Genotypes and phenotypes heterogeneity in PIK3CA-related overgrowth spectrum and overlapping conditions: 150 novel patients and systematic review of 1007 patients with PIK3CA pathogenetic variants.

BACKGROUND: Postzygotic activating PIK3CA variants cause several phenotypes within the PIK3CA-related overgrowth spectrum (PROS). Variant strength, mosaicism level, specific tissue involvement and overlapping disorders are responsible for disease heterogeneity. We explored these factors in 150 novel patients and in an expanded cohort of 1007 PIK3CA-mutated patients, analysing our new data with previous literature to give a comprehensive picture. METHODS: We performed ultradeep targeted next-generation sequencing (NGS) on DNA from skin biopsy, buccal swab or blood using a panel including phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin pathway genes and GNAQ, GNA11, RASA1 and TEK. Additionally, 914 patients previously reported were systematically reviewed. RESULTS: 93 of our 150 patients had PIK3CA pathogenetic variants. The merged PROS cohort showed that PIK3CA variants span thorough all gene domains, some were exclusively associated with specific PROS phenotypes: weakly activating variants were associated with central nervous system (CNS) involvement, and strongly activating variants with extra-CNS phenotypes. Among the 57 with a wild-type PIK3CA allele, 11 patients with overgrowth and vascular malformations overlapping PROS had variants in GNAQ, GNA11, RASA1 or TEK. CONCLUSION: We confirm that (1) molecular diagnostic yield increases when multiple tissues are tested and by enriching NGS panels with genes of overlapping 'vascular' phenotypes; (2) strongly activating PIK3CA variants are found in affected tissue, rarely in blood: conversely, weakly activating mutations more common in blood; (3) weakly activating variants correlate with CNS involvement, strong variants are more common in cases without; (4) patients with vascular malformations overlapping those of PROS can harbour variants in genes other than PIK3CA.

Expanding the novel MAPKAPK5-related developmental disorder's genotype-phenotype correlation: Patient report and 19 months of follow-up.

This study aimed to widen the knowledge of a recently identified, autosomal-recessive, multiple congenital anomalies syndrome to date observed in only other three children. This is the second report of biallelic mutations in MAPKAPK5 whose impairment during human development has been associated with neurological, cardiac, and facial anomalies combined with fingers and toes malformations. Through the affected patients' genetic and phenotypic features overlap, this report confirms MAPKAPK5 as causative gene and adds unique neurodevelopmental characterization. Moreover, based on the complex congenital genitourinary anomalies reported and MAPKAPK5 literature review, we also propose kidney and external genitalia involvement as a key syndromic feature whose expressivity may be more severe in males.

Dysregulated miRNAs in bone cells of patients with Gorham-Stout disease.

Gorham-Stout disease (GSD) is a very rare disease characterized by increased bone erosion with angiomatous proliferation. The mechanisms underlying this disorder have not been deeply investigated. Due to its rarity, no guidelines are currently available for treatment and management of GSD. We recently evaluated the cellular alterations of the bone remodeling in patients showing that osteoclast precursors displayed increased ability to differentiate into osteoclasts and that affected osteoclasts resorb bone more actively than control cells. Moreover, osteoblasts isolated from a patient showed a defective ability to form mineralized nodules. In this paper, we investigated the molecular pathways involved in the cellular defects of GSD bone cells. For this study, we recruited nine patients and performed miRNome analysis of bone cells. Between the 178 miRNAs robustly expressed in GSD osteoclasts, significant modulation of three miRNAs (miR-1246, miR-1-3p, and miR-137-3p) involved in the regulation of osteoclast formation and activity or in the angiomatous proliferation was found in patients' cells. Interestingly, miR-1246 was also up-regulated in serum exosomes from patients. Analysis of miRNAs from patient osteoblasts suggested alteration of miR-204a-5p, miR-615-3p and miR-378a-3p regulating osteoblast function and differentiation. The resulting miRNA pattern may help to understand better the mechanisms involved in GSD and to identify new potential therapeutic targets for this rare disease.

Langerhans cell histiocytosis in a young patient with Pitt-Hopkins syndrome.

