifactorial. Known role of hSPS in antigen presentation could suggest their potential role in the alloreactive process that leads to aGVHD. HSPS represent major immunodominant antigens in a wide spectrum of microbial pathogens. Bacterial and fungal colonization, infection and sepsis are frequent in immunocompromised patients with various malignant and non-malignant diseases. We studied PBMC responses to recombinant human hsp60 (rh-hsp60), rh-hsp70 and Mycobacterium bovis hsp65 (M. bovis hsp65) in relation to aGVHD and infection in 34 pediatric patients with various lympho-hemopoietic malignancies as well as non-malignant disorders subjected to SCT. PBMC of patients before initiation of preparative regimen as well as after engraftment were stimulated with hSPS (1 microg/mL/well, 7-day cultivation). PHA was used as a control of the stimulation ability. Cell responses were measured after the incorporation of 3H-thymidin (pulsing with 1 microCi/well) and were expressed as stimulation indexes (SI). We demonstrated significantly high proliferative response to rh-hsp60 as well as M. bovis hsp65 in a cohort of pretransplant patients with anamnestic and/or actual infection when compared with a cohort of patients without infection and healthy individuals. Strong PBMC cell responses to hSPS were found in patients who were at present colonized with Escherichia coli and Klebsiella pneumoniae or had previously K. pneumoniae infection with subsequent sepsis. Our findings support various studies dealing with immunodominant hSPS in connection with several pathogens and infectious diseases. Although no statistical difference for proliferative response to PHA was observed, PBMC responses against all tested hSPS comparing a cohort of patients with aGVHD and that with no sign of GVHD resulted in significantly lower SI for all tested hSPS in patients with aGVHD. Lower stimulation with hSPS during aGVHD might be explained by the stress-induced upregulation of self-hSPS synthesis that might lead to the inhibition of self-hSPS reactive T-cell response. Vice versa, we hypothesize that increased hsp-specific stimulation may reflect the presence of protecting regulatory T cells preventing the development of Th1-mediated diseases involving aGVHD.