Multidisciplinary Outpatient Clinic of Neurocutaneous Diseases: Five-year Experience of a Pediatric Tertiary Hospital in Portugal.

INTRODUCTION: Neurocutaneous syndromes (NCS) are a heterogeneous group of conditions with multiorgan involvement and diverse manifestations, evolving throughout life with significant morbidity. A multidisciplinary approach to NCS patients has been advocated, although a specific model is not yet established. The aim of this study was 1) to describe the organization of the recently created Multidisciplinary Outpatient Clinic of Neurocutaneous Diseases (MOCND) at a Portuguese pediatric tertiary hospital; 2) to share our institutional experience focusing on the most common conditions, neurofibromatosis type 1 (NF1) and tuberous sclerosis complex (TSC); 3) to analyze the advantages of a multidisciplinary center and approach in NCS. METHODS: Retrospective analysis of 281 patients enrolled in the MOCND over the first five years of activity (October 2016 to December 2021), reviewing genetics, family history, clinical features, complications, and therapeutic strategies for NF1 and TSC. RESULTS: The clinic works weekly with a core team of pediatricians and pediatric neurologists supported by other specialties as needed. Of the 281 patients enrolled, 224 (79.7%) had identifiable syndromes such as NF1 (n = 105), TSC (n = 35), hypomelanosis of Ito (n = 11), Sturge-Weber syndrome (n = 5), and others. In NF1 patients, 41.0% had a positive family history, all manifested café-au-lait macules, 38.1% neurofibromas with 45.0% being large plexiform neurofibromas. Sixteen were under treatment with selumetinib. Genetic testing was performed in 82.9% of TSC patients with pathogenic variants found in TSC2 gene in 72.4% patients (82.7% if considered contiguous gene syndrome). Family history was positive in 31.4%. All TSC patients presented hypomelanotic macules and fulfilled diagnostic criteria. Fourteen patients were being treated with mTOR inhibitors. CONCLUSION: Offering a systematic and multidisciplinary approach to NCS patients enables timely diagnosis, promotes a structured follow-up, and encourages discussion to outline management plans for optimal care to every patient, with significant impact on the quality of life of patients and families.

Case Report: Patient with deficiency of ADA2 presenting leukocytoclastic vasculitis and pericarditis during infliximab treatment.

Deficiency of adenosine deaminase 2 (DADA2), first reported in 2014, is a disease with great phenotypic variability, which has been increasingly reported. Therapeutic response depends on the phenotype. We present a case of an adolescent with recurrent fever, oral aphthous ulcers, and lymphadenopathy from 8 to 12 years of age and subsequently presented with symptomatic neutropenia. After the diagnosis of DADA2, therapy with infliximab was started, but after the second dose, she developed leukocytoclastic vasculitis and showed symptoms of myopericarditis. Infliximab was switched to etanercept, with no relapses. Despite the safety of tumor necrosis factor alpha inhibitors (TNFi), paradoxical adverse effects have been increasingly reported. The differential diagnosis between disease new-onset manifestations of DADA2 and side effects of TNFi can be challenging and warrants further clarification.

Recurrent pyogenic infections caused by a novel Gln1420* mutation in the C3 gene.

C3 is a crucial protein of the complement system. Congenital C3 deficiency is extremely rare and manifests through recurrent, severe infections and should always be considered as a differential diagnosis of recurrent pyogenic infections. We report a case of a patient with a novel C3 gene mutation, responsible for complete C3 deficiency with impaired complement system activation and recurrent infections.

Case Report: Wide Spectrum of Manifestations of Ligase IV Deficiency: Report of 3 Cases.

DNA ligase IV deficiency is a rare autosomal recessive disorder associated with impaired DNA repair mechanisms. Most patients with DNA repair defects present with neurologic deficits, combined immunodeficiency, bone marrow failure, and/or hematologic neoplasia. We present 3 unrelated cases of ligase IV deficiency with different clinical presentations. Patient 1 presented at the age of 5 with bone marrow failure, dysmorphic features, and T and B lymphopenia. A compound heterozygous variant L19W/K635fs in the LIG4 gene was identified. Patient 2 presented at the age of 16 with recurrent infections. He had agammaglobulinemia and absent B cells. A homozygous R278H in the LIG4 gene was identified. Patient 3 was referred for vitiligo and B-cell lymphopenia (low class-switched B cells) and hypogammaglobulinemia. Homozygous R278H in LIG4 was also identified. In the last few years, the spectrum of clinical manifestations caused by ligase IV deficiency has widened, making it very difficult to establish an accurate clinical diagnosis. The use of NGS allows a proper diagnosis and provides a better prognosis and adequate family counseling.

