Biallelic NAA60 variants with impaired n-terminal acetylation capacity cause autosomal recessive primary familial brain calcifications

Primary familial brain calcification (PFBC) is characterized by calcium deposition in the brain, causing progressive movement disorders, psychiatric symptoms, and cognitive decline. PFBC is a heterogeneous disorder currently linked to variants in six different genes, but most patients remain genetically undiagnosed. Here, we identify biallelic NAA60 variants in ten individuals from seven families with autosomal recessive PFBC. The NAA60 variants lead to loss-of-function with lack of protein N-terminal (Nt)-acetylation activity. We show that the phosphate importer SLC20A2 is a substrate of NAA60 in vitro. In cells, loss of NAA60 caused reduced surface levels of SLC20A2 and a reduction in extracellular phosphate uptake. This study establishes NAA60 as a causal gene for PFBC, provides a possible biochemical explanation of its disease-causing mechanisms and underscores NAA60-mediated Nt-acetylation of transmembrane proteins as a fundamental process for healthy neurobiological functioning

COL12A1 Gene Variant and a Review of the Literature: A Case Report of Ullrich Congenital Muscular Dystrophy

Introduction: Mutations in collagen type IV-associated genes lead to Ullrich congenital muscular dystrophy (UCMD) and Bethlem myopathy (BM). COL12A1 gene mutations have rarely been reported in patients with UCMD- and BM-like disorders not involving COL6 mutations. UCMD-2 results from homozygous mutations in the COL12A1 gene on the long arm of chromosome 6. Pathogenic variants in COL12A1 result in a rare congenital connective tissue/myopathy overlap syndrome under the heading of myopathic Ehlers-Danlos syndrome. COL12A1 dominant pathogenic variants have been rarely reported, and the phenotypic spectrum has not yet been identified. Case Presentation: We describe a female patient aged 2 years and 10 months exhibiting a milder phenotype who presented due to pronounced joint hyperlaxity, frequent falls, and skin lesions. Genetic analysis revealed a homozygous c.8903C>T (p.Pro2968Leu) missense variant that had previously been described but concerning which there had been no clinical report, in the COL12A1 gene. Discussion/Conclusion: This report is presented in order to raise awareness of rare mutations in the COL12A1 gene that affect muscle and connective tissue and to add to the literature in defining the phenotypic spectrum

Evaluation of immunization status in patients with cerebral palsy: a multicenter CP-VACC study

Children with chronic neurological diseases, including cerebral palsy (CP), are especially susceptible to vaccine-preventable infections and face an increased risk of severe respiratory infections and decompensation of their disease. This study aims to examine age-appropriate immunization status and related factors in the CP population of our country. This cross-sectional prospective multicentered survey study included 18 pediatric neurology clinics around Turkey, wherein outpatient children with CP were included in the study. Data on patient and CP characteristics, concomitant disorders, vaccination status included in the National Immunization Program (NIP), administration, and influenza vaccine recommendation were collected at a single visit. A total of 1194 patients were enrolled. Regarding immunization records, the most frequently administrated and schedule completed vaccines were BCG (90.8%), hepatitis B (88.9%), and oral poliovirus vaccine (88.5%). MMR was administered to 77.3%, and DTaP-IPV-HiB was administered to 60.5% of patients. For the pneumococcal vaccines, 54.1% of children received PCV in the scope of the NIP, and 15.2% of children were not fully vaccinated for their age. The influenza vaccine was administered only to 3.4% of the patients at any time and was never recommended to 1122 parents (93.9%). In the patients with severe (grades 4 and 5) motor dysfunction, the frequency of incomplete/none vaccination of hepatitis B, BCG, DTaP-IPV-HiB, OPV, and MMR was statistically more common than mild to moderate (grades 1-3) motor dysfunction (p = 0.003, p < 0.001, p < 0.001, p < 0.00, and p < 0.001, respectively). Physicians' influenza vaccine recommendation was higher in the severe motor dysfunction group, and the difference was statistically significant (p = 0.029)

Biallelic NAA60 variants with impaired N-terminal acetylation capacity cause autosomal recessive primary familial brain calcifications

Primary familial brain calcification (PFBC) is characterized by calcium deposition in the brain, causing progressive movement disorders, psychiatric symptoms, and cognitive decline. PFBC is a heterogeneous disorder currently linked to variants in six different genes, but most patients remain genetically undiagnosed. Here, we identify biallelic NAA60 variants in ten individuals from seven families with autosomal recessive PFBC. The NAA60 variants lead to loss-of-function with lack of protein N-terminal (Nt)-acetylation activity. We show that the phosphate importer SLC20A2 is a substrate of NAA60 in vitro. In cells, loss of NAA60 caused reduced surface levels of SLC20A2 and a reduction in extracellular phosphate uptake. This study establishes NAA60 as a causal gene for PFBC, provides a possible biochemical explanation of its disease-causing mechanisms and underscores NAA60-mediated Nt-acetylation of transmembrane proteins as a fundamental process for healthy neurobiological functioning

Biallelic NAA60 variants with impaired n-terminal acetylation capacity cause autosomal recessive primary familial brain calcifications

Primary familial brain calcification (PFBC) is characterized by calcium deposition in the brain, causing progressive movement disorders, psychiatric symptoms, and cognitive decline. PFBC is a heterogeneous disorder currently linked to variants in six different genes, but most patients remain genetically undiagnosed. Here, we identify biallelic NAA60 variants in ten individuals from seven families with autosomal recessive PFBC. The NAA60 variants lead to loss-of-function with lack of protein N-terminal (Nt)-acetylation activity. We show that the phosphate importer SLC20A2 is a substrate of NAA60 in vitro. In cells, loss of NAA60 caused reduced surface levels of SLC20A2 and a reduction in extracellular phosphate uptake. This study establishes NAA60 as a causal gene for PFBC, provides a possible biochemical explanation of its disease-causing mechanisms and underscores NAA60-mediated Nt-acetylation of transmembrane proteins as a fundamental process for healthy neurobiological functioning

Biallelic NAA60 variants with impaired n-terminal acetylation capacity cause autosomal recessive primary familial brain calcifications.

