Autism spectrum disorder is a neurodevelopmental disorder with a heterogeneous presentation, the etiology of which is not clearly elucidated. In recent years, comorbidity has become more evident with the increase in the frequency of autism and diagnostic possibilities of inborn errors of metabolism. One hundred and seventy-nine patients with diagnosis of autism spectrum disorder who presented to the Pediatric Metabolism outpatient clinic between 01/September/2018-29/February/2020 constituted the study population. The personal information, routine and specific metabolic tests of the patients were analyzed retrospectively. Out of the 3261 patients who presented to our outpatient clinic, 179 (5.48%) were diagnosed with autism spectrum disorder and were included in the study. As a result of specific metabolic examinations performed, 6 (3.3%) patients were diagnosed with inborn errors of metabolism. Two of our patients were diagnosed with classical phenylketonuria, two with classical homocystinuria, one with mucopolysaccharidosis type 3D (Sanfilippo syndrome) and one with 3-methylchrotonyl Co-A carboxylase deficiency. Inborn errors of metabolism may rarely present with autism spectrum disorder symptoms. Careful evaluation of the history, physical examination and additional findings in patients diagnosed with autism spectrum disorder will guide the clinician in the decision-making process and chose the appropriate specific metabolic investigation. An underlying inborn errors of metabolism may be a treatable cause of autism.

[Multiple sclerosis (MS) is typically a disease of young adults. Childhood MS can be defined in patients under 18 years of age, although some authors set the limit un­der the age of 16 formerly known as “early-onset multiple sclerosis” or “juvenile multiple sclerosis”, seen in 3-5% of all MS patients. Nowadays, owing to ever-evolving, better diagnostic tools and well-traced, strictly defined diagnostic criteria, childhood MS is showing an increasing incidence worldwide (0.05-2.85/100 000). MS is characterized by recurrent episodes of the central nervous system with demyelination separated in space and time. In childhood almost exclusively the relapsing-remitting (RR) type of MS occurs. Based on experience in adults, the goal in the pediatric population is also the early diagnosis, to initiate adequate DMT as soon as possible and to achieve symptom relief and good quality of life. Based on efficacy and safety studies in the adult population, inter­feron β-1a and glatiramer acetate were first approved by the FDA and EMA for the treatment of childhood MS also. The increased relapse rate and rapid progression of childhood MS and unfavorable therapeutic response to nearly 45% of the first DMT necessitated the testing of more effective and second-line drugs in the population under 18 years of age (PARADIGMS, CONNECT). Although natalizumab was reported to be effective and well-tolerated in highly active RRMS in childhood, evidence based studies were not yet available when our patients’ treatment started. In this article, we report on the successful treatment of three active RRMS patients with individually authorized off-label use of natalizumab.]

[Inflammatory diseases of the central nervous system (CNS) are relatively rare in children, but their relevance to public health is considerable due to frequent and significant long term morbidity and even mortality. As in adults, acute disseminated encephalomyelitis (ADEM) and multiple sclerosis (MS) and their variants are the most common entities in this group of pathologies in the pediatric patient population. Recent efforts have focused on establishing standardized diagnostic criteria schemes to facilitate the diagnosis and differential diagnosis of these diseases, however especially with multiple sclerosis those have not been fully validated yet for disease occurring in children. In recent decades the role of MRI has been constantly increasing in the diagnostic work-up of suspected inflammatory diseases of the CNS as well as in the follow-up of patients with confirmed disease. Currently, MRI is the first-line diagnostic imaging modality in ADEM and MS and is fully integrated in the most widely used diagnostic criteria schemes, but it has a key role in clinical therapeutic research trials as well. This paper provides an update on the current concepts and strategies of MRI in inflammatory diseases of the CNS, as well as a review of the imaging semiology of the various disease entities and variants with emphasis on clinical and imaging particularities relevant to the pediatric patient population.]

[X-linked hypophosphataemia (XLH) is the most common inherited cause of phosphate wasting. Its pathogenesis is complex, determined by the dysregulation of phosphate homeostasis and bone metabolism. We review herein the pathophysiology of XLH leading to multiple manifestations, stages of diagnosis and the treatment strategies. XLH is now in the scientific interest of pediatric nephrology, because a new treatment modality, burosumab became available in Hungary. Burosumab is a monoclonal antibody against fibroblast growth factor 23 (FGF-23). XLH is caused by the loss of function mutations in ”phosphate regulating endopeptidase homolog, X-linked” (PHEX) gene, which results enhanced secretion of the phosphaturic hormone FGF-23. The diagnosis of XLH is based on signs of rickets and/or osteomalacia and decreased growth velocity in association with hypophosphataemia and renal phosphate wasting in the absence of vitamin D or calcium deficiency. Conventional treatment with oral phosphate supplementation together with active vitamin D (calcitriol or alfadiol) can improve bone metabolism, but only partial results can be achieved, and can promote side effects (nephrocalcinosis). The better understanding of the role of PHEX gene and FGF-23 levels in the pathomechanism helped to identify therapeutic options more properly. With monoclonal antibody therapy against FGF-23 the disease process can be interrupted, and complications can be prevented if the therapy is initiated in time. However, deformities already leading to disability cannot regress completely during burosumab therapy, highlighting the need of early diagnosis and the start of the biological treatment before complications.]