A Rare Presentation of 17α Hydroxylase/17,20 Lyase Deficiency in a Patient with non-Hodgkin's Lymphoma: A Case Report.

17α­hydroxylase/17,20­lyase deficiency (17OHD) is a rare form of congenital adrenal hyperplasia that causes decreased cortisol and sex steroid levels and leads to high production of adrenocorticotropic hormone (ACTH). Although affected patients have absolute cortisol deficiency, they do not show clinical signs of cortisol deficiency or hyperpigmentation. These patients most commonly present with delayed puberty and amenorrhea at late pubertal age. Impaired production of sex steroids leads to ambiguous or female external genitalia in affected 46, XY individuals. In this report, we describe a patient with 17OHD who presented with hyperpigmentation and hypergonodotropic hypogonadism while receiving chemotherapy.

Comprehensive Insights into Pediatric Craniopharyngioma: Endocrine and Metabolic Profiles, Treatment Challenges, and Long-term Outcomes with a Multicenter Approach.

Introduction: Craniopharyngiomas (CPG) have complex challenges in treatment due to their proximity to vital structures, surgical and radiotherapeutic complexities, and the tendency for recurrence. This study aims to identify the prevalence of endocrine and metabolic comorbidities observed during initial diagnosis and long-term follow-up in a nationwide cohort of pediatric CPG patients. The study also highlights the associated difficulties in their management. Methods: Sixteen centers entered 152 patients into the ÇEDD NET data system. We evaluated the clinical and laboratory characteristics at presentation, administered treatments, accompanying endocrine, metabolic, and other system involvements, and the patient's follow-up features. Results: Of the evaluated patients, 64 were female, and 88 were male. At presentation, the mean age was 9.1 ± 3.67 (min:1.46-max:16.92) years. The most common complaints at presentation were headache (68.4%), vision problems (42%), short stature (15%), nausea and vomiting (7%). The surgical procedure applied to the patients was gross total resection (GTR) in 97 cases (63.8%) and subtotal resection in 55 cases (36.2%). Radiotherapy was initiated in 11.8% of the patients. In the pathological examination, 92% of the cases were adamantinamatous type, 8% were papillary type. Postoperatively, hormone deficiencies consisted of thyroid-stimulating hormone (92.1%), adrenocorticotropic hormone (81%), antidiuretic hormone (79%), growth hormone (65.1%), and gonadotropin (43.4%) deficiencies. Recombinant growth hormone treatment (rhGH) was initiated on 27 patients. The study showed hesitancy among physicians regarding rhGH. The median survival without relapse was 2.2 years. Median time of relapse was 1.82 years (range: 0.13-10.35 years). Relapse was related to longer follow-ups and reduced GTR rates. The median follow-up time was 3.13 years. Among the last follow-up visits, the prevalence of obesity was 38%, but of these, 46.5% were already obese at diagnosis. However, 20% who were not obese at baseline became obese on follow-up. Permanent visual impairment was observed in 26 patients, neurological deficits in 13 patients, and diabetes mellitus in 5 patients. Conclusion: Recurrence was predominantly due to incomplete resection and the low rate of postoperative radiotherapy. It also emphasized challenges in multidisciplinary regular follow ups and suggested early interventions such as dietary restrictions and increased exercise to prevent obesity.

Clinical and Laboratory Characteristics of MODY (Maturity Onset Diabetes of Young) Cases, Genetic Mutation Spectrum and Phenotype-genotype Relationship.

