Hyper IgE syndromes (HIES) are rare primary immunodeficiency characterized by susceptibility to specific infections, eczema, and elevated IgE levels. Pathogenic mutations in STAT3, IL6R, IL6ST, ERBB2IP, PGM3, ZNF431, SPINK5, TGFBR1/2, and CARD11 have been identified as genetic factors contributing to phenotypes of HIES lead to hindered differentiation and activity, aberrant signaling cascades and disrupting immune regulation. HIES present a diverse clinical symptoms, challenging diagnosis and management; understanding its pathophysiology, genetics, and immunological abnormalities offer hope for improved outcomes. In this review we aim to provide a comprehensive understanding of the condition and also discuss latest updates on pathological features, clinical spectrum and its variability, immunological abnormalities, inheritance patterns, new candidate genes, challenges, management strategies, epidemiology and future directions of HIES. This review conducted an extensive search of information from multiple databases, including PubMed, Scopus, WHO, and ClinVar to ensure comprehensive coverage. Preference was given to articles published recently to capture the latest research and developments. Endnote was employed as a reference manager. The relevant literature was meticulously reviewed to address the objectives of the study. Missense, nonsense, and frameshift variants are commonly observed in HIES. Understanding these genetic mutations is key to diagnosing and managing conditions such as Hyper-IgE recurrent infection syndromes (linked to IL6R, STAT3, and ZNF341 mutations), Atopy associated with ERBIN mutations which links STAT3 and TGF-β pathway, Immunodeficiency 23 (caused by PGM3 mutations), Netherton syndrome (resulting from SPINK5 mutations), and Loeys-Dietz syndrome (related to TGFBR mutations). Each year, new genes and variants responsible for this type of immune deficiency are added to the list. Although rare, HIES significantly impacts patients due to its complex medical manifestations and need for lifelong management. Identifying casual variants is essential for effective clinical management of these complex conditions.

Primary atopic disorders (PAD) are monogenic disorders caused by pathogenic gene variants encoding proteins that are key for the maintenance of a healthy skin barrier and a well-functioning immune system. Physicians face the challenge to find single, extremely rare PAD patients/families among the millions of individuals with common allergic diseases. We describe case scenarios with signature PAD. We review the literature and deduct specific clinical red flags for PAD detection. They include a positive family history and/or signs of pathological susceptibility to infections, immunodysregulation, or syndromic disease. Results of conventional laboratory and most immunological lab studies are not sufficient to make a definitive diagnosis of PAD. In the past, multistep narrowing of differential diagnoses by various immunological and other laboratory tests led to testing of single genes or gene panel analyses, which was a time-consuming and often unsuccessful approach. The implementation of whole-genomic analyses in the routine diagnostics has led to a paradigm shift. Upfront genome-wide analysis by whole genome sequencing (WGS) will shorten the time to diagnosis, save patients from unnecessary investigations, and reduce morbidity and mortality. We propose a rational, clinical landmark-based approach for deciding which cases pass the filter for carrying out early WGS. WGS result interpretation requires a great deal of caution regarding the causal relationship of variants in PAD phenotypes and absence of proof by adequate functional tests. In case of negative WGS results, a re-iteration attitude with re-analyses of the data (using the latest data base annotation)) may eventually lead to PAD diagnosis. PAD, like many other rare genetic diseases, will only be successfully managed, if physicians from different clinical specialties and geneticists interact regularly in multidisciplinary conferences.

Typical hyper-IgE syndromes (HIES) are caused by autosomal-dominant-negative (DN) variants of STAT3 (Signal Transducer And Activator Of Transcription 3) or IL6ST (Interleukin 6 Cytokine Family Signal Transducer), biallelic partial loss-of-function (LOF) variants of IL6ST, or biallelic complete LOF variants of ZNF341 (Zinc Finger Protein 341). Including the two new cases described in this review, only 20 patients with autosomal-recessive (AR) ZNF341 deficiency have ever been reported. Patients with AR ZNF341 deficiency have clinical and immunological phenotypes resembling those of patients with autosomal-dominant STAT3 deficiency, but with a usually milder clinical presentation and lower NK (Natural Killer) cell counts. ZNF341-deficient cells have 50% the normal level of STAT3 in the resting state. However, as there is no clear evidence that STAT3 haploinsufficiency causes HIES, this decrease alone is probably insufficient to explain the HIES phenotype observed in the ZNF341-deficient patients. The combination of decreased basal expression level and impaired autoinduction of STAT3 observed in ZNF341-deficient lymphocytes is considered a more likely pathophysiological mechanism. We review here what is currently known about the ZNF341 gene and ZNF341 deficiency, and briefly discuss possible roles for this protein in addition to its control of STAT3 activity.

Hyper IgE syndromes (HIES) are a group of rare primary immunodeficiency characterized by high levels of serum IgE, cold abscesses, pulmonary infections, and eczema. ZNF341 deficiency was described in 2018 in 11 patients clinically diagnosed previously with HIES. Eight of those patients, all offspring of consanguineous couples, are from three families who live in a Muslim village in Israel which has approximately 15,000 residents. Our study aimed to evaluate the prevalence of ZNF341 mutation in the population of the village. Three hundred DNA samples of females were included in the study. The samples belong to females that were referred to the Meir Medical Center for prenatal genetic testing before pregnancy, during 2017-2019: 200 samples were from the village, and 100 samples of Muslim females were from other villages.All samples were tested by Sanger sequencing for the ZNF341 mutation (c.904C>T, NM_001282933.1). Heterozygous nonsense mutation in ZNF341 was found in ten samples (5%) of the study group compared to zero in the control group (p<0.01). The carrier frequency of the mutation in ZNF341 in the studied village population is 1:20. This high frequency is probably due to founder mutation and consanguineous marriages.