ASXL1 deficiency causes epigenetic dysfunction, combined immunodeficiency, and EBV-associated lymphoma.

Inborn errors of immunity (IEIs) are caused by deleterious variants in immune-related genes. ASXL1 is an epigenetic modifier not previously linked to an IEI. Clonal hematopoiesis and hematologic neoplasms often feature somatic ASXL1 variants, and Bohring-Opitz syndrome, a neurodevelopmental disorder, is caused by heterozygous truncating ASXL1 variants.

STAT6 gain-of-function disease: p.D519N is a new disease-causing variant that responds well to dupilumab treatment.

This case report presents a new genetic variant that causes STAT6 gain-of-function disease in 2 patients, expands the clinical phenotype of STAT6 gain-of-function disease, and describes its authors' success in using therapeutics to manage this rare disease.

A multimorphic variant in ThPOK causes an inborn error of immunity with T cell defects and fibrosis.

ThPOK is a transcription factor that acts as a master regulator of CD4+ T cell lineage commitment. We report the first human disease caused by a genetic alteration in ThPOK, specifically, a damaging heterozygous de novo variant in ThPOK (NM_001256455.2:c.

Primary atopic disorders: inborn errors of immunity causing severe allergic disease.

Allergic diseases, including asthma, allergic rhinitis, atopic dermatitis, and food allergies, are driven by dysregulated immune responses, often involving IgE-mediated mast cell and basophil activation, Th2 inflammation, and epithelial dysfunction. While environmental factors are well-known contributors, the genetic components underpinning these conditions are increasingly understood. Traditionally viewed as polygenic multifactorial disorders, allergic diseases can also be caused by single-gene defects affecting the immune system and skin epithelial barrier, leading to profoundly dysregulated allergic responses.

Naturally occurring splice variants dissect the functional domains of BHC80 and emphasize the need for RNA analysis.

Pathogenic PHF21A variation causes PHF21A-related neurodevelopmental disorders (NDDs). Although amorphic alleles, including haploinsufficiency, have been established as a disease mechanism, increasing evidence suggests that missense variants as well as frameshift variants extending the BHC80 carboxyl terminus also cause disease. Expanding on these, we report a proposita with intellectual disability and overgrowth and a novel de novo heterozygous PHF21A splice variant (NM_001352027.

Gain-of-function MARK4 variant associates with pediatric neurodevelopmental disorder and dysmorphism.

Microtubule affinity-regulating kinase 4 (MARK4) is a serine/threonine kinase that plays a key role in tau phosphorylation and regulation of the mammalian target of rapamycin (mTOR) pathway. Abnormal tau phosphorylation and dysregulation of the mTOR pathway are implicated in neurodegenerative and neurodevelopmental disorders. Here, we report a gain-of-function variant in in two siblings with childhood-onset neurodevelopmental disability and dysmorphic features.

Transcription factor defects in inborn errors of immunity with atopy.

Transcription factors (TFs) are critical components involved in regulating immune system development, maintenance, and function. Monogenic defects in certain TFs can therefore give rise to inborn errors of immunity (IEIs) with profound clinical implications ranging from infections, malignancy, and in some cases severe allergic inflammation. This review examines TF defects underlying IEIs with severe atopy as a defining clinical phenotype, including STAT3 loss-of-function, STAT6 gain-of-function, FOXP3 deficiency, and T-bet deficiency.

Generation of tandem alternative splice acceptor sites and CLTC haploinsufficiency: A cause of CLTC-related disorder.

Tandem splice acceptors (NAGN AG) are a common mechanism of alternative splicing, but variants that are likely to generate or to disrupt tandem splice sites have rarely been reported as disease causing. We identify a pathogenic intron 23 CLTC variant (NM_004859.4:c.