Pitt-Hopkins syndrome (PTHS, MIM #610954) is a rare neurodevelopmental disease characterized by the association of intellectual disability, characteristic facial gestalt and episodes of abnormal and irregular breathing. PTHS is due to heterozygous loss-of-function variants in the TCF4 gene (transcription factor 4, MIM #602272) encoding for a basic helix-loop-helix transcription factor. TCF4 is highly expressed during early development of the nervous system, and it is involved in cellular differentiation and proliferation. Since the first clinical description in 1978, less than 200 PTHS patients have been described. A comprehensive phenotype, especially regarding cancer predisposition, is not yet well defined. We report the case of a 7-year-old boy affected by PTHS with a 4-week history of progressive swelling of the frontal bones diagnosed with Langerhans cell histiocytosis.

Borderline cognitive level in a family with Bazex-Dupré-Christol syndrome.

Bazex-Dupré-Christol syndrome (BDCS) [OMIM 301845] is an X-linked dominant disorder of the hair follicle characterized by multiple basal cell carcinomas, follicular atrophoderma, congenital hypotrichosis, and hypohidrosis. Additional features include multiple milia, trichoepitheliomas, and axillary hidradenitis suppurativa as well as a variety of other symptoms. Some patients with a diagnosis of BDCS have had poor school performance. But no other associated psychopathological disorders have been described in the literature. We describe the neuropsychological characteristics and the co-occurring psychopathological disorders in an Italian family (brother and sister, and their mother) affected by BDCS. The BDCS phenotype in this family was characterized by hypotrichosis, atrophoderma follicularis, milia, and trichoepitheliomas. No basal cell carcinomas were documented. At neuropsychological assessment the three affected family members all had a borderline cognitive level. Other identified psychopathological disorders included attention deficit hyperactivity disorder, executive deficits, academic difficulties, deficits in lexical skills, and internalizing problems. The presence of cognitive impairment in the three family members affected by BDCS suggests that cognitive impairment may be associated with the syndrome. It may be useful to assess neuropsychological performance in patients with BDCS to identify possible associated neuropsychological disorders.

A novel mutation in the CIAS1/NLRP3 gene associated with an unexpected phenotype of cryopyrin-associated periodic syndromes.

OBJECTIVES: Cryopyrin-associated periodic syndromes (CAPS) comprise a spectrum of distinct, rare, autosomal dominant autoinflammatory disorders of increasing severity caused by NLRP3 gene mutations. METHODS: We describe a 13-year-old female who presented, in the initial phase of the disease, recurrent episodes of high fever, pericarditis, arthralgia, arthritis of the knees, abdominal pain and marked increase in inflammatory markers. In the subsequent months she developed recurrent episodes of chest pain, skin rash and swelling of the subcutaneous tissue, without fever, and with spontaneous resolution. RESULTS: Molecular analysis of the CIAS1 gene revealed the presence of the Q703K variant and also a c.1105C>A mutation in the heterozygous state, that predicts a L369M amino acid substitution. The latter variant has never been reported. The L369M mutation was predicted to significantly affect protein structure (scoring as 'dangerous' and 'deleterious') by the Variant Effect Predictor tool. Therapy with anakinra was started with rapid disappearance of clinical symptoms and normalization of CRP levels in 24 hours. CONCLUSIONS: The rapid response to IL-1 inhibition suggests that the disease of this patient is driven by IL-1 and supports the conclusion that this novel mutation is pathogenic and may be associated with a new CAPS phenotype. The role played by the concomitant presence of the mutation Q703K remains to be clarified.

Lomitapide for the treatment of paediatric patients with homozygous familial hypercholesterolaemia (APH-19): results from the efficacy phase of an open-label, multicentre, phase 3 study.

