What's known on this topic? Hypomagnesemia is one of the causes of hypocalcemia. Enteral replacement is the key in the treatment but the treatment should be individualized for each patient. Normalization of hypomagnesemia is not always easy and should not be the aim of the treatment. What this study adds? The genetic analysis revealed a novel frame shift variant in the transient receptor potential melastatin 6 genes. The magnesium levels varied during the treatment with different preparations of medication. The treatment should be individualized.

Systemic pseudohypoaldosteronism (PHA) is a rare, salt-wasting syndrome that is caused by inactivating variants in genes encoding epithelial sodium channel subunits. Hyponatremia, hyperkalemia, metabolic acidosis, increased aldosterone and renin levels are expected findings in PHA. Clinical management is challenging due to high dose oral replacement therapy. Furthermore, patients with systemic PHA require life-long therapy. Here we report a patient with systemic PHA due to SCNN1B variant whose hyponatremia and hyperkalemia was detected at the 24 th hour of life. Hyperkalemia did not improve with conventional treatments and dialysis was required. He also developed myocarditis and hypertension in follow-up. Challenges for diagnosis and treatment in this patient are discussed herein. In addition, published evidence concerning common features of patients with SCNN1B variant are reviewed.

Objective: Free hormones are biologically more active in target tissues. Thus, measurement of vitamin D taking into account bioavailability and free vitamin D may be preferable, especially when evidence is contradictory, as in obese children. In order to assess bioavailablity and free vitamin D, using a previously reported formula, vitamin D-binding protein (VDBP) level was measured and VDBP polymorphisms were also evaluated because of variations in binding affinity. Methods: Eighty-four obese and 78 healthy children were included. Anthropometry, calcium, phosphorus, alkaline-phosphatase, parathyroid hormone (PTH), 25 hydroxyvitamin D [25(OH)D], bioavailable-free vitamin D, and VDBP concentration and polymorphism were evaluated in the whole group. Results: Obese girls had significantly higher PTH than normal weight girls (p=0.001). Regardless of gender, obese children had significantly higher concentrations of VDBP (p=0.008) and PTH (p=0.002). When samples taken in winter were analyzed, PTH and VDBP were found to be higher and bioavailable and free vitamin D lower in the obese group. There was no difference in terms of total vitamin D between groups during the winter season. Conclusion: While total, free, and bioavailable vitamin D in the obese group was similar to the control group in autumn, free and bioavailable vitamin D in the winter was lower in the obese than the control group. In addition, PTH was higher in the obese group in both autumn and winter. Therefore, more research is needed to evaluate the variability of free and bioavailable vitamin D according to body habitus, season and the effect any differences may have.

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Background Kawasaki disease (KD) is an acute, self‐limited, systemic vasculitis of unknown etiology. In the present study, we investigated whether there is a relationship between KD and dynamic thiol/disulphide homeostasis. Methods This case–control study involved KD patients and healthy controls. Plasma total, native and disulphide thiol and the disulphide/native, disulphide/total and native thiol/total thiol ratios of all patients and the control group were analyzed simultaneously. Results A total of 20 patients with KD (male/female, 12/8) and 25 age‐ and gender‐matched healthy controls (male/female, 12/13) were evaluated. Native, total thiol and native thiol/total thiol ratio were significantly lower in KD patients than in the control group (P < 0.001). In contrast, disulphide thiol, disulphide/native thiol and disulphide/total thiol ratios were significantly higher in KD patients than control subjects (P < 0.001). In KD patients with coronary artery lesion (CAL), the native thiol and total thiol were significantly lower than in KD patients without CAL. In KD patients with CAL, the ratios of disulphide/total thiol and disulphide/native thiol were significantly higher than in those without CAL (P = 0.02 and P = 0.02, respectively), whereas the ratio of native/total thiol was significantly lower (P = 0.02). Conclusion The KD patients had lower plasma thiol (native and total) and higher disulphide thiol than controls, indicating that dynamic thiol/disulphide homeostasis might be an important indicator of inflammation in KD. Alteration and shifting of thiol/disulphide homeostasis to the oxidized side are correlated with the pathogenesis of KD and CAL.

