A Very-Low-Calorie Diet Can Cause Remission of Diabetes Mellitus and Hypertriglyceridemia in Familial Partial Lipodystrophy.

There is no strong evidence that any specific diet is the preferred treatment for lipodystrophy syndromes. Here we remark on the benefits of a very-low-calorie diet (VLCD) in a patient with familial partial lipodystrophy type 2 (FPLD2). A 38-year-old female diagnosed with FPLD2, with a history of multiple comorbidities, underwent 16 weeks of VLCD with a short-term goal of improving her metabolic state rapidly to achieve pregnancy by in vitro fertilization (IVF). We observed a reduction of 12.3 kg in body weight and 1.4% in hemoglobin A1c. The decrease in the area under the curves of insulin (-33.2%), triglycerides (-40.7%), and free fatty acids (-34%) were very remarkable. Total body fat was reduced by 16%, and liver fat by 80%. Her egg retrieval rate and quality during IVF were far superior to past hyperstimulation. Our data encourage the use of this medical approach for other patients with similar metabolic and reproductive abnormalities due to adipose tissue insufficiency.

Deciphering the Clinical Presentations in LMNA-related Lipodystrophy: Report of 115 Cases and a Systematic Review.

CONTEXT: Lipodystrophy syndromes are a heterogeneous group of rare genetic or acquired disorders characterized by generalized or partial loss of adipose tissue. LMNA-related lipodystrophy syndromes are classified based on the severity and distribution of adipose tissue loss. OBJECTIVE: We aimed to annotate all clinical and metabolic features of patients with lipodystrophy syndromes carrying pathogenic LMNA variants and assess potential genotype-phenotype relationships. METHODS: We retrospectively reviewed and analyzed all our cases (n = 115) and all published cases (n = 379) curated from 94 studies in the literature. RESULTS: The study included 494 patients. The most common variants in our study, R482Q and R482W, were associated with similar metabolic characteristics and complications though those with the R482W variant were younger (aged 33 [24] years vs 44 [25] years; P < .001), had an earlier diabetes diagnosis (aged 27 [18] vs 40 [17] years; P < .001) and had lower body mass index levels (24 [5] vs 25 [4]; P = .037). Dyslipidemia was the earliest biochemical evidence described in 83% of all patients at a median age of 26 (10) years, while diabetes was reported in 61% of cases. Among 39 patients with an episode of acute pancreatitis, the median age at acute pancreatitis diagnosis was 20 (17) years. Patients who were reported to have diabetes had 3.2 times, while those with hypertriglyceridemia had 12.0 times, the odds of having pancreatitis compared to those who did not. CONCLUSION: This study reports the largest number of patients with LMNA-related lipodystrophy syndromes to date. Our report helps to quantify the prevalence of the known and rare complications associated with different phenotypes and serves as a comprehensive catalog of all known cases.

Aromatase Inhibitors May Increase the Risk of Cardiometabolic Complications in Adolescent Boys.

INTRODUCTION: Aromatase inhibitors (AIs) are increasingly used in children and adolescents to augment adult height. The aim of this study was to investigate the effects AIs have on cardiac morphology, functions and their relation to several metabolic parameters in adolescent boys. METHODS: Three groups matched for sex (boys, n = 67), age (median age 13.5 years), weight, height, body mass index, and puberty stages were enrolled: (i) Group 1: 23 patients using AIs (only AI (n = 6) or in combination with growth hormone (GH) (n = 17)) for at least 6 months; (ii) Group 2: 22 patients using only GH, and (iii) Group 3: 22 healthy boys. Two-dimensional, M-mode conventional Doppler and tissue Doppler examinations of the left ventricle (LV) were performed. Bioelectrical bioimpedance analyses was conducted and follicle-stimulating hormone, luteinizing hormone, total testosterone, lipid, and hemogram parameters were obtained. RESULTS: Patients in Group 1 had significantly higher serum total testosterone (p < 0.001) and hemoglobin (p < 0.001) levels, fat free mass (p = 0.005), LV mass (LVM) (p = 0.002), as well as increased LV posterior wall diameter (LVPWD) (p = 0.002), interventricular septum diameter (IVSD) (p = 0.019), and myocardial systolic wave velocity (Sm) (p = 0.020) compared to the two other control groups. No significant differences were observed in terms of diastolic and systolic functions and lipid profiles (p > 0.05). There were positive correlations between total testosterone, hemoglobin levels, LVM, LVPWD and IVSD (p < 0.05). CONCLUSION: Increased LVM, LVPWD, IVSD and Sm of patients receiving AI therapy in comparison to the control groups, and the significant correlations of these parameters with total testosterone and hemoglobin levels were determined as potential side effects of AIs. These findings emphasize the need of routine cardiac follow-up in patients using AIs.