Objective: Maturity-onset diabetes of the young (MODY) occurs due to mutations in genes involved in pancreatic beta cell function and insulin secretion, has heterogeneous clinical and laboratory features, and account for 1-5% of all diabetes cases. The prevalence and distribution of MODY subtypes vary between countries. The aim of this study was to evaluate the clinical and laboratory characteristics, mutation distribution, and phenotype-genotype relationship in a large case series of pediatric Turkish patients genetically diagnosed with MODY. Methods: MODY cases from 14 different pediatric endocrinology departments were included. Diagnosis, treatment, follow-up data, and results of genetic analysis were evaluated. Results: A total of 224 patients were included, of whom 101 (45%) were female, and the mean age at diagnosis was 9.4±4.1 years. Gene variant distribution was: 146 (65%) GCK; 43 (19%) HNF1A; 8 (3.6%) HNF4A, 8 (3.6%) KLF11 and 7 (3.1%) HNF1B. The remaining 12 variants were: PDX (n=1), NEUROD1 (n=3), CEL (n=1), INS (n=3), ABCC8 (n=3) and KJNC11 (n=1). Of the cases, 197 (87.9%) were diagnosed with incidental hyperglycemia, 16 with ketosis (7%) and 7 (3%) with diabetic ketoacidosis (DKA), while 30% presented with classical symptoms of diabetes. Two-hundred (89%) had a family history of diabetes. Anti-GAD antibody was detected in 13 cases, anti-islet antibody in eight and anti-insulin antibody in four. Obesity was present in 16. Distribution of therapy was: 158 (71%) diet only; 23 (11%) intensive insulin treatment; 17 (7.6%) sulfonylureas; 10 (4.5%) metformin; and 6 (2.7%) insulin and oral antidiabetic treatment. Conclusion: This was the largest genetically diagnosed series from Turkey. The most common gene variants were GCK and HNF1A with much lower proportions for other MODY types. Hyperglycemia was the most common presenting symptom while 11% of patients had diabetes-associated autoantibodies and 7% were obese. The majority of patients received dietary management only.

Investigation of the molecular genetic causes of non-syndromic primary ovarian insufficiency by next generation sequencing analysis.

Objective: The aim of this study is to investigate the molecular genetic causes of non-syndromic primary ovarian insufficiency (POI) cases with the gene panel basedon next generation sequencing analysis and to establish the relationship between genotype and phenotype. Materials and methods: Twenty three cases aged 14-40 years followed up with POI were included. Patients with a karyotype of 46, XX, primary or secondary amenorrhea before the age of 40, with elevated FSH (>40 IU/mL) and low AMH levels (<0.03 ng/mL) were included in the study. Molecular genetic analyzes were performed by the next generation sequencing analysis method targeted with the TruSight TM Exome panel. Results: Median age of the cases was 17.8 (14.0-24.3) years, and 12 (52%) cases admitted before the age of 18. Fifteen (65%) patients had consanguineous parents. In2 (8.6%) cases, variants detected were in genes that have been previously proven to cause POI. One was homozygous variant in FIGLA gene and the other was homozygous variant in PSMC3IP gene. Heterozygous variants were detected in PROK2, WDR11 and CHD7 associated with hypogonadotropic hypogonadism, but these variants are insufficient to contribute to the POI phenotype. Conclusion: Genetic panels based on next generation sequencing analysis technologies can be used to determine the molecular genetic diagnosis of POI, which has a highly heterogeneous genetic basis.

Systolic and diastolic left ventricular function in children with primary hypertension: a systematic review and meta-analysis.

OBJECTIVE: Evaluation of left ventricular function provides early evidence of target-organ damage in children with primary hypertension. We performed a systematic review and meta-analysis of left ventricular systolic and diastolic function in children and adolescents with primary hypertension. METHODS: Literature search was performed in PubMed database and out of 718 articles (published between 2000 and 2021) 22 studies providing comparison of left ventricular function parameters between children with primary hypertension and normotensive controls were selected. RESULTS: Overall, 3460 children (5-21 years) with primary hypertension were analyzed. Meta-analysis showed that hypertensive patients when compared with normotensives, had an increased heart rate (mean difference [MD] 5.59; 95% confidence interval [CI] 3.28, 7.89; 10 studies) and increased fractional shortening (MD 1.04; 95% CI 0.48, 1.60; 9 studies) but did not differ in ejection fraction (MD -0.03; 95% CI -1.07, 1.02; 12 studies). Stroke volume was higher in one out of three studies, whereas no differences in cardiac output were found in two studies with available data. Hypertensive children had also lower E/A values (MD -0.21; -0.33, -0.09; 14 studies), greater values of E/e' (MD 0.59; 0.36, 0.82; 8 studies) and greater global longitudinal stress (MD 2.50; 2.03, 2.96; 4 studies) when compared to those with normotension. CONCLUSION: Our results indicate that hypertensive children and adolescents present with signs of hyperkinetic function of the left ventricle, demonstrate evidence of increased left ventricular strain and impaired diastolic function compared to normotensive controls.

Knowledge gaps and future directions in cognitive functions in children and adolescents with primary arterial hypertension: A systematic review.

