Genotypic and phenotypic features in Turkish patients with classic nonketotic hyperglycinemia.

Nonketotic hyperglycinemia is an autosomal recessive inborn error of glycine metabolism, characterized by deficient activity of the glycine cleavage enzyme system. Classic nonketotic hyperglycinemia is caused by mutations or genomic changes in genes that encode the protein components of the glycine cleavage enzyme system. We aimed to investigate clinical, biochemical, radiological findings and molecular genetic data in ten Turkish patients with classic nonketotic hyperglycinemia. Ten Turkish patients who were diagnosed with classic nonketotic hyperglycinemia in a single center from 2013 to 2019 were included in this study. Their clinical, radiological, electrophysiological and laboratory data were collected retrospectively. Sixty percent of the patients were in neonatal group, while 40 % of the patients were infantile. There were no late-onset patients. 90 % of the patients had the severe form. All patients had developmental delay and seizures. Mortality ratio was 30 % in all groups and 50 % in the neonatal group, while no mortality was seen in infantile group. Median (range) values of cerebrospinal fluid (CSF) glycine levels, plasma glycine levels and CSF/plasma glycine ratios were 148 (15-320) µmol/L, 896 (87-1910) µmol/L, 0.17 (0.09-0.21) respectively. Diffuse hypomyelination and corpus callosum anomaly were the most common cranial MRI findings and multifocal epileptic activity and burst supression pattern were the most common electroencephalographic findings. Six patients had variants in GLDC gene and four in AMT gene; five novel variants including AMT gene deletion were detected. Prognosis was poor and treatment was not effective, especially in the severe form. Classic nonketotic hyperglycinemia causes high morbidity and mortality. Neonatal-onset disease was more common and severe than infantile-onset disease. The ratio of AMT gene variants might be higher in Turkey than other countries. AMT gene deletion also plays a role in the etiology of classic nonketotic hyperglycinemia.

A 7-year-old boy with scurvy owing to coeliac disease.

ABBREVIATIONS: ESR: erythrocyte sedimentation rate; Hb: haemoglobin; HSP: Henoch-Schönlein purpura; WCC: white-cell count.

Pterin Profiling in Serum, Dried Blood Spot, and Urine Samples Using LC-MS/MS in Patients with Inherited Hyperphenylalaninemia.

Background: Hyperphenylalaninemia (HPA) is defined as blood phenylalanine (Phe) levels exceeding the normal values (>120 µmol/L or >2 mg/dL) and is caused by a deficiency in the enzyme phenylalanine hydroxylase (PAH). The widespread screening of Phe levels in newborn screening programs has led to a very high number of patients with HPA. Methods: The samples were collected at various ages, not at the point of diagnosis. Nine pterin derivatives, including isoxanthopterin, sepiapterin, xanthopterin, primapterin, biopterin, neopterin, 7,8-dihydrobiopterin, 7,8-dihydroneopterin, and tetrahydrobiopterin (BH4), were analyzed in different HPA classes in serum, dried blood spots (DBS), and urine samples. A total of 18 patients, including six classical phenylketonuria (PKU), eight BH4-responsive PKU, and four mild HPA patients, were included in the study. Results: Among the nine pterin derivatives measured, a significant increase was observed in the levels of isoxanthopterin, biopterin, and 7,8-dihydrobiopterin in serum, dried blood spots (DBS), and urine samples of patients with HPA compared to the control group. However, elevations in isoxanthopterin, biopterin, and 7,8-dihydrobiopterin were observed in all HPA groups, although the extent of elevation varied among the different disease groups. There were also significant differences between HPA subgroups among these high values. Conclusion: In this study, it might be suggested that pterin profiling shows promising potential for its effective utilization in the differential diagnosis of HPA. Pterin profiling demonstrated its efficacy in accurately categorizing patients into distinct subtypes. This approach offers several notable advantages, including the ability to simultaneously screen multiple HPA subtypes through a single test, establish disease decision limits for pterins, shorten the time required for HPA differential diagnosis, reduce the risk of misdiagnosis, and increase overall diagnostic accuracy. This study is the most comprehensive study examining the association between HPA pterin in the literature. In our study, samples obtained from BH4-responsive PKU patients were on treatment. This may have affected the results. Preliminary findings on pterin profiles may need to be replicated in a prospective cohort of samples collected at the time of diagnosis to confirm the results.

Association Between Vitamin D Levels and COVID-19 Infection in Children: A Case-Control Study.

OBJECTIVE: Coronavirus disease 2019 (COVID-19) infection is seen in all age groups, and its symptoms are very variable. The course of the disease can be asymptomatic or mortal. In pediatric patients, vitamin D is thought to be protective against (COVID-19) with its immunomodulator, antiviral, anti-inflammatory, and epithelial integrity properties. Our aim is to investigate the relationship between (COVID-19) infection and vitamin D level. MATERIALS AND METHODS: We included (COVID-19) patients between 1 month and 18 years of age and healthy control groups. We compared epidemiological, clinical, laboratory, and imaging findings in patients. RESULTS: One hundred forty-nine patients were evaluated in our study. Seventy-three (49%) of them were (COVID-19)-positive patients and 76 (51%) of them were healthy control group. The mean 25(OH)-D vitamin level was 15.80 ng/mL (5-41.56) in (COVID-19) patients and 21.51 ng/mL (5-69.80) in the control group. Vitamin D level was shown to be statistically significantly lower in coronavirus disease 2019 patients (P < .001). It was observed that myalgia was more common in patients with low 25(OH)-D levels (P < .048). CONCLUSION: Our study is one of the rare studies examining the relationship between (COVID19) and 25(OH)-D vitamins in the pediatric age group. Children with (COVID-19) have a lower 25(OH)-D vitamin level than the control group.