Clinical Characteristics of Children with Combined Pituitary Hormone Deficiency and the Effects of Growth Hormone Treatment.

AIM: We aimed to describe the clinical characteristics of patients with congenital combined pituitary hormone deficiency (CPHD) and evaluate the first-year growth responses of individuals with CPHD and isolated growth hormone deficiency (IGHD) in order to establish the influence of other hormone deficiencies on growth response. PATIENTS AND METHODS: This retrospective study was conducted in four tertiary care centers in Turkey. The records of patients diagnosed with CPHD (n=39) and severe IGHD (n=50) were collected. Cases with acquired lesions or chronic diseases were not included in the study. Data are presented as median (interquartile range). RESULTS: Among 39 patients (13 females; 33%) with a diagnosis of CPHD, the majority of patients (64%) presented initially with combined deficits at baseline examination, whereas isolated deficiencies (36%) were less prevalent. Among all patients with GH deficiency, TSH, ACTH, FSH/LH, and ADH deficiencies were present in 94%, 74%, 44%, and 9% of patients, respectively. Patients with CPHD were diagnosed at a younger age (4.9 (8.4) vs. 11.6 (4.1), p<0.001, respectively) and had lower peak GH concentrations (0.4 (1.8) vs. 3.7 (2.9), p<0.001, respectively) than patients with IGHD. Patients with IGHD and CPHD had similar first-year growth responses (Δheight SD score of 0.55 (0.63) vs. 0.76 (0.71), respectively, p=0.45). CONCLUSIONS: We established the nature and timing of numerous hormonal deficits emerging over time. We also identified that the existence of CPHD did not hinder growth response.

Atypical Presentation and Course of ACTH-independent Cushing's Syndrome in Two Families.

Primary pigmented nodular adrenocortical disease (PPNAD) is a rare genetic disease mainly associated with Carney complex (CNC), which is caused by germline mutations of the regulatory subunit type 1A (RIα) of the cAMP-dependent protein kinase (PRKAR1A) gene. We report three cases suffering from CNC with unique features in diagnosis and follow-up. All cases had obesity and a cushingoid appearance and exhibited laboratory characteristics of hypercortisolism. However biochemical and radiological examinations initially suggested Cushing's disease in one case . All of the cases were treated surgically; two of them underwent bilateral adrenalectomy at once, one of them had unilateral adrenalectomy at first but required contralateral adrenalectomy after nine months. Contrary to what is usually known regarding PPNAD, the adrenal glands of two cases (case 2 and 3) had a macronodular morphology. Genetic analyses revealed pathogenic variants in PRKAR1A (case 1: c.440+5 G>A, not reported in the literature; cases 2 and 3: c.349G>T, p.V117F). One case developed Hodgkin lymphoma five year after adrenalectomy, this association was not previously reported with CNC. The findings of these families provide important information for a better understanding of the genetic pathogenesis, diagnosis, and clinical management of CNC. Hodgkin lymphoma may be a component of CNC.

Which method is more effective in predicting adult height in pubertal girls treated with gonadotropin-releasing hormone agonist?

