Methylcitric acid (MCA) analysis has been mainly utilized for the diagnosis of propionate disorders or as a second-tier test in newborn screening, but its utility for patients monitoring still needs to be established. We explored the potential contribution of MCA in the long-term management of organic acidurias. We prospectively evaluated plasma MCA and its relationship with disease biomarkers, clinical status, and disease burden in 22 patients, 13 with propionic acidemia (PA) and nine with methylmalonic acidemia (MMA) on standard treatment and/or after transplantation. Samples were collected at scheduled routine controls or during episodes of metabolic decompensation (MD), 10 patients were evaluated after transplantation (six liver, two combined liver and kidney, 2 kidney). MCA levels were higher in PA compared to MMA and its levels were not influenced by the clinical status (MD vs well state). In MMA, MCA was higher in elder patients and, along with fibroblast growth factor 21 (FGF21) and plasma methylmalonic acid, negatively correlated with GFR. In both diseases, MCA correlated with ammonia, glycine, lysine, C3, and

Over recent years, several reports have been published on unusual cases of osteonecrosis of the jaw (ONJ) in adults using second- and third-generation nitrogen-containing bisphosphonates such as pamidronate, alendronate, risedronate and zoledronate, but no case has ever been reported either in children or in adult patients taking neridronate. Children and adolescents affected by osteogenesis imperfecta (OI) could belong to a high-risk group for ONJ because bone fragility in OI is associated with a connective tissue malfunction. The purpose of this study is to evaluate the incidence of ONJ in a pediatric population treated with neridronate for OI. A total of 102 pediatric patients with OI who received neridronate infusions for a mean of 6.81 years (SD ± 3.06 years) were clinically assessed for possible ONJ. Eligibility criteria for participation included patients between 1.2 and 24 years old who received cyclical neridronate infusions for at least 1 year. All the patients were reviewed to determine duration, dosage and cumulative dose of their bisphosphonate therapy and were examined clinically to assess their oral health status. We have not demonstrated any occurrence of ONJ in our patients. In conclusion, at the moment insufficient data are available to prove a greater risk of ONJ in children with OI than in children affected by other forms of bone fragility. However, cases may emerge in future because the risk of ONJ seems to be related to the cumulative dose and the duration of therapy.

The aim of our study was to analyze the possible relationship between growing pains, vitamin D levels, and bone mineral status. We enrolled 33 children affected by growing pains. Their pain intensity was evaluated through a questionnaire using the Wong-Baker Faces Pain Rating Scale for pain assessment. Serum 25-hydroxyvitamin D (25-OH-D), parathyroid hormone (PTH), and alkaline phosphatase levels were measured as well. A quantitative ultrasound assessment (QUS) was also done, measuring both the amplitude-dependent speed of sound (AD-SOS) and the bone transmission time (BTT), correlating, respectively, with bone density and with cortical thickness. After 3 and 24 months of vitamin D supplementation, we re-evaluated pain intensity and laboratory results. After 24 months we re-assessed QUS parameters. At the beginning of the study the children reported a mean growing pain intensity of 7.5 ± 1.6 SD. The mean values of 25-OH-D and PTH levels were 15.7 ± 6.9 ng/ml and 57.3 ± 27.3 pg/ml, respectively. The AD-SOS Z score was -0.53 ± 1.19 SD, and the mean value of the BTT Z score was -0.72 ± 0.96 SD. After the first 3 months of vitamin D supplementation we observed an increase in 25-OH-D levels (34.1 ± 17.8, p < 0.001) and a reduction in both PTH levels (47.3 ± 30.6, p = 0.135) and pain intensity (2.7 ± 2.2, p < 0.001). After 24 months we observed a further significant reduction in the pain intensity (3.9 ± 3.4, p < 0.001) and in PTH levels (43.7 ± 28.5, p = 0.004) and an improvement in the QUS parameters, in particular in BTT Z scores (p = 0.014). Our study suggests an interesting relationship between growing pains, vitamin D levels and bone mineral status.