BACKGROUND: Homozygous familial hypercholesterolaemia (HoFH) is a rare inherited disorder characterised by extremely high concentrations of LDL cholesterol, leading to early-onset atherosclerosis. Lomitapide is an orally administered microsomal triglyceride transfer protein (MTP) inhibitor that effectively lowers LDL cholesterol and is approved for adults with HoFH. We aimed to investigate the efficacy and safety of lomitapide in paediatric patients with HoFH receiving standard-of-care lipid-lowering therapy. METHODS: APH-19 is an open-label, single-arm, phase 3 trial performed at 12 study centres in Germany, Israel, Italy, Saudi Arabia, Spain, and Tunisia. A 6-week run-in period was followed by a 24-week efficacy phase and an 80-week safety phase. Patients aged 5-17 years, on stable lipid-lowering therapy, with HoFH diagnosed using the criteria from the 2014 European Atherosclerosis Society Consensus Panel on HoFH were titrated to maximum tolerated doses of oral lomitapide, starting at 2 mg (patients aged 5-15 years) or 5 mg (patients aged 16-17 years). The primary endpoint was the percentage change from baseline to week 24 in LDL cholesterol, which was assessed in patients who had received at least one dose of lomitapide, and who had a baseline and at least one post-baseline measurement. The secondary outcomes were the percentage change from baseline at week 24 in total cholesterol, non-HDL cholesterol, VLDL cholesterol, apolipoprotein B, triglycerides, and lipoprotein(a). Safety was assessed in patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, NCT04681170. FINDINGS: Between Dec 20, 2020, and Oct 16, 2022, 43 patients were included and treated (24 [56%] were female and 19 [44%] were male, and median age was 10·7 years [7·0-14·0]). Mean change from baseline in LDL cholesterol at week 24 was -53·5% (95% CI -61·6 to -45·4, p<0·0001). Mean percentage reductions were observed at week 24 for non-HDL cholesterol (-53·9%, 95% CI -61·7 to -46·1, p<0·0001), total cholesterol (-50·0%, 95% CI -57·6 to -42·4, p<0·0001), VLDL cholesterol (-50·2%, -59·1 to -41·2, p<0·0001), apolipoprotein B (-52·4%, -60·3 to -44·5, p<0·0001), triglycerides was -49·9% (-58·8 to -41·0, p<0·0001), and lipoprotein(a) (-11·3%, -32·9 to 10·3 [in 21 patients with measurements in mg/dL]; -23·6%, -38·2 to -9·0 [in 22 patients with measurements in nmol/L]; p=0·0070 combined). Adverse events were mostly mild, and gastrointestinal and hepatic in nature. Adverse events of special interest were reported for five (12%) patients (gastrointestinal in two patients and hepatic in three). One serious treatment-emergent adverse event was reported (also classed as an adverse event of special interest): an increase in hepatic enzymes, resulting in two dose interruptions, two dose reductions, and a repeated dose escalation. INTERPRETATION: Lomitapide provided a significant, clinically meaningful LDL cholesterol reduction and has the potential to be an efficient, LDL receptor-independent option for paediatric patients with HoFH. FUNDING: Amryt Pharmaceuticals.

Unique Features of Cardiovascular Involvement and Progression in Children with Marfan Syndrome Justify Dedicated Multidisciplinary Care.

Marfan syndrome (MIM: # 154700; MFS) is an autosomal dominant disease representing the most common form of heritable connective tissue disorder. The condition presents variable multiorgan expression, typically involving a triad of cardiovascular, eye, and skeletal manifestations. Other multisystemic features are often underdiagnosed. Moreover, the disease is characterized by age related penetrance. Diagnosis and management of MFS in the adult population are well-described in literature. Few studies are focused on MFS in the pediatric population, making the clinical approach (cardiac and multiorgan) to these cases challenging both in terms of diagnosis and serial follow-up. In this review, we provide an overview of MFS manifestations in children, with extensive revision of major organ involvement (cardiovascular ocular and skeletal). We attempt to shed light on minor aspects of MFS that can have a significant progressive impact on the health of affected children. MFS is an example of a syndrome where an early personalized approach to address a dynamic, genetically determined condition can make a difference in outcome. Applying an early multidisciplinary clinical approach to MFS cases can prevent acute and chronic complications, offer tailored management, and improve the quality of life of patients.

Necrosis of the tongue as first symptom of Polyarteritis Nodosa (PAN): unusual presentation of a rare disease in children.