PURPOSE: The aim of the present study was to determine the efficiency of three different predictive models [Bayley-Pinneau (BP), Roche-Wainer-Thissen (RWT), and Tanner-Whitehouse 2 (TW2)] by comparing their predictions with near-adult height data of girls receiving gonadotropin-releasing hormone agonist (GnRHa) therapy. METHODS: Clinical findings were retrospectively analyzed. Bone ages obtained before treatment were evaluated from left hand and wrist radiographs by three researchers. Predicted adult height (PAH) was calculated using the BP, RWT, and TW2 methods for each patient at the beginning of therapy. RESULTS: The median age at diagnosis of the 48 patients included in the study was 8.8 (8.9-9.3) years. There was no significant difference between the mean bone ages evaluated separately with the Greulich-Pyle atlas and the TW3-RUS method (p=0.34). Among the PAH methods, only PAH measured by the BP method was very close to and no different from near adult height (NAH) [159.8±6.3 vs. 158.8±9.3 cm. p=0.3; (-0.5±1.1) vs. (-0.7±1.6) standard deviation score, p=0.1]. Accordingly, the BP method was found to be the most accurate prediction tool in girls with puberty treated with GnRHa. CONCLUSION: The BP method is more effective at predicting adult height than the RWT and TW2 methods in female patients who will receive GnRHa treatment.

Adverse Events Associated with COVID-19 Vaccination in Adolescents with Endocrinological Disorders: A Cross-Sectional Study

Objective: The aim was to evaluate the adverse events seen after Coronavirus disease-2019 (COVID-19) vaccination in pediatric patients with diagnosed endocrinological problems and to compare them with healthy controls. Methods: In this cross-sectional study, patients aged 12-18 years who attended a single department between January and May 2022 and were followed up for at least six months due to endocrine diseases, and healthy subjects in the same age group, all of whom had received a COVID-19 vaccine [BNT162b2 mRNA or inactivated vaccine] were included. Adverse events experienced after the vaccination were evaluated by questionnaire. Results: A total of 160 subjects (85 patients, 75 healthy controls) with a median (25-75p) age of 15.5 (14.1-16.9) years were included. The frequency of adverse events was higher in those vaccinated with the mRNA vaccine compared to the inactivated one after the first dose (p=0.015). The incidence of adverse events observed after the first and second doses of both COVID-19 vaccines was similar in the patient and control groups (p=0.879 and p=0.495, respectively), with local reactions being the most common. The frequency of adverse events was similar among the patients who did or did not receive any endocrinological treatment (p>0.05). The incidence and severity of systemic reactions were similar to those in healthy subjects for both vaccine doses, regardless of the underlying diagnosis, autoimmunity state, or treatment regimen used in patients with endocrine diseases. Conclusion: The incidence and severity of adverse events associated with COVID-19 vaccinations in adolescents with endocrinological disorders were similar to healthy subjects, in the early post-vaccination period.

Growth Hormone Dosing Estimations Based on Body Weight Versus Body Surface Area

Objective: Both body weight (BW)- and body surface area (BSA)-based dosing regimens have been recommended for growth hormone (rhGH) replacement. The aim was to compare the two regimens to determine if either resulted in inadequate treatment depending on anthropometric factors. Methods: The retrospective study included children diagnosed with idiopathic isolated growth hormone deficiency. BW-based dosing in mcg/kg/day was converted to BSA in mg/m2/day to determine the equivalent amounts of the given rhGH. Those with a BW-to-BSA ratio of more than 1 were allocated to the "relatively over-dosed group", while the remaining patients with a ratio of less than 1 were assigned to the "relatively under-dosed" group. Patients with a height gain greater than 0.5 standard deviation score (SDS) at the end of one year were classified as the height gain at goal (HAG), whereas those with a height gain of less than 0.5 SDS were assigned as the height gain not at goal (NHAG). Results: The study included 60 patients (18 girls, 30%). Thirty-six (60%) patients were classified as HAG. The ratio of dosing based on BW-to-BSA was positively correlated both with the ages and body mass index (BMI) levels of the patients, leveling off at the age of 11 at a BMI of 18 kg/m2. The relative dose estimations (over- and under-dosed groups) differed significantly between the patients classified as HAG or NHAG. Fifty-six percent of NHAG compared to 44% of HAG patients received relatively higher doses, while 79% of HAG compared to 21% of NHAG received relatively lower doses (p=0.006). When the patients were subdivided according to their pubertal status, higher doses were administrated mostly to the pubertal patients in both the NHAG and HAG groups. In the pre-pubertal age group, 73% of NHAG compared to 27% of HAG received relatively higher doses, while 25% of NHAG compared to 75% of HAG received relatively lower doses (p=0.01). Conclusion: Dosing based on BW may be preferable in both prepubertal and pubertal children who do not show adequate growth responses. In prepubertal children, relatively lower doses calculated based on BW rather than BSA provide similar efficacy at lower costs.