Case Report: Primary Immunodeficiencies, Massive EBV+ T-Cell Lympoproliferation Leading to the Diagnosis of ICF2 Syndrome.

In immunocompromised patients, EBV may elicit B-cell transformation and proliferation. A 5-year-old microcephalic boy was admitted with fever and non-malignant polymorphic T-cell lymphoproliferative disease associated with EBV. A presumptive diagnosis of primary immunodeficiency with inability to control EBV was made and next-generation sequencing led to the identification of a novel ZBTB24 mutation (ICF2-syndrome). This case shows that susceptibility to EBV seems to be particular of ICF-2 as it has not been described in the other types of ICF. It is mandatory to raise the hypothesis of an underlying PID in case of severe EBV infection.

A Novel TRAF3IP2 Mutation Causing Chronic Mucocutaneous Candidiasis.

Inborn errors of the IL-17-mediated signaling have been associated with chronic mucocutaneous candidiasis (CMC). We describe a patient with CMC, atopic dermatitis, enamel dysplasia, and recurrent parotitis harboring a novel compound heterozygous mutation of TRAF3IP2, leading to autosomal recessive ACT1 deficiency and deficient IL-17 signaling.

Fatal Meningitis in Patient with X-Linked Chronic Granulomatous Disease Caused by Virulent Granulibacter bethesdensis.

Granulibacter bethesdensis is a pathogen reported to cause recurrent lymphadenitis exclusively in persons with chronic granulomatous disease. We report a case of fatal meningitis caused by a highly virulent G. bethesdensis strain in an adolescent in Europe who had chronic granulomatous disease.

Defects in memory B-cell and plasma cell subsets expressing different immunoglobulin-subclasses in patients with CVID and immunoglobulin subclass deficiencies.

BACKGROUND: Predominantly antibody deficiencies (PADs) are the most prevalent primary immunodeficiencies, but their B-cell defects and underlying genetic alterations remain largely unknown. OBJECTIVE: We investigated patients with PADs for the distribution of 41 blood B-cell and plasma cell (PC) subsets, including subsets defined by expression of distinct immunoglobulin heavy chain subclasses. METHODS: Blood samples from 139 patients with PADs, 61 patients with common variable immunodeficiency (CVID), 68 patients with selective IgA deficiency (IgAdef), 10 patients with IgG subclass deficiency with IgA deficiency, and 223 age-matched control subjects were studied by using flow cytometry with EuroFlow immunoglobulin isotype staining. Patients were classified according to their B-cell and PC immune profile, and the obtained patient clusters were correlated with clinical manifestations of PADs. RESULTS: Decreased counts of blood PCs, memory B cells (MBCs), or both expressing distinct IgA and IgG subclasses were identified in all patients with PADs. In patients with IgAdef, B-cell defects were mainly restricted to surface membrane (sm)IgA+ PCs and MBCs, with 2 clear subgroups showing strongly decreased numbers of smIgA+ PCs with mild versus severe smIgA+ MBC defects and higher frequencies of nonrespiratory tract infections, autoimmunity, and affected family members. Patients with IgG subclass deficiency with IgA deficiency and those with CVID showed defects in both smIgA+ and smIgG+ MBCs and PCs. Reduced numbers of switched PCs were systematically found in patients with CVID (absent in 98%), with 6 different defective MBC (and clinical) profiles: (1) profound decrease in MBC numbers; (2) defective CD27+ MBCs with almost normal IgG3+ MBCs; (3) absence of switched MBCs; and (4) presence of both unswitched and switched MBCs without and; (5) with IgG2+ MBCs; and (6) with IgA1+ MBCs. CONCLUSION: Distinct PAD defective B-cell patterns were identified that are associated with unique clinical profiles.

Fatal Central Nervous System Lymphocytic Vasculitis after Treatment for Burkitt Lymphoma in a Patient with a SH2D1A Mutation.

Very rarely, patients with X-linked lymphoproliferative syndrome type 1 present central nervous system vasculitis. We report a patient carrying a SH2D1A mutation that, after treatment for lymphoma developed fatal central nervous system vasculitis. He lacked signs of ongoing Epstein-Barr virus infection. We propose that impaired T cell homeostasis caused by SAP deficiency facilitates aberrant CD8 T cell activation against vascular antigens promoting clinical manifestations.

Novel PLCG2 Mutation in a Patient With APLAID and Cutis Laxa.

