A single-cell atlas of immunocytes in the spleen of a mouse model of Wiskott-Aldrich syndrome.

Wiskott-Aldrich syndrome (WAS) is a disorder characterized by rare X-linked genetic immune deficiency with mutations in the Was gene, which is specifically expressed in hematopoietic cells. The spleen plays a major role in hematopoiesis and red blood cell clearance. However, to date, comprehensive analyses of the spleen in wild-type (WT) and WASp-deficient (WAS-KO) mice, especially at the transcriptome level, have not been reported. In this study, single-cell RNA sequencing (scRNA-seq) was adopted to identify various types of immune cells and investigate the mechanisms underlying immune deficiency. We identified 30 clusters and 10 major cell subtypes among 11,269 cells; these cell types included B cells, T cells, dendritic cells (DCs), natural killer (NK) cells, monocytes, macrophages, granulocytes, stem cells and erythrocytes. Moreover, we evaluated gene expression differences among cell subtypes, identified differentially expressed genes (DEGs), and performed enrichment analyses to identify the reasons for the dysfunction in these different cell populations in WAS. Furthermore, some key genes were identified based on a comparison of the DEGs in each cell type involved in specific and nonspecific immune responses, and further analysis showed that these key genes were previously undiscovered pathology-related genes in WAS-KO mice. In summary, we present a landscape of immune cells in the spleen of WAS-KO mice based on detailed data obtained at single-cell resolution. These unprecedented data revealed the transcriptional characteristics of specific and nonspecific immune cells, and the key genes were identified, laying a foundation for future studies of WAS, especially studies into novel and underexplored mechanisms that may improve gene therapies for WAS.

Two patients with ZAP-70 deficiency in China present with a different genetic, immunological, and clinical phenotype.

Zeta(ζ)-Chain Associated Protein Kinase 70 kDa (ZAP-70) deficiency is a rare autosomal recessive primary immunodeficiency disease. Little is known about this disease. In this study, we report two patients to extend the range of clinical phenotypes and immunophenotypes associated with ZAP-70 mutations. We describe the clinical, genetic, and immunological phenotypes of two patients with ZAP-70 deficiency in China, and the data are also compared with the literature. Case 1 presented with leaky severe combined immunodeficiency with low to the absence of CD8 + T cells, while case 2 suffered from a recurrent respiratory infection and had a past medical history of non-EBV-associated Hodgkin's lymphoma. Sequencing revealed novel compound heterozygous mutations in ZAP-70 of these patients. Case 2 is the second ZAP-70 patient presenting a normal CD8 + T cell number. These two cases have been treated with hematopoietic stem cell transplantation. Selective CD8 + T cell loss is an essential feature of the immunophenotype of ZAP-70 deficiency patients, but there are exceptions. Hematopoietic stem cell transplantation can provide excellent long-term immune function and resolution of clinical problems.

Characterization of a Cohort of Patients With LIG4 Deficiency Reveals the Founder Effect of p.R278L, Unique to the Chinese Population.

DNA ligase IV (LIG4) deficiency is an extremely rare autosomal recessive primary immunodeficiency disease caused by mutations in LIG4. Patients suffer from a broad spectrum of clinical problems, including microcephaly, growth retardation, developmental delay, dysmorphic facial features, combined immunodeficiency, and a predisposition to autoimmune diseases and malignancy. In this study, the clinical, molecular, and immunological characteristics of 15 Chinese patients with LIG4 deficiency are summarized in detail. p.R278L (c.833G>T) is a unique mutation site present in the majority of Chinese cases. We conducted pedigree and haplotype analyses to examine the founder effect of this mutation site in China. This suggests that implementation of protocols for genetic diagnosis and for genetic counseling of affected pedigrees is essential. Also, the search might help determine the migration pathways of populations with Asian ancestry.

[Clinical features and genetic analysis of a child with mosaic variegated aneuploidy syndrome].

OBJECTIVE: To explore the clinical phenotype, genetic variant, treatment and prognosis of a child with mosaic variegated aneuploidy syndrome (MVAS). METHODS: Immunological marker screening, chromosomal karyotyping and whole exome sequencing were carried out. RESULTS: The 1-year-11-month old girl has featured severe growth retardation, feeding difficulty, short stature, microcephaly, facial anomalies, scoliosis, visual impairment, hypotonia, chylothorax, and renal lesions. Karyotype analysis of peripheral blood lymphocytes has discovered variegated aneuploidy cells (6/11). DNA sequencing has identified compound heterozygous c.826delG (p.Asp276Metfs*21) and c.2441G>A (p.Arg814His) variants in the BUB1B gene, which were inherited from her father and mother, respectively. CONCLUSION: The compound heterozygous variants of the BUB1B gene probably underlie the pathogenesis in this patient.

[Clinical features and mutational analysis of a case with Sensenbrenner syndrome].

OBJECTIVE: To explore the clinical characteristics of a patient with Sensenbrenner syndrome (also called cranioectodermal dysplasia type 3) caused by mutation of intraflagellar transport (IFT) 43 gene. METHODS: The clinical data of the patient was retrospectively analyzed. The target genes was the patient were captured and subjected to next generation sequencing. Suspected mutations were verified through Sanger sequencing. RESULTS: The patient, a-13 year-and-5-month-old girl, was admitted for anemia and renal dysfunction for 8 months. Clinically, she has featured short stature, short limbs, brachydactylia, tooth agenesis, and retinal dystrophy, high-degree myopia, and chronic renal failure. Gene sequencing showed that she has carried a homozygous c.1A>G (p.M1V) mutation of the IFT43 gene, for which both of her parents were heterozygous carriers. CONCLUSION: c.1A>G (p.M1V) mutation of the C14ORF179/IFT43 gene is the cause for praecox chronic renal failure in children. Genetic testing can facilitate the diagnosis of this rare disorder. For affected families, prenatal diagnosis should be provided.