A National Multicenter Study of Leptin and Leptin Receptor Deficiency and Systematic Review.

CONTEXT: Homozygous leptin (LEP) and leptin receptor (LEPR) variants lead to childhood-onset obesity. OBJECTIVE: To present new cases with LEP and LEPR deficiency, report the long-term follow-up of previously described patients, and to define, based on all reported cases in literature, genotype-phenotype relationships. METHODS: Our cohort included 18 patients (LEP = 11, LEPR = 7), 8 of whom had been previously reported. A systematic literature review was conducted in July 2022. Forty-two of 47 studies on LEP/LEPR were selected. RESULTS: Of 10 new cases, 2 novel pathogenic variants were identified in LEP (c.16delC) and LEPR (c.40 + 5G > C). Eleven patients with LEP deficiency received metreleptin, 4 of whom had been treated for over 20 years. One patient developed loss of efficacy associated with neutralizing antibody development. Of 152 patients, including 134 cases from the literature review in addition to our cases, frameshift variants were the most common (48%) in LEP and missense variants (35%) in LEPR. Patients with LEP deficiency were diagnosed at a younger age [3 (9) vs 7 (13) years, P = .02] and had a higher median body mass index (BMI) SD score [3.1 (2) vs 2.8 (1) kg/m2, P = 0.02], which was more closely associated with frameshift variants (P = .02). Patients with LEP deficiency were more likely to have hyperinsulinemia (P = .02). CONCLUSION: Frameshift variants were more common in patients with LEP deficiency whereas missense variants were more common in LEPR deficiency. Patients with LEP deficiency were identified at younger ages, had higher BMI SD scores, and had higher rates of hyperinsulinemia than patients with LEPR deficiency. Eleven patients benefitted from long-term metreleptin, with 1 losing efficacy due to neutralizing antibodies.

Clinical course of primary empty sella in children: a singlecenter experience.

BACKGROUND: Various studies, mainly conducted in adults, have examined the hormonal axis in primary empty sella (PES), and reported various forms of pituitary deficiencies. We report our experience with PES in pediatric patients in terms of pituitary function, associated impairments, and responses to treatment. METHODS: We reviewed 10,560 cranial and 325 pituitary magnetic resonance imagings (MRIs) performed at our university hospital between January 2010 and December 2020 and identified patients with PES. Patients with additional abnormal MRI findings, a history of cranial surgery or radiotherapy, autoimmunity, long-term use of chemotherapeutic or immunosuppressive agents or incomplete diagnostic evaluation were excluded. Clinical, radiological and laboratory evaluations were recorded. RESULTS: The study included 17 patients [9 girls, 8 boys; median age 12.4 years (7.25, 4.3 - 17)]. The median size of the pituitary was 2 mm (0.7, 1.2 - 3). Based on age-dependent pituitary height measurements, fifteen (88%) patients had pituitary gland hypoplasia. Five patients presented with short stature, two had both pubertal delay and short stature, and one had pubertal delay. Nine patients presented with neurological symptoms such as headaches, tinnitus, tics, and dizziness. Five short patients had growth hormone deficiency. None of the patients had hyper- or hypoprolactinemia, adrenal insufficiency, hypothyroidism, or diabetes insipidus. There was statistically no significant association between the size of the pituitary gland and the severity of hypopituitarism (p = 0.42). CONCLUSIONS: The high incidence of pituitary dysfunctions ascertain that this entity should not be considered a normal variant but, should instead be carefully evaluated with appropriate basal and dynamic hormonal testing.

Efficacy of aromatase inhibitor therapy in a case with large cell calcifying Sertoli cell tumour-associated prepubertal gynaecomastia.