Polyarteritis or panarteritis nodosa (PAN) is a necrotizing, focal segmental vasculitis that affects predominantly medium-sized arteries in many different organ systems. It is extremely rare in childhood. Involvement of the oral mucosa at diagnosis is uncommon in PAN. Here, we report a case of a pediatric patient with tongue necrosis.

Long-term follow-up in a pediatric patient with Ligneous Conjunctivitis due to PLG gene mutation in topical plasminogen treatment after successful use of ocular prosthesis for aesthetic rehabilitation: a case report.

BACKGROUND: Ligneous Conjunctivitis (LC) is the most common clinical manifestation of Type I Plasminogen deficiency (T1PD; OMIM# 217090), and it is characterized by the formation of pseudomembranes (due to deposition of fibrin) on the conjunctivae leading to progressive vision loss. In past times, patients with LC were treated with surgery, topical anti-inflammatory, cytostatic agents, and systemic immunosuppressive drugs with limited results (Blood 108:3021-3026, 2006, Ophthalmology 129:955-957, 2022, Surv Ophthalmol 48:369-388, 2003, Blood 131:1301-1310, 2018). The surgery can also trigger the development of membranes, as observed in patients needing ocular prosthesis (Surv Ophthalmol 48:369-388, 2003). Treatment with topical purified plasminogen is used to prevent pseudomembranes formation (Blood 108:3021-3026, 2006, Ophthalmology 129:955-957, 2022). CASE PRESENTATION: We present the case of a sixteen-year-old girl with LC with severe left eye involvement. We reported the clinical conditions of the patient before and after the use of topical plasminogen eye drops and described the treatment schedule allowing the surgical procedure for the pseudomembranes debulking and the subsequent use of ocular prosthesis for aesthetic rehabilitation. CONCLUSIONS: The patient showed a progressive response to the topical plasminogen, with a complete absence of pseudomembrane formation at a twelve-year follow-up, despite using an ocular prosthesis.

Work-Up and Treatment Strategies for Individuals with PIK3CA-Related Disorders: A Consensus of Experts from the Scientific Committee of the Italian Macrodactyly and PROS Association.

PIK3CA-related disorders encompass many rare and ultra-rare conditions caused by somatic genetic variants that hyperactivate the PI3K-AKT-mTOR signaling pathway, which is essential for cell cycle control. PIK3CA-related disorders include PIK3CA-related overgrowth spectrum (PROS), PIK3CA-related vascular malformations and PIK3CA-related non-vascular lesions. Phenotypes are extremely heterogeneous and overlapping. Therefore, diagnosis and management frequently involve various health specialists. Given the rarity of these disorders and the limited number of centers offering optimal care, the Scientific Committee of the Italian Macrodactyly and PROS Association has proposed a revision of the most recent recommendations for the diagnosis, molecular testing, clinical management, follow-up, and treatment strategies. These recommendations give insight on molecular diagnosis, eligible samples, preferable sequencing, and validation methods and management of negative results. The purpose of this paper is to promote collaboration between health care centers and clinicians with a joint shared approach. Finally, we suggest the direction of present and future research studies, including new systemic target therapies, which are currently under evaluation in several clinical trials, such as specific inhibitors that can be employed to downregulate the signaling pathway.

Exploiting in silico structural analysis to introduce emerging genotype-phenotype correlations in DHCR24-related sterol biosynthesis disorder: a case study.

Desmosterolosis is a rare sterol biosynthesis disorder characterized by multiple congenital anomalies, failure to thrive, severe developmental delay, progressive epileptic encephalopathy, and elevated levels of desmosterol caused by biallelic mutations of DHCR24 encoding 3-ß-hydroxysterol Δ-24-reductase. DHCR24 is regarded as the key enzyme of cholesterol synthesis in the metabolism of brain cholesterol as it catalyzes the reduction of the Δ-24 double bond of sterol intermediates during cholesterol biosynthesis. To date, 15 DHCR24 variants, detected in 2 related and 14 unrelated patients, have been associated with the desmosterolosis disorder. Here, we describe a proband harboring the never-described DHCR24 homozygous missense variant NM_014762.4:c.506T>C, NP_055577.1:p.M169T, whose functional validation was confirmed through biochemical assay. By using molecular dynamics simulation techniques, we investigated the impact of this variant on the protein stability and interaction network with the flavin adenine dinucleotide cofactor, thereby providing a preliminary assessment of its mechanistic role in comparison to all known pathogenic variants, the wild-type protein, and a known benign DHCR24 variant. This report expands the clinical and molecular spectra of the DHCR24-related disorder, reports on a novel DHCR24 deleterious variant associated with desmosterolosis, and gives new insights into genotype-phenotype correlations.