Objectives  Laron syndrome (LS) is a disease caused by growth hormone receptor (GHR) defects. It is characterized by severe postnatal growth retardation and distinctive facial features. Case presentation In this case report, we describe the clinical and biochemical characteristics of two siblings with LS, a sister and a brother, and identify a homozygous c.344A> C (p.Asn115Thr) variant in GHR. The sister was 11 years 9 months old with a height of 127.5 cm (-3.86 SDS), and the brother was 14 years 10 months old with a height of 139 cm (-4.27 SDS). Their phenotype did not have features suggesting classical LS. Conclusion In the current literature, there are three cases with the same missense variant. Our cases differ from them in clinical (higher height SDS, mild dysmorphism including a broad forehead, malar hypoplasia, prominent columella and chin, thick lips) and biochemical characteristics. Here, we present the variable expressivity in the two siblings.

ÖzETAmaç: Nutrisyonel rikets, D vitamini destek programlarına karşın halen dünya genelinde önemli ve önlenebilir bir halk sağlığı sorunu olmaya devam etmektedir. Yazıda 2011-2015 yılları arasında çocuk endokrinoloji polikliniğimizde izlediği-miz 14 nutrisyonel riketsli olgunun klinik, laboratuvar ve radyolojik bulgularını değerlendirmeyi amaçladık. Gereç ve ABSTRAcTObjective: Nutritional rickets is a major public health problem throughout the world. Although vitamin D supplementation program has been applied in our country, it is still an important health problem. Accordingly, this study aims to determine clinical, laboratory and radiological characteristics of 14 patients with nutritional rickets followed by the endocrinology clinic between 2011 and 2015. Material and Methods:Fourteen patients who diagnosis with nutritional rickets in Dr. Sami Ulus Obstetrics and Gynecology, Children's Health and Disease Training and Research Hospital Peadiatric Endocrine Clinic between 2011-2015 were evaluated. Results:The mean age of the fourteen cases with nutritional rickets was 14.3 ± 7.3 (4-28) months. Nine (64%) of the patients were male and five (36%) were female. Vitamin D prophylaxis had never been used in 6 patients whereas it has been used irregularly in 6 patients. Additionally, five patients had hypocalcemia and 8 patients had hypophosphatemia. Alkaline phosphatase and parathyroid hormone levels were higher than normal levels in all cases. In all patients except for one, 25 (OH) vitamin D levels were below 20 ng/mL. Wrist radiographs of all patients had irregular metaphyseal distal radius and ulna irregularity and cupping. Six patients were treated with stoss therapy, 7 patients were treated with longterm vitamin D. One patient refused treatment. After treatment all cases showed clinical and radiological improvement.conclusion: Although vitamin D prophylaxis had been recommended to our patients, we still observed nutritional rickets. This is due to the fact that a significant proportion of our patients did not use vitamin D completely or used it irregularly. Therefore, improving compliance with the vitamin D supplementation program in infancy is essential for the prevention of nutritional rickets.

In recent years, interest in the evaluation of vitamin D levels and the possible outcomes of their deficiency during pregnancy has increased. However, there is no consensus on when to start vitamin D supplementation, its duration, dosage, and the optimum level during pregnancy. The toxicity of vitamin D is as important as its deficiency. From the history of a 5-day-old male baby who was investigated for hypercalcemia, it was learned that the mother took 300,000 IU vitamin D-five ampoules/oral at 30 weeks of gestation every other day. The infant was born prematurely, postpartum bradycardia required positive pressure ventilation, and his hypercalcemia lasted approximately 4 months despite treatment. Maternal excessive and inappropriate use of vitamin D can cause preterm labor and severe hypercalcemia, which is a life-threatening complication in the neonatal period. This case is presented to draw attention to the negative effects of maternal high-dose vitamin D during pregnancy.