Arterial hypertension (AH) among adults is known to be associated with worse cognitive outcomes. Similarly, children and adolescents with AH could be expected to underperform during neuropsychological evaluations when compared with healthy peers. Our aims were to review the existing literature on cognitive functioning among children and adolescents with primary AH and to identify what additional evidence may be needed to substantiate the impact of hypertension on poor cognitive outcomes in this population. We conducted a systematic review of articles in PubMed and Web of Science published before 17 January 2022, reporting on cognitive testing among children and adolescents with primary AH. From 1,316 records, 13 were included in the review-7 used battery-testing while other employed indirect measures of cognitive functions. Most of the studies reported worse results among individuals with AH. Results of two prospective trials suggested that cognitive functioning may improve after starting antihypertensive treatment. Ambulatory blood pressure monitoring was shown to be more strongly related to cognitive testing results than office measures of blood pressure. Significant confounders, namely obesity and sleep apnea, were identified throughout the studies. Our review indicates that evidence relating AH with poor cognitive functioning among youth is usually based on indirect measures of executive functions (e.g., questionnaires) rather than objective neuropsychological tests. Future prospective trials set to test different cognitive domains in children and adolescents undergoing treatment for AH are endorsed and should consider using standardized neuropsychological batteries as well as adjust the assessing results for obesity and sleep disorders.

Clinical features of the diabetes eating problem survey-revised Turkish version in children and adolescent with type 1 diabetes.

Objectives We aim to delineate clinical characteristics that place individuals with type 1 diabetes (T1DM) at risk of developing eating problems by using Turkish version of diabetes eating problem survey-revised (DEPS-R). Methods The patients aged 9-18 years with T1DM who came to the pediatric endocrine outpatient clinic for control between February and December 2019 completed Turkish version of DEPS-R. Clinical and laboratory findings were obtained from patient files. Cases with a questionnaire score ≥20 were considered to be at risk for eating disorders (ED). Parents were informed when the results of the screening were positive, and were offered to child psychiatrist. Results The median scores obtained with the Turkish version of DEPS-R for the total sample, for females and males were 15, 16, and 13 respectively. The score was significantly higher among females compared to males (p<0.001). DEPS-R score positive group had higher age (mean [SD]=14.6 [2.7], p=0.009), BMI (mean [SD]=21.4 [3.2], p<0.001), HbA1c % (mean [SD]=9.37[2.3], p<0.001) and year of diabetes duration (mean [SD]=5.5 [3.6], p<0.001) compared to the negative group. Conclusions Early recognition and adequate treatment of ED in T1DM is essential. DEPS-R is sensitive in identifying young people with ED.

Evaluation of long-term follow-up and methimazole therapy outcomes of pediatric Graves' disease: a single-center experience.

Background The management options for Graves' disease in children are limited and there is controversy regarding optimal treatment. Remission rate with anti-thyroid drug (ATD) treatment in children is said to be lower than in adults. Definitive treatments are effective, but they often result in permanent hypothyroidism. The objective of this study was to investigate the outcome of methimazole treatment, identify significant predictors of a remission and evaluate the adverse effects of methimazole in a pediatric population of GD patients. Methods Medical records of the patients who had been diagnosed with Graves' disease were screened retrospectively. Diagnostic criteria included elevated free thyroxine (fT4) and total triiodothyronine (T3), suppressed thyroid-stimulating hormone (TSH) and either positive thyroid-stimulating immunoglobulin (TSI) or thyroid receptor antibodies (TRABs) or clinical signs suggestive of Graves' disease, for example, exophthalmos. Remission was defined as maintenance of euthyroidism for more than 12 months after discontinuing methimazole treatment. Results Of the 48 patients, provisional remission was achieved in 21 patients. Of the 21 patients, 14 experienced a relapse (66.6%). Remission was achieved in seven (24.1%) of 29 patients who received methimazole treatment for more than 2 years. In patients who achieved long-term remission, the male sex ratio and fT4 levels at diagnosis were significantly lower than the relapsed and non-remission groups, whereas the free triiodothyronine (fT3)/fT4 ratio and duration of methimazole treatment were significantly higher than the relapse group. Conclusions Long-term methimazole treatment in pediatric Graves' disease would be appropriate. High fT4 levels at the time of diagnosis and male sex were associated with a risk of relapse.