Clinical Approach in the Management of Paediatric Patients with Familial Hypercholesterolemia: A National Survey Conducted by the LIPIGEN Paediatric Group.

Detection and treatment of patients with familial hypercholesterolemia (FH) starting from childhood is fundamental to reduce morbidity and mortality. The activity of National realities such as the LIPIGEN (LIpid transPort disorders Italian GEnetic Network) Paediatric Group, founded in 2018, is a milestone in this context. The aim of this exploratory survey, conducted in October 2021 among Italian lipid clinics included in the LIPIGEN Paediatric Group, was to investigate the current clinical approach in the management and treatment of paediatric patients with suspected FH. A digital questionnaire composed of 20 questions investigating nutritional treatment and nutraceutical and pharmacological therapy for children and adolescents with FH was proposed to the principal investigators of 30 LIPIGEN centres. Twenty-four centres responded to the section referring to children aged < 10 years and 30 to that referring to adolescents. Overall, 66.7% of children and 73.3% of adolescents were given lipid-lowering nutritional treatment as the first intervention level for at least 3-4 months (29.2% and 23.3%) or 6-12 months (58.3% and 53.3%). Nutraceuticals were considered in 41.7% (regarding children) and 50.0% (regarding adolescents) of the centres as a supplementary approach to diet. Lipid-lowering drug therapy initiation was mainly recommended (91.7% and 80.0%). In 83.3% of children and 96.7% of adolescents, statins were the most frequently prescribed drug. We highlighted several differences in the treatment of paediatric patients with suspected FH among Italian centres; however, the overall approach is in line with the European Atherosclerosis Society (EAS) recommendations for FH children and adolescents. We consider this survey as a starting point to reinforce collaboration between LIPIGEN centres and to elaborate in the near future a consensus document on the management of paediatric patients with suspected FH so as to improve and uniform detection, management, and treatment of these patients in our country.

Longitudinal myelitis in systemic lupus erythematosus: a paediatric case.

Acute transverse myelitis (ATM) is a very rare manifestation of the central nervous system in systemic lupus erythematosus (SLE), especially in case of involvement of continuous segments (longitudinal myelitis). We describe a 12-year-old female with lupus correlated with transverse myelitis with a longitudinal involvement of the spinal cord (D2 to D10) at the onset of the disease. Despite the administration of an early aggressive therapy, the outcome proved to be unfavourable. After 2 years of follow-up, the child still complains of paraplegia, sphincter incontinency and ipo-paresthesias of both legs.

Paediatric patients with heterozygous familial hypercholesterolaemia treated with evolocumab for 80 weeks (HAUSER-OLE): a single-arm, multicentre, open-label extension of HAUSER-RCT.