Fabry disease (FD) is a progressive multisystemic lysosomal storage disease. Early diagnosis by newborn screening (NBS) may allow for timely treatment, thus preventing future irreversible organ damage. We present the results of 5.5 years of NBS for FD by α-galactosidase A activity and globotriaosylsphingosine (lyso-Gb3) assays in dried blood spot through a multiplexed MS/MS assay. Furthermore, we report our experience with long-term follow-up of positive subjects. We screened more than 170,000 newborns and 22 males were confirmed to have a GLA gene variant, with an incidence of 1:7879 newborns. All patients were diagnosed with a variant previously associated with the later-onset phenotype of FD or carried an unclassified variant (four patients) or the likely benign p.Ala143Thr variant. All were asymptomatic at the last visit. Although lyso-Gb3 is not considered a reliable second tier test for newborn screening, it can simplify the screening algorithm when its levels are elevated at birth. After birth, plasma lyso-Gb3 is a useful marker for non-invasive monitoring of all positive patients. Our study is the largest reported to date in Europe, and presents data from long-term NBS for FD that reveals the current incidence of FD in northeastern Italy. Our follow-up data describe the early disease course and the trend of plasma lyso-Gb3 during early childhood.

Liver and liver/kidney transplantation are increasingly used in methylmalonic aciduria, but little is known on their impact on CNS. The effect of transplantation on neurological outcome was prospectively assessed in six patients preand post-transplant by clinical evaluation and by measuring disease biomarkers in plasma and CSF, in combination with psychometric tests and brain MRI studies. Primary (methylmalonic-and methylcitric acid) and secondary biomarkers (glycine and glutamine) significantly improved in plasma, while they remained unchanged in CSF. Differently, biomarkers of mitochondrial dysfunction (lactate, alanine, and related ratios) significantly decreased in CSF. Neurocognitive evaluation documented significant higher post-transplant developmental/cognitive scores and maturation of executive functions corresponding to improvement of brain atrophy, cortical thickness, and white matter maturation indexes at MRI. Three patients presented post-transplantation reversible neurological events, which were differentiated, by means of

No abstract

Pearson syndrome (PS) is a rare mitochondrial disorder that usually presents with transfusion-dependent macrocytic anemia, exocrine pancreatic dysfunction, and lactic acidosis. Typical bone marrow (BM) features are vacuolization in hematopoietic progenitors, hypocellularity, and ringed sideroblasts. At the neonatal age, PS may have a variable clinical onset. Moreover, there is little information about BM features at this age and the timing of their presentation. We report a neonatal case of PS that presented with refractory anemia and atypical BM features. We reviewed the BM findings in neonatal-onset PS cases to stress the importance and limitations of BM evaluation at this age.

The use of intravenous bisphosphonates has been linked to hypocalcemia both in children and adults with osteogenesis imperfecta (OI). The aims of this study were: (1) to investigate the incidence of hypocalcemia in the first 48 hours (T48) after neridronate infusion in a pediatric population with OI and (2) to assess any correlation between the baseline values of calcium, vitamin D (25-hydroxyvitamin D) and bone turnover markers, and the postinfusion calcium values. We conducted a prospective observational study on 37 pediatric patients. All patients were treated with a single infusion of neridronate at a dose of 1 to 2 mg/kg. The study provided two postinfusion reassessments: 24 hours (T24) and T48 after neridronate administration. Hypocalcemia was observed in 11% of patients at T24 and in 50% of patients at T48 from neridronate infusion. We observed a positive linear correlation between the baseline vitamin D values and postinfusion calcium values, both at baseline and at T24 and T48. Hypocalcemia was mild and asymptomatic in all cases. Postinfusion calcium levels were related to baseline vitamin D levels. Consequently, low vitamin D levels should be considered a significant risk factor for hypocalcemia and should be carefully investigated and treated before neridronate infusion.