OBJECTIVES: Large cell calcifying Sertoli cell tumours (LCCSCTs) are one of the infrequent causes of prepubertal gynaecomastia. Most of these tumours are in the content of Peutz-Jeghers syndrome (PJS) or other familial syndromes (Carney complex). CASE PRESENTATION: Here, we report a long-term follow-up of an 8.5-year-old prepubertal boy with a diagnosis of PJS, who presented with bilateral gynaecomastia, advanced bone age and accelerated growth velocity, and were found to have bilateral multifocal testicular microcalcifications. As the findings were compatible with LCCSCT, anastrozole was initiated. Gynaecomastia completely regressed and growth velocity and pubertal development were appropriate for age during follow-up. Testicular lesions slightly increased in size. After four years of medication, anastrozole was discontinued but was restarted due to the recurrence of gynaecomastia after six months. CONCLUSIONS: Testicular tumour should be investigated in a patient with PJS who presents with prepubertal gynaecomastia. When findings are consistent with LCCSCT, aromatase inhibitors may be preferred in the treatment.

Biochemical indicators of euthyroid sick syndrome in critically ill children.

OBJECTIVES: This study aimed to determine the prevalence and predictors of euthyroid sick syndrome (ESS) in pediatric intensive care, and to establish a link between thyroid function tests and mortality. METHODS: Between January 2015 and March 2020, children admitted to our pediatric intensive care unit (PICU) and tested for free triiodothyronine (fT3), free thyroxine (fT4), and thyrotropin (TSH) levels were included. Patients with decreased fT3, with normal or decreased fT4, and normal or decreased TSH levels were assigned to the ESS group. The association between biochemical indicators and ESS, as well as the relationship between fT3 and mortality, were examined. RESULTS: A total of 141 (36%) of 386 children included to study were classified in the ESS group. The ESS group had a higher rate of 28-day mortality (12 [8.5%] vs. 9 [3.7%]). Blood urea nitrogen (BUN), albumin, platelet, lactate, and pediatric index of mortality 3 [PIM3 (%)] were significantly associated with ESS (odds ratios in order: 1.024, 0.422, 0.729, 1.208, 1.013). Multivariate regression analysis showed that BUN, albumin, platelet, and lactate were independently associated with ESS progression. The area under curve (AUC [95%CI]) for fT3 was 0.644 (0.555-0.789) to detect mortality. Children with a fT3 level lower than 2.31 pg/mL had significantly higher 28-day mortality (log rank test, p=0.001). CONCLUSIONS: Our study identified BUN, albumin, lactate, and platelet count as independent risk factors for ESS progression in children. Furthermore, our findings indicated a correlation between fT3 and mortality, which makes fT3 an ideal candidate to be included in mortality indices.

Has the Frequency of Precocious Puberty and Rapidly Progressive Early Puberty Increased in Girls During the COVID-19 Pandemic?

Objective: Early puberty is development of secondary sex characteristics earlier than the expected normal age range. We subjectively observed an increased frequency of early puberty during the Coronavirus disease-2019 (COVID-19) lockdown and aimed to show the clinical, demographic characteristics of the cases and the change in its incidence. Methods: Female patients with central precocious puberty (CPP, n=28) and rapidly progressive early puberty (RPEP, n=61), presenting to our clinic before (January 2019-March 2020) and during the COVID-19 pandemic (April 2020-June 2021) were included. Results: Among 28 CPP cases, six (21%) presented before the pandemic lockdown, whereas 22 (79%) were diagnosed during the COVID-19 pandemic lockdown. While RPEP was seen in 16 (26%) patients before the pandemic, 45 (74%) patients were diagnosed during the lockdown period. Presentation with menarche was seen in 15 RPEP patients; two (13%) were in the prepandemic period and 13 (87%) were in the lockdown period. Chronological age, bone age, bone age to chronological age ratio, height, weight, and body mass index standard deviation scores of patients with RPEP and CPP were similar between the prepandemic and pandemic period. Conclusion: In this cohort, the frequency of CPP and RPP cases were significantly (p<0.001) increased during the COVID-19 pandemic, possibly due to environmental changes.