BACKGROUND: The HAUSER-RCT study showed that 24 weeks of evolocumab (a proprotein convertase subtilisin/kexin type 9 [PCSK9] inhibitor) in paediatric patients with heterozygous familial hypercholesterolaemia was safe and improved lipid parameters compared to placebo. Here, we aimed to evaluate the safety and efficacy of evolocumab in this population for an additional 80 weeks. METHODS: HAUSER-OLE was an 80-week, single-arm, open-label extension of HAUSER-RCT, a randomised controlled trial, and was conducted at 46 centres in 23 countries. Paediatric patients aged 10-17 years with heterozygous familial hypercholesterolaemia who completed 24 weeks of monthly treatment with subcutaneously administered placebo or 420 mg evolocumab in HAUSER-RCT with no serious treatment-emergent adverse events were eligible to enrol in HAUSER-OLE. All patients received open-label subcutaneous evolocumab 420 mg monthly with background statins with or without ezetimibe for 80 additional weeks. The primary endpoint was treatment-emergent adverse events. Efficacy was evaluated by changes in lipids from the baseline of HAUSER-RCT to the end of HAUSER-OLE (104 weeks). This study is registered with ClinicalTrials.gov (NCT02624869) and is now completed. FINDINGS: Between Sept 10, 2016, and Nov 25, 2019, 157 patients were enrolled in HAUSER-RCT and received randomised treatment; 150 continued to HAUSER-OLE, received evolocumab treatment, and were included in the full analysis set, presented here. 146 (97%) of 150 patients completed the open-label extension. The incidence of treatment-emergent adverse events in HAUSER-OLE was 70% (105 of 150). Overall, the most common treatment-emergent adverse events were nasopharyngitis (22 [15%] of 150), headache (14 [9%]), and influenza-like illness (13 [9%]). Serious treatment-emergent adverse events occurred in four (3%) of 150 patients (perforated appendicitis and peritonitis, wrist fracture, anorexia nervosa, and headache); none was considered related to evolocumab. No treatment-emergent adverse events led to treatment discontinuation. At week 80, the mean percentage change from baseline in LDL cholesterol was -35·3% (SD 28·0). INTERPRETATION: After 80 weeks of treatment, evolocumab was safe, well tolerated, and led to sustained reductions in LDL cholesterol in paediatric patients with heterozygous familial hypercholesterolaemia. When lipid goals cannot be achieved with conventional treatments, evolocumab is an effective add-on therapy in paediatric patients. FUNDING: Amgen. TRANSLATIONS: For the French, Spanish, Spanish, Portuguese, Italian and Dutch translations of the abstract see Supplementary Materials section.

Characterization of Extracellular Vesicles in Osteoporotic Patients Compared to Osteopenic and Healthy Controls.

Extracellular vesicles (EVs) are mediators of a range of pathological conditions. However, their role in bone loss disease has not been well understood. In this study we characterized plasma EVs of 54 osteoporotic (OP) postmenopausal women compared to 48 osteopenic (OPN) and 44 healthy controls (CN), and we investigated their effects on osteoclasts and osteoblasts. We found no differences between the three groups in terms of anthropometric measurements and biochemical evaluation of serum calcium, phosphate, creatinine, PTH, 25-hydroxy vitamin D and bone biomarkers, except for an increase of CTX level in OP group. FACS analysis revealed that OP patients presented a significantly increased number of EVs and RANKL+ EVs compared with both CN and OPN subjects. Total EVs are negatively associated with the lumbar spine T-score and femoral neck T-score. Only in the OPN patients we observed a positive association between the total number of EVs and RANKL+ EVs with the serum RANKL. In vitro studies revealed that OP EVs supported osteoclastogenesis of healthy donor peripheral blood mononuclear cells at the same level observed following RANKL and M-CSF treatment, reduced the ability of mesenchymal stem cells to differentiate into osteoblasts, while inducing an increase of OSTERIX and RANKL expression in mature osteoblasts. The analysis of miRNome revealed that miR-1246 and miR-1224-5p were the most upregulated and downregulated in OP EVs; the modulated EV-miRNAs in OP and OPN compared to CN are related to osteoclast differentiation, interleukin-13 production and regulation of canonical WNT pathway. A proteomic comparison between OPN and CN EVs evidenced a decrease in fibrinogen, vitronectin, and clusterin and an increase in coagulation factors and apolipoprotein, which was also upregulated in OP EVs. Interestingly, an increase in RANKL+ EVs and exosomal miR-1246 was also observed in samples from patients affected by Gorham-Stout disease, suggesting that EVs could be good candidate as bone loss disease biomarkers. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Infliximab therapy in pediatric Takayasu's arteritis: report of two cases.

Takayasu arteritis (TA) is a chronic vasculitis of unknown etiology. Experience with anti-tumor necrosis factor alpha (anti-TNF) agents in difficult-to-treat patients with TA is limited and refers to adult patients. Here, we present two cases of pediatric TA treated with infliximab, in which clinical remission was observed. Anti-TNF treatment represents a useful therapy in pediatric Takayasu arteritis too, especially to avoid the risk of long-term corticosteroids toxicity.