DIAPH1-Deficiency is Associated with Major T, NK and ILC Defects in Humans.

Loss of function mutations in Diaphanous related formin 1 (DIAPH1) are associated with seizures, cortical blindness, and microcephaly syndrome (SCBMS) and are recently linked to combined immunodeficiency. However, the extent of defects in T and innate lymphoid cells (ILCs) remain unexplored. Herein, we characterized the primary T, natural killer (NK) and helper ILCs of six patients carrying two novel loss of function mutation in DIAPH1 and Jurkat cells after DIAPH1 knockdown. Mutations were identified by whole exome sequencing. T-cell immunophenotyping, proliferation, migration, cytokine signaling, survival, and NK cell cytotoxicity were studied via flow cytometry-based assays, confocal microscopy, and real-time qPCR. CD4+ T cell proteome was analyzed by mass spectrometry. p.R351* and p.R322*variants led to a significant reduction in the DIAPH1 mRNA and protein levels. DIAPH1-deficient T cells showed proliferation, activation, as well as TCR-mediated signaling defects. DIAPH1-deficient PBMCs also displayed impaired transwell migration, defective STAT5 phosphorylation in response to IL-2, IL-7 and IL-15. In vitro generation/expansion of Treg cells from naïve T cells was significantly reduced. shRNA-mediated silencing of DIAPH1 in Jurkat cells reduced DIAPH1 protein level and inhibited T cell proliferation and IL-2/STAT5 axis. Additionally, NK cells from patients had diminished cytotoxic activity, function and IL-2/STAT5 axis. Lastly, DIAPH1-deficient patients' peripheral blood contained dramatically reduced numbers of all helper ILC subsets. DIAPH1 deficiency results in major functional defects in T, NK cells and helper ILCs underlining the critical role of formin DIAPH1 in the biology of those cell subsets.

Diffusion-weighted imaging in Sydenham's chorea.

PURPOSE: The purpose of this study was to determine of caudate nucleus changes in diffusion-weighted magnetic resonance imaging. METHODS: A total of 13 children (four males and nine females) with history of Sydenham's chorea and 13 healthy controls were included in to the study. Diffusion cranial magnetic resonance imaging was performed in all subjects before prednisone treatment. Prednisone (2 mg/kg/day, maximum dose 60 mg/day) was used during 4 weeks and then progressively discontinued (20 % of the initial dose was reduced at each 5 days). Two months later, magnetic resonance imaging was repeated. RESULTS: Before and after 8 weeks of prednisone treatment, apparent diffusion coefficients (ADCs) were calculated for right and left caudate nucleus. The ADC values were significantly different before treatment and 2 months after imaging. For the left caudate nucleus, ADC values before treatment (0.69 ± 0.038) were significantly lower than after treatment (0.95 ± 0.04). For the right caudate nucleus, ADC values before treatment (0.72 ± 0.06 × 10(-3)) were significantly lower than after treatment (0.93 ± 0.04 × 10(-3)). CONCLUSIONS: Although cranial and caudate nucleus magnetic resonance imaging findings were normal, the low ADC value findings in our study support the autoimmune inflammation in basal ganglia of Sydenham's chorea.

Clinical and genetic studies of thiamine metabolism dysfunction syndrome-4: case series and review of the literature.

Thiamine metabolism dysfunction syndrome-4 (THMD-4) is an autosomal recessive inherited rare disease (OMIM #613710) characterized by febrile illness associated episodic encephalopathy, leading to transient neurological dysfunction and progressive polyneuropathy. We report three patients from two different families with normal development, episodic encephalopathy, gait disorder, progressive chronic polyneuropathy characterized by motor difficulties, distal weakness, and hoarseness (dysphonia). We identified a homozygous missense c.576G>C, p.(Gln192His) variant in the SLC25A19 gene in both families by whole-exome sequencing. Following genetic diagnosis, thiamine replacement therapy was started, and improvement was observed in all affected patients. We highlight the associated phenotypes of an SCL25A19 mutation leading to clinical features of THMD-4.