Atypical comorbidities in a child considered to have type 1 diabetes led to the diagnosis of SLC29A3 spectrum disorder.

INTRODUCTION: SLC29A3 spectrum disorder is an autosomal, recessively inherited, autoinflammatory, multisystem disorder characterized by distinctive cutaneous features, including hyperpigmentation or hypertrichosis, hepatosplenomegaly, hearing loss, cardiac anomalies, hypogonadism, short stature, and insulin-dependent diabetes. CASE PRESENTATION: Herein, we report a 6-year-old boy who presented with features resembling type 1 diabetes mellitus, but his clinical course was complicated by IgA nephropathy, pure red cell aplasia, and recurrent febrile episodes. The patient was tested for the presence of pathogenic variants in 53 genes related to monogenic diabetes and found to be compound heterozygous for two SLC29A3 pathogenic variants (p. Arg386Gln and p. Leu298fs). CONCLUSION: This case demonstrated that SLC29A3 spectrum disorder should be included in the differential diagnosis of diabetes with atypical comorbidities, even when the distinctive dermatological hallmarks of SLC29A3 spectrum disorder are entirely absent.

Initial neutrophil/lymphocyte and lymphocyte/monocyte ratios can predict future insulin need in newly diagnosed type 1 diabetes mellitus.

OBJECTIVES: The exact mechanism of partial clinical remission in type 1 diabetes mellitus (T1DM) has not been elucidated yet. The severity of the inflammation at the time of diagnosis may affect the occurrence or duration of this phase. We aimed to investigate the relationship between hematological inflammatory parameters at the time of diagnosis in T1DM and (i) daily insulin requirement during the follow-up and (ii) the presence of partial clinical remission period, which was determined according to insulin dose-adjusted HbA1c levels. METHODS: A single-center retrospective study was conducted, including children who were diagnosed with T1DM, were positive for at least one autoantibody, and were followed up for one year in our clinic between 2010 and 2020. RESULTS: Sixty-eight patients (55.9% female, 64.7% prepubertal) were included in the study, whose mean age was 8.4 ± 4.2 years. A total of 38 patients (55.9%) had partial clinical remission. None of the initial hematological indices were associated with the occurrence of partial remission. Initial neutrophil/lymphocyte ratio (NLR) and derived-NLR (d-NLR) levels were significantly lower (p=0.011 and 0.033, respectively) and lymphocyte/monocyte ratio (LMR) levels were significantly higher (p=0.005) in patients who showed an insulin requirement of <0.5 IU/kg/day at the 3rd month after diagnosis. CONCLUSIONS: Initial hematological parameters were not found as a predictor of partial clinical remission period in T1DM in children. However, a lower NLR and d-NLR, or a higher LMR at the time of diagnosis can be used as an indicator of a low daily insulin need at the 3rd month of T1DM.

A 4-hour Profile of 17-hydroxyprogesterone in Salt-wasting Congenital Adrenal Hyperplasia: Is the Serial Monitoring Strategy Worth the Effort?