Background: The auto-inflammation and phospholipase Cγ2 (PLCγ2)-associated antibody deficiency and immune dysregulation (APLAID) syndrome is a rare primary immunodeficiency caused by a gain-of-function mutation S707Y in the PLCG2 gene previously described in two patients from one family. The APLAID patients presented with early-onset blistering skin lesions, posterior uveitis, inflammatory bowel disease (IBD) and recurrent sinopulmonary infections caused by a humoral defect, but lacked circulating autoantibodies and had no cold-induced urticaria, contrary to the patients with the related PLAID syndrome. Case: We describe a new APLAID patient who presented with vesiculopustular rash in the 1st weeks of life, followed by IBD, posterior uveitis, recurrent chest infections, interstitial pneumonitis, and also had sensorineural deafness and cutis laxa. Her disease has been refractory to most treatments, including IL1 blockers and a trial with ruxolitinib has been attempted. Results: In this patient, we found a unique de novo heterozygous missense L848P mutation in the PLCG2 gene, predicted to affect the PLCγ2 structure. Similarly to S707Y, the L848P mutation led to the increased basal and EGF-stimulated PLCγ2 activity in vitro. Whole blood assays showed reduced production of IFN-γ and IL-17 in response to polyclonal T-cell stimulation and reduced production of IL-10 and IL-1ß after LPS stimulation. Reduced IL-1ß levels and the lack of clinical response to treatment with IL-1 blockers argue against NLRP3 inflammasome hyperactivation being the main mechanism mediating the APLAID pathogenesis. Conclusion: Our findings indicate that L848P is novel a gain-of-function mutation that leads to PLCγ2 activation and suggest cutis laxa as a possible clinical manifestations of the APLAID syndrome.

Missense mutation of TTC7A mimicking tricho-hepato-enteric (SD/THE) syndrome in a patient with very-early onset inflammatory bowel disease.

Tricho-hepato-enteric syndrome (SD/THE) and Multiple intestinal atresia with combined immune deficiency (MIA-CID) are autosomal recessive disorders that present immunological and gastrointestinal features. There are two different phenotypes of patients with TTC7A mutations: the severe form, caused by null mutations and leading to the classical MIA-CID; and the mild form, caused by missense mutations and leading to predominant features of VEO-IBD, less severe immunological involvement and hair abnormalities. We expand the knowledge about TTC7A deficiency, describing a patient with the mild phenotype of TTC7A deficiency but presenting overlapping features of SD/THE and MIA-CID: intestinal atresia and inflammatory bowel disease evocative of MIA-CID, but also dental abnormalities, huge forehead, liver abnormalities, autoimmune thyroiditis and hypogammaglobulinemia, evocative of SD/THE.

Beyond polycystic kidney disease.

Tuberous sclerosis(TS) is an autosomal dominant disease caused by mutations in TSC1 and TSC2 genes. TSC2 gene is located in chromosome 16p13.3, adjacent to PKD1 gene, responsible for the autosomal dominant polycystic kidney disease. In a rare subgroup of patients, the presence of a deletion which simultaneously affects the TSC2 and PKD1 genes has been confirmed. TSC2/PKD1-Contiguous Gene Syndrome is characterised by the early appearance of autosomal dominant polycystic kidney disease in combination with several phenotypic manifestations of TS. We present a 13-year-old girl with bilateral renal cysts detected at the age of 9 months. At the age of 13, she was referred to the Dermatology Outpatients Clinic due to a facial cutaneous eruption. She presented with facial erythema, fibroadenomas with malar distribution and disseminated hypomelanotic macules, meeting the criteria for TS. TSC2/PKD1 Contiguous Gene Syndrome deletion was suspected, being later confirmed by genetic testing.

Mosaic trisomy 18 in a five-month-old infant.

Individuals with mosaic trisomy 18, only approximately 5% of all trisomy 18 cases, carry both a trisomy 18 and an euploid cell line. Their clinical findings are highly variable, from the absence of dysmorphic features to the complete trisomy 18 syndrome. A five-month-old daughter of a 38-year-old mother, with vomiting and feeding problems, was referred to our department. She was undernourished and had axial hypotony and developmental delay, an irregular pattern of hypopigmentation on the right side of the abdomen, and moderate sagittal body asymmetry with left-side muscular hemihypotrophy. Mild craniofacial dysmorphy included dolichocephaly, frontal bossing, prominent occiput, long downslanting palpebral fissures, hypertelorism, and retrognathia. A complex heart defect with atrial and ventricular septal defects, pulmonary artery stenosis, and bicuspid aortic valve was identified. Cytogenetic analysis revealed mosaic trisomy 18 with trisomy in 90% of peripheral lymphocytes and 17% of skin fibroblasts. This case adds to our knowledge of the phenotypic spectrum and the natural history of mosaic trisomy 18 by adding a dysmorphic feature and a cardiac abnormality that, to the best of our knowledge, had not been previously described.