Management of Thyrotoxicosis in Children and Adolescents: A Turkish Multi-center Experience

Objective: To determine the demographic and biochemical features of childhood and juvenile thyrotoxicosis and treatment outcome. Methods: We reviewed the records of children from 22 centers in Turkey who were diagnosed with thyrotoxicosis between 2007 to 2017. Results: A total of 503 children had been diagnosed with thyrotoxicosis at the centers during the study period. Of these, 375 (74.6%) had been diagnosed with Graves' disease (GD), 75 (14.9%) with hashitoxicosis and 53 (10.5%) with other less common causes of thyrotoxicosis. The most common presenting features in children with GD or hashitoxicosis were tachycardia and/or palpitations, weight loss and excessive sweating. The cumulative remission rate was 17.6% in 370 patients with GD who had received anti-thyroid drugs (ATDs) for initial treatment. The median (range) treatment period was 22.8 (0.3-127) months. No variables predictive of achieving remission were identified. Twenty-seven received second-line treatment because of poor disease control and/or adverse events associated with ATDs. Total thyroidectomy was performed in 17 patients with no recurrence of thyrotoxicosis and all became hypothyroid. Ten patients received radioiodine and six became hypothyroid, one remained hyperthyroid and restarted ATDs and one patient achieved remission. Two patients were lost to follow up. Conclusion: This study has demonstrated that using ATDs is the generally accepted first-line approach and there seems to be low remission rate with ATDs in pediatric GD patients in Turkey.

Incidence of Type 1 Diabetes in Children Aged Below 18 Years during 2013-2015 in Northwest Turkey

Objective: To assess the incidence of type 1 diabetes mellitus (T1DM) in children under 18 years of age in the northwest region of Turkey during 2013-2015. Methods: All newly diagnosed T1DM cases were recorded prospectively during 2013-2015. Total, as well as gender and age group specific (0-4, 5-9, 10-14 and 15-17 age) mean incidences per 100,000 per year were calculated. Results: There were 1,773 patients diagnosed during 2013-2015 (588 cases in 2013, 592 cases in 2014, 593 cases in 2015). Of these, 862 (48.6%) were girls and 911 (51.4%) were boys. The mean age at diagnosis was 9.2±4.2 years and it was not significantly different between girls (9.0±4.1 years) and boys (9.4±4.4 years) (p=0.052). The crude mean incidence was 8.99/100.000 confidence interval (CI) (95% CI: 8.58-9.42). Although mean incidence was similar between boys [8.98/100.000 (CI: 8.40 to 9.58)] and girls [9.01/100.000 (CI: 8.42 to 9.63)], there was male predominance in all groups except for 5-9 year age group. The standardized mean incidence was 9.02/100.000 according to the World Health Organization standard population. The mean incidence for the 0-4, 5-9, 10-14 and 15-17 age groups was 6.13, 11.68, 11.7 and 5.04/100.000 respectively. The incidence of T1DM was similar over the course of three years (p=0.95). A significant increase in the proportion of cases diagnosed was observed in the autumn-winter seasons. Conclusion: The northwest region of Turkey experienced an intermediate incidence of T1DM over the period of the study.

Subclinical left ventricular systolic and diastolic dysfunction in type 1 diabetic children and adolescents with good metabolic control.

OBJECTIVE: Cardiac dysfunction is a well-known consequence of diabetes mellitus. This study was designed to assess whether type 1 diabetic children and adolescents with good metabolic control have early echocardiographic signs of subclinical left ventricular dysfunction and whether diabetes duration has any influence, using conventional and nonconventional echocardiographic tools. METHODS: A total of 100 patients with type 1 diabetes mellitus and 80 gender- and age-matched healthy controls were included. The cases underwent standard conventional transthoracic echocardiography, tissue Doppler imaging, and two-dimensional speckle tracking echocardiography. None of the diabetic patients had signs of renal, retinal, or neurological complications of the disease, and all were good metabolic control (mean HbA1c <7.5%). RESULTS: There was no difference among groups in relation to age, sex, body mass index, and blood pressure. Conventional echocardiographic parameters were similar between diabetic and nondiabetic subjects except increased mitral valve peak A-wave and significantly lower mitral E/A ratio in diabetics. Diabetic patients had more advanced diastolic dysfunction with TDI analysis. In the diabetic group, left ventricular global longitudinal, circumferential, and radial strain and strain rate were significantly lower compared with the controls. There was a positive correlation between diabetes duration and cardiac dysfunction. CONCLUSION: The results of this study showed that the diabetic children and adolescents with good metabolic control had diastolic dysfunction when assessed with either conventional or tissue Doppler echocardiography. Also diabetic patients had subclinical LV systolic dysfunction with a normal LVEF which can be detected with 2D speckle tracking echocardiography.

