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.

Early prediction of pediatric asthma in the Canadian Healthy Infant Longitudinal Development (CHILD) birth cohort using machine learning.

Background: Early identification of children at risk of asthma can have significant clinical implications for effective intervention and treatment. This study aims to disentangle the relative timing and importance of early markers of asthma.

Methods: Using the CHILD Cohort Study, 132 variables measured in 1754 multi-ethnic children were included in the analysis for asthma prediction.

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.

Delayed gut microbiota maturation in the first year of life is a hallmark of pediatric allergic disease.

Allergic diseases affect millions of people worldwide. An increase in their prevalence has been associated with alterations in the gut microbiome, i.e.

Dominant negative variants in cause ICHAD syndrome, a new disorder characterised by immunodysregulation, craniofacial anomalies, hearing impairment, athelia and developmental delay.

Background: Helios (encoded by ), a member of the Ikaros family of transcription factors, is a zinc finger protein involved in embryogenesis and immune function. Although predominantly recognised for its role in the development and function of T lymphocytes, particularly the CD4 regulatory T cells (Tregs), the expression and function of Helios extends beyond the immune system. During embryogenesis, Helios is expressed in a wide range of tissues, making genetic variants that disrupt the function of Helios strong candidates for causing widespread immune-related and developmental abnormalities in humans.

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.

Breastfeeding enrichment of B. longum subsp. infantis mitigates the effect of antibiotics on the microbiota and childhood asthma risk.

Background: Early antibiotic exposure is linked to persistent disruption of the infant gut microbiome and subsequent elevated pediatric asthma risk. Breastfeeding acts as a primary modulator of the gut microbiome during early life, but its effect on asthma development has remained unclear.

Methods: We harnessed the CHILD cohort to interrogate the influence of breastfeeding on antibiotic-associated asthma risk in a subset of children (n = 2,521).

Can tandem alternative splicing and evasion of premature termination codon surveillance contribute to attenuated Peutz-Jeghers syndrome?

Alternative use of short distance tandem sites such as NAGN AG are a common mechanism of alternative splicing; however, single nucleotide variants are rarely reported as likely to generate or to disrupt tandem splice sites. We identify a pathogenic intron 5 STK11 variant (NM_000455.4:c.

A Novel Germline Heterozygous Variant Causing Severe Atopic Disease and Immune Dysregulation.

B-cell lymphoma/leukemia 11B (BCL11B) is a CH zinc finger transcription factor that is critically important for regulating the development and function of a variety of systems including the central nervous system, the skin, and the immune system. Germline heterozygous variants are associated with a spectrum of clinical disorders, including severe combined immunodeficiency as well as neurological, craniofacial, and dermal defects. Of these individuals, ~50% present with severe allergic disease.

Idiopathic splenomegaly in childhood and the spectrum of RAS-associated lymphoproliferative disease: a case report.

Background: KRAS (KRAS proto-oncogene, GTPase; OMIM: 190,070) encodes one of three small guanosine triphosphatase proteins belonging to the RAS family. This group of proteins is responsible for cell proliferation, differentiation and inhibition of apoptosis. Gain-of-function variants in KRAS are commonly found in human cancers.

Exome sequencing enables diagnosis of X-linked hypohidrotic ectodermal dysplasia in patient with eosinophilic esophagitis and severe atopy.

X-linked hypohidrotic ectodermal dysplasia (XLHED) is the most common form of ectodermal dysplasia. Clinical and genetic heterogeneity between different ectodermal dysplasia types and evidence of incomplete penetrance and variable expressivity increase the potential for misdiagnosis. We describe a family with X-linked hypohidrotic ectodermal dysplasia (XLHED) presenting with variable expressivity of symptoms between affected siblings.

Recurrent sterile abscesses in a case of X-linked neutropenia.

Cutaneous manifestations are common in monogenic immune disorders, including both infectious and non-infectious etiologies. We report follow-up of a case initially published in Pediatric Dermatology in 2001 of a 13-year-old boy with a history of inflammatory skin lesions and neutropenia who developed neutrophilic dermatoses precipitated by G-CSF. Whole exome sequencing performed at 36 years of age revealed a gain-of-function mutation in the WAS gene, leading to a diagnosis of X-linked neutropenia.

A Germline Mutation in the C2 Domain of PLCγ2 Associated with Gain-of-Function Expands the Phenotype for PLCG2-Related Diseases.

We report three new cases of a germline heterozygous gain-of-function missense (p.(Met1141Lys)) mutation in the C2 domain of phospholipase C gamma 2 (PLCG2) associated with symptoms consistent with previously described auto-inflammation and phospholipase Cγ2 (PLCγ2)-associated antibody deficiency and immune dysregulation (APLAID) syndrome and pediatric common variable immunodeficiency (CVID). Functional evaluation showed platelet hyper-reactivity, increased B cell receptor-triggered calcium influx and ERK phosphorylation.

IVIg and LPS Co-stimulation Induces IL-10 Production by Human Monocytes, Which Is Compromised by an FcγRIIA Disease-Associated Gene Variant.

Intravenous Immunoglobulin (IVIg) is used to treat autoimmune or inflammatory diseases, but its mechanism of action is not completely understood. We asked whether IVIg can induce interleukin-10 (IL-10) and reduce pro-inflammatory cytokine production in human monocytes, and whether this response is reduced in monocytes from people with an Fcγ receptor IIA (FcγRIIA) gene variant, which is associated with increased risk of inflammatory diseases and poor response to antibody-based biological therapy. IVIg increased IL-10 production and reduced pro-inflammatory cytokine production in response to bacterial lipopolysaccharide (LPS), which required FcγRI and FcγRIIB and activation of MAPKs, extracellular signal-regulated kinase 1/2 (ERK1/2), and p38.

The importance of considering monogenic causes of autoimmunity: A somatic mutation in KRAS causing pediatric Rosai-Dorfman syndrome and systemic lupus erythematosus.

Objectives: Clinicians need to be aware of the growing list of defined monogenic etiologies of autoimmune diseases. This is particularly relevant when evaluating children, as these rare monogenic forms of autoimmunity tend to present very early in life.

Methods And Results: By harnessing the transformative power of next generation sequencing, we made the unifying diagnosis of RAS-associated autoimmune leukoproliferative disease (RALD), caused by the somatic gain-of-function p.

Successful clinical treatment and functional immunological normalization of human MALT1 deficiency following hematopoietic stem cell transplantation.

MALT1 mutations impair normal NF-κB activation and paracaspase activity to cause a novel combined immunodeficiency. The clinical and immunological phenotype of MALT1 deficiency can be successfully treated with hematopoietic stem cell transplantation following reduced intensity conditioning.

IRAK-4 deficiency as a cause for familial fatal invasive infection by Streptococcus pneumoniae.

In this Letter to the Editor we report the case of two siblings with fatal pneumococcal meningitis as the initial manifestation of IRAK-4 deficiency caused by previously undescribed mutations in IRAK4. The letter also highlights the importance of invasive pneumococcal infection as a critical 'red flag' warning of the potential for an underlying primary immunodeficiency and identifies some of the challenges in making the clinical diagnosis of IRAK-4 deficiency.