Objective: Since there is no gold standard laboratory variable for adjustment of treatment in congenital adrenal hyperplasia (CAH), the aim was to assess the use of a 4-hour profile of serum 17-hydroxyprogesterone (17-OHP) to determine the most appropriate sample time and level of 17-OHP in predicting the metabolic control and evaluate the role of sex hormone-binding globulin (SHBG) in hyperandrogenemia. Methods: This study included children with salt-wasting CAH. Measurements for 17-OHP and cortisol were made from samples obtained before and 1, 2, and 4 hours after the morning dose of hydrocortisone. Patients were designated to have poor metabolic control when androstenedione levels according to age and sex-specific reference intervals were high and annual height standard deviation score (SDS) changes were ≥0.5. Results: The study cohort was 16 children (9 girls) with a median age of 7-years old. Premedication 17-OHP levels were strongly correlated with 17-OHP levels 1, 2, and 4 hours after the morning dose (rs=0.929, p<0.01; rs=0.943, p<0.01; rs=0.835, p<0.01, respectively). 17-OHP profiles (0, 1, 2, 4 hours) of poor (n=6) and good (n=10) metabolically controlled cases were similar. Among the patients with poor metabolic control, two cases had 17-OHP levels <2 ng/mL at all times. The remaining patients with poor metabolic control had median 17-OHP levels above 104 ng/mL, 82 ng/mL, 14 ng/mL, and 4 ng/mL, for baseline and 1, 2, and 4 hours, respectively. Differences between the poor and well-controlled group were androstenedione levels with respect to upper limit of normal [1.8 (1.5) and 0.5 (1.5) ng/mL, respectively p=0.03], annual change in height SDS [0.7 (0.2) and -0.03 (0.8) SDS, respectively, p=0.001], and daily hydrocortisone doses [7 (6) and 16 (8) mg/m2/day, respectively, p=0.02]. Androstenedione and SHBG levels were negatively correlated in the pubertal children (rs=-0.7, p=0.04). Conclusion: We conclude that: (i) a 4-hour 17-OHP profile is not useful in predicting hyperandrogenemia; (ii) suppressed levels of 17-OHP do not always indicate overtreatment; (iii) reference intervals of 17-OHP for different time periods might be of importance; (iv) low hydrocortisone doses should be avoided; and (v) SHBG could be used in pubertal children as an indicator of hyperandrogenemia.

Reference values for T and B lymphocyte subpopulations in Turkish children and adults

Background/aim: Established reference values are critical for the interpretation of immunologic assessments. In particular, the proportion and absolute counts of T- and B- cell subpopulations are subject to change with age and ethnicity. We aimed to establish age- specific reference values for lymphocyte subsets using updated immunophenotyping panels. Materials and methods: We studied a total of 297 healthy Turkish subjects aged 0 to 50 years, stratified into major age brackets in a cluster factor of 10 per age-group. The predetermined age intervals contained randomly allocated participants enrolled over a period of 6 months, who were homogenously distributed by sex. We analyzed a complete blood count test and simultaneously with detailed immunophenotyping enumerated the percent and absolute cell counts of lymphocyte subsets. Results: The percentage and absolute counts of lymphocyte subsets show a marked surge across the age-span. T helper, T cytotoxic, and the natural killer cell numbers were increasing from birth until 6 months, followed by a gradual decrease thereafter. B cell numbers were rising until 2 years, followed by a gradual decrease for the upcoming years, accompanied by a steady expansion of unclass-switched- and class-switched- B cells. Conclusion: We provide updated extensive reference intervals for lymphocyte subpopulations in Turkish people.

Transcobalamin II deficiency in twins with a novel variant in the TCN2 gene: case report and review of literature.

Objectives Transcobalamin II (TC) is an essential plasma protein for the absorption, transportation, and cellular uptake of cobalamin. TC deficiency presents in the first year of life with failure to thrive, hypotonia, lethargy, diarrhea, pallor, mucosal ulceration, anemia, pancytopenia, and agammaglobulinemia. Herein, we present TC deficiency diagnosed in two cases (twin siblings) with a novel variant in the TCN2 gene. Case presentation 4-month-old twins were admitted with fever, respiratory distress, vomiting, diarrhea, and failure to thrive. Physical examination findings revealed developmental delay and hypotonia with no head control, and laboratory findings were severe anemia, neutropenia, and hypogammaglobulinemia. Despite normal vitamin B12 and folate levels, homocysteine and urine methylmalonic acid levels were elevated in both patients. Bone marrow examinations revealed hypocellular bone marrow in both cases. The patients had novel pathogenic homozygous c.241C>T (p.Gln81Ter) variant in the TCN2 gene. In both cases, with intramuscular hydroxycobalamin therapy, laboratory parameters improved, and a successful clinical response was achieved. Conclusions In infants with pancytopenia, growth retardation, gastrointestinal manifestations, and immunodeficiency, the inborn error of cobalamin metabolism should be kept in mind. Early diagnosis and treatment are crucial for better clinical outcomes. What is new? In literature, to date, less than 50 cases with TC deficiency were identified. In this report, we presented twins with TCN2 gene mutation. Both patients emphasized that early and aggressive treatment is crucial for achieving optimal outcomes. In this report, we identified a novel variation in TCN2 gene.