A Patient with Proopiomelanocortin Deficiency: An Increasingly Important Diagnosis to Make.

Proopiomelanocortin (POMC) deficiency is a rare monogenic disorder with early-onset obesity. Investigation of this entity have increased our insight into the important role of the leptin-melanocortin pathway in energy balance. Here, we present a patient with POMC deficiency due to a homozygous c.206delC mutation in the POMC gene. We discuss the pathogenesis of this condition with emphasis on the crosstalk between hypothalamic and peripheral signals in the development of obesity and the POMC-melanocortin 4 receptors system as a target for therapeutic intervention.

AMH levels in girls with various pubertal problems.

BACKGROUND: Anti-Müllerian hormone (AMH) is produced by granulosa cells surrounding follicles that have undergone recruitment from the primordial follicle pool but have not been selected for dominance (preantral and early antral follicles). In healthy girls, serum levels of AMH vary considerably between individuals. We aimed to evaluate the AMH level in girls with premature thelarche (PT) and central precocious puberty (CPP). METHODS: Girls with CPP (n=21), PT (n=24) and a control prepubertal group (n=22) were included in the study. RESULTS: AMH levels were significantly higher in the PT group than the prepubertal control group and similar to the CPP group. AMH levels in the CPP group were similar to the prepubertal control group. AMH levels showed a significant negative correlation with luteinizing hormone (LH), free testosterone and dehydroepiandrosterone sulphate (DHEAS) levels in the PT group. AMH levels were negatively correlated with height standard deviation score (HSDS), body mass index (BMI) SDS values and positively correlated with sex hormone binding globulin (SHBG) levels in the CPP group. These levels were positively correlated with SHBG levels in the control prepubertal group. CONCLUSIONS: Serum AMH levels in girls with PT was found to be higher than in prepubertal girls. AMH levels in the CPP group were not different compared with the PT and control groups.

Treatment experience and long-term follow-up data in two severe neonatal hyperparathyroidism cases.

The calcium sensing receptor (CASR) is expressed most abundantly in the parathyroid glands and the kidney. CASR regulates calcium homeostasis through its ability to modulate parathormone secretion and renal calcium reabsorption. Inactivating mutations in the CASR gene may result in disorders of calcium homeostasis manifesting as familial benign hypocalciuric hypercalcemia (FBHH) and neonatal severe hyperparathyroidsm (NSHPT). Two cases were referred with severe hypercalcemia in the neonatal period. Laboratory evaluation revealed severe hypercalcemia and elevated PTH. The parents also had mild hypercalcemia. The serum calcium level did not normalize with conventional hypercalcemia treatment and there was also no response to cinacalcet in case 1. Total parathyroidectomy was performed when the patient was 70 days old. Genetic analysis revealed a novel homozygous p.Arg544* mutation in the CASR gene. Case 2 underwent total parathyroidectomy and autoimplantation when she was 97 days old, but the parathyroid gland implanted into the forearm was removed 27 days later because the hypercalcemia continued. Genetic evaluation revealed a novel homozygous p.Pro682Leu mutation with normal anthropometric measurements. The neurological development is consistent with age in both cases while case 2 has mild mental retardation. No bone deformity or fracture is present in either case and normocalcemia is ensured with calcitriol in both cases.

Do the Anti-Müllerian Hormone Levels of Adolescents with Polycystic Ovary Syndrome, Those Who Are at Risk for Developing Polycystic Ovary Syndrome, and Those Who Exhibit Isolated Oligomenorrhea Differ from Those of Adolescents with Normal Menstrual Cycles?

BACKGROUND/AIMS: We aimed to investigate whether the anti-Müllerian hormone (AMH) levels in adolescents with polycystic ovary syndrome (PCOS), PCOS risk, and isolated oligomenorrhea (OM) were different than in adolescents with a normal/regular menstrual cycle (NMC). METHODS: The diagnosis of PCOS was based on the 2012 Amsterdam [European Society of Human Reproduction and Embryology/American Society for Reproductive Medicine (ESHRE/ASRM)] criteria. The PCOS group consisted of cases meeting 3 diagnostic criteria (n = 21), and the PCOS risk group was the 'at risk' group meeting 2 diagnostic criteria (n = 20). Cases with isolated OM that did not satisfy other PCOS diagnostic criteria made up the OM group (n = 21). Thirty adolescent girls with NMCs (21-45 days) were recruited in this study. RESULTS: The AMH levels in the PCOS group were similar to those in the PCOS risk group but significantly higher than those in the OM and NMC groups. The AMH levels in the PCOS risk group were similar to those in the OM group and significantly higher than those in the NMC group. They were also significantly higher in the OM group compared to the NMC group. The specificity for PCOS and PCOS risk with a cutoff value of 7.25 ng/ml for AMH was 72.5% and the sensitivity was 58%. CONCLUSION: An AMH cutoff value of 7.25 ng/ml can be used for the diagnosis of PCOS in the adolescent period.