Primary familial brain calcification (PFBC) is characterized by calcium deposition in the brain, causing progressive movement disorders, psychiatric symptoms, and cognitive decline. PFBC is a heterogeneous disorder currently linked to variants in six different genes, but most patients remain genetically undiagnosed. Here, we identify biallelic NAA60 variants in ten individuals from seven families with autosomal recessive PFBC. The NAA60 variants lead to loss-of-function with lack of protein N-terminal (Nt)-acetylation activity. We show that the phosphate importer SLC20A2 is a substrate of NAA60 in vitro. In cells, loss of NAA60 caused reduced surface levels of SLC20A2 and a reduction in extracellular phosphate uptake. This study establishes NAA60 as a causal gene for PFBC, provides a possible biochemical explanation of its disease-causing mechanisms and underscores NAA60-mediated Nt-acetylation of transmembrane proteins as a fundamental process for healthy neurobiological functioning

Re-examining the characteristics of pediatric multiple sclerosis in the era of antibody-associated demyelinating syndromes

Background: The discovery of anti-myelin oligodendrocyte glycoprotein (MOG)-IgG and anti-aquaporin 4 (AQP4)-IgG and the observation on certain patients previously diagnosed with multiple sclerosis (MS) actually have an antibody-mediated disease mandated re-evaluation of pediatric MS series. Aim: To describe the characteristics of recent pediatric MS cases by age groups and compare with the cohort established before 2015. Method: Data of pediatric MS patients diagnosed between 2015 and 2021 were collected from 44 pediatric neurology centers across Türkiye. Clinical and paraclinical features were compared between patients with disease onset before 12 years (earlier onset) and ≥12 years (later onset) as well as between our current (2015–2021) and previous (2015) cohorts. Results: A total of 634 children (456 girls) were enrolled, 89 (14%) were of earlier onset. The earlier-onset group had lower female/male ratio, more frequent initial diagnosis of acute disseminated encephalomyelitis (ADEM), more frequent brainstem symptoms, longer interval between the first two attacks, less frequent spinal cord involvement on magnetic resonance imaging (MRI), and lower prevalence of cerebrospinal fluid (CSF)-restricted oligoclonal bands (OCBs). The earlier-onset group was less likely to respond to initial disease-modifying treatments. Compared to our previous cohort, the current series had fewer patients with onset 12 years, initial presentation with ADEM-like features, brainstem or cerebellar symptoms, seizures, and spinal lesions on MRI. The female/male ratio, the frequency of sensorial symptoms, and CSF-restricted OCBs were higher than reported in our previous cohort. Conclusion: Pediatric MS starting before 12 years was less common than reported previously, likely due to exclusion of patients with antibody-mediated diseases. The results underline the importance of antibody testing and indicate pediatric MS may be a more homogeneous disorder and more similar to adult-onset MS than previously thought. © 2022 European Paediatric Neurology SocietyThe authors thank all their colleagues for their help in the follow-up of the patients. Note added in proof: part of the patients in the present cohort were included in the newly published study: Solmaz I, Doran T, Yousefi M, Konuskan B, Oncel I, Vural A, Anlar B. Frequency of myelin oligodendrocyte glycoprotein antibodies in pediatric onset multiple sclerosis. Mult Scler Relat Disord. 2022 Aug 8;68:104097. doi: 10.1016/j.msard.2022.104097. Epub ahead of print. PMID: 35998500

Re-examining the characteristics of pediatric multiple sclerosis in the era of antibody-associated demyelinating syndromes.

Background: The discovery of anti-myelin oligodendrocyte glycoprotein (MOG)-IgG and anti-aquaporin 4 (AQP4)-IgG and the observation on certain patients previously diagnosed with multiple sclerosis (MS) actually have an antibody-mediated disease mandated re-evaluation of pediatric MS series. Aim: To describe the characteristics of recent pediatric MS cases by age groups and compare with the cohort established before 2015. Method: Data of pediatric MS patients diagnosed between 2015 and 2021 were collected from 44 pediatric neurology centers across Turkiye. Clinical and paraclinical features were compared between patients with dis-ease onset before 12 years (earlier onset) and >= 12 years (later onset) as well as between our current (2015-2021) and previous (< 2015) cohorts. Results: A total of 634 children (456 girls) were enrolled, 89 (14%) were of earlier onset. The earlier-onset group had lower female/male ratio, more frequent initial diagnosis of acute disseminated encephalomyelitis (ADEM), more frequent brainstem symptoms, longer interval between the first two attacks, less frequent spinal cord involvement on magnetic resonance imaging (MRI), and lower prevalence of cerebrospinal fluid (CSF)-restricted oligoclonal bands (OCBs). The earlier-onset group was less likely to respond to initial disease-modifying treatments. Compared to our previous cohort, the current series had fewer patients with onset < 12 years, initial presentation with ADEM-like features, brainstem or cerebellar symptoms, seizures, and spinal lesions on MRI. The female/male ratio, the frequency of sensorial symptoms, and CSF-restricted OCBs were higher than reported in our previous cohort. Conclusion: Pediatric MS starting before 12 years was less common than reported previously, likely due to exclusion of patients with antibody-mediated diseases. The results underline the importance of antibody testing and indicate pediatric MS may be a more homogeneous disorder and more similar to adult-onset MS than previously thought