Comparison of anterior segment parameters in juvenile diabetes mellitus and healthy eyes.

PURPOSE: To compare the anterior segment parameters of patients with juvenile diabetes mellitus (DM) and healthy children by optical biometry. METHODS: This prospective controlled clinical trial included 47 patients with juvenile type 1 DM and 50 age- and sex-matched healthy children. Central corneal thickness (CCT), aqueous depth (AD), lens thickness (LT), axial length, pupillary diameter (PD), K1 and K2 keratometry, and white to white distance (WTW) measurements were performed with optical biometry. The glycosylated hemoglobin (HbA1c) levels of the DM cases were obtained. Kolmogorov-Smirnov test, t test, χ2 test, and Pearson correlation test were used for statistical analysis. RESULTS: The mean age of the 20 boys and 27 girls with DM was 10.91 ± 3.24 years and the mean age of the 29 healthy boys and 21 girls was 11.61 ± 3.6 years (age p = 0.42; sex p = 0.09). The mean LT was thicker (p = 0.001), the mean AD was lower (p = 0.001), and the mean PD was smaller (p = 0.001) in the DM cases and all were statistically significant. There was no significant difference between the groups for AU, CCT, WTW, or K1 and K2 (p = 0.12; p = 0.83; p = 0.54; p = 0.97; p = 0.21, respectively). We also found a significant negative correlation between HbA1c levels and PD (r = -0.37 p = 0.01). CONCLUSIONS: Juvenile DM may affect anterior segment parameters and cause thicker LT, smaller PD, and lower AD. These effects may change the refractive status and should be considered during the examination of these children.

The evaluation of transient hypothyroidism in patients diagnosed with congenital hypothyroidism.

BACKGROUND/AIM: Congenital hypothyroidism (CH) is divided into two groups as 'permanent' and 'transient' We aimed to determine the rate of transient and permanent congenital hypothyroidism of the newborns referred to our clinic. MATERIALS AND METHODS: Of the newborns who were referred to our clinic from the neonatal screening program, those who were diagnosed with CH and started treatment were included in the study. The treatments of the patients whose required daily treatment dose was reduced to under 1 µg/kg were terminated and those who were followed monthly and whose fT4 and thyroid-stimulating hormone (TSH) levels were normal at least 3 times without treatment were considered to have transient hypothyroidism. RESULTS: Of the 256 newborns referred to our clinic from the neonatal screening program, 114 (44.5%) were diagnosed with CH. Of the CH patients, 70% (n = 58) were evaluated to have permanent and 30% (n = 25) transient hypothyroidism. Neonatal and serum TSH levels and treatment doses were found to be significantly lower in the transient hypothyroidism patients. CONCLUSION: Initial measurements of the serum TSH level and the required doses of L-thyroxine therapy for maintaining normal thyroid hormone levels, growth, and development may have a predictive role for differentiating permanent forms of CH from transient forms.

Risk factors affecting the development of nephrocalcinosis, the most common complication of hypophosphatemic rickets.

The aim of the present study was to analyse the effects of combined treatment with calcitriol and phosphate, to find out the incidence of the nephrocalcinosis, and to elucidate the risk factor of nephrocalcinosis in patients with hypophosphatemic rickets. We followed six patients. The median age at diagnosis was 3.25 (0.75-10.5) years. The median follow-up duration was 8.25 (3.5-12.5) years. The mean dose of calcitriol and phosphate treatments was 39.1±8 ng/kg/day, 90.5±57.1 mg/kg/day, respectively. Nephrocalcinosis was detected in three patients (50%). The mean dose of phosphate taken by the patients found to have nephrocalcinosis was detected to be high with a statistically significant difference (p=0.041). No significant relationship was found the mean dose of calcitriol. We found no relationship between the development of nephrocalcinosis and the incidence of hypercalciuria or hypercalcemia episodes. We found the increased phosphate dose administered for treatment to play a role in nephrocalcinosis development.