Volume 31, Issue 3

Hypovitaminosis D in childhood is a re-emerging public health problem in developed countries. New life style habits, current “epidemics” of obesity in children and adolescents worldwide, and other preventable risk factors may play a role in favoring the occurrence of vitamin D deficiency. In addition to skeletal consequences, hypovitaminosis D has been found to be involved in the development of serious health extra-skeletal problems in childhood, including atopy and autoimmunity. The increasing concerns about the global health impact of vitamin D deficiency make further research necessary to fill the gaps of knowledge in this field, and particularly to establish universally accepted “normal” serum 25(OH)D levels in the pediatric population, and to improve strategies for the screening, prevention and treatment of hypovitaminosis D. This review discusses the key points of hypovitaminosis D in childhood in the light of new knowledge, and highlights the limitations of current strategies to control this condition.

Background: Adults with type 2 diabetes (T2D) have significantly lower gray matter volume (GMV) compared to healthy peers. Whether GMV differences exist in youth with T2D remains unclear. Thus, we compared global and regional GMV between obese youth with T2D with age, race and sex similar healthy controls. Methods: In a cross-sectional study, 20 obese youth with T2D underwent T1-weighted brain magnetic resonance imaging (MRI). Comparisons were made to 20 age, race and sex similar controls. Differences in global and regional GMV between groups were identified using voxel-based morphometry (VBM). Results: Youth with T2D had a significantly lower global GMV-to-intracranial volume ratio (0.51±0.02 in T2D vs. 0.53±0.02 in controls, p=0.02, Cohen’s d =0.85). There were 14 regions where GMV was significantly lower in the T2D group, and nine of these were found in either the temporal or occipital lobes. There were six regions with increased GMV in T2D. All regional differences were significant at p<0.05 after adjusting for multiple comparisons. Conclusions: Results from this pilot study show obese youth with T2D have significantly lower global GMV and regional GMV differences, when compared to their age, race and sex similar peers. Future work is needed to determine whether these brain findings are a direct result of adolescent-onset T2D.

Background: The objectives were to describe the frequency of clinical presentation at the onset of type 1 diabetes mellitus (T1DM) and to estimate the prevalence of T1DM among children and adolescents in the AL-Baha region, Saudi Arabia, aiming for early diagnosis of T1DM. Methods: The clinical and laboratory data of 471 children and adolescents who presented with T1DM and received medical care at an AL-Baha diabetic center during the period from 2007 to 2016 were retrospectively analyzed based on the records. Results: The prevalence of T1DM in the AL-Baha region was 355 per 100,000 population in participants aged from 0 to 19 years. T1DM was more common among girls than boys (57.5% vs. 42.5%, respectively; p=0.3), and the female/male ratio was 1.36 in favor of girls. Hyperglycemic symptoms were the most frequent symptoms at presentation [59.2% vs. 40.8% with diabetic ketoacidosis (DKA)], and 37% of them presented with loss of weight. Most of the ketoacidosis was mild to moderate (80.2%), while only 19.8% of children had the severe type and DKA was more common (55.2%) among females. The mean age at diagnosis of T1DM was 8.2±3.5 years for all patients, and 8.3±3.9 and 8.9±3.6 years for boys and girls, respectively (p=0.06). Hyperglycemic symptoms were more common in spring (15.9%). Conclusions: The prevalence of type 1 diabetes in the AL-Baha region was 355 per 100,000 population, which is one of the highest reported prevalences in this age group. Hyperglycemic symptoms were the most encountered symptoms at the onset of the presentation of T1DM and this may help in early detection of diabetic symptoms by patients and physicians to avoid the more severe types of presentation.

Background: Obesity affects all major organ systems and leads to increased morbidity and mortality. Whole blood viscosity is an important independent regulator of cerebral blood flow. The aim of the present study was to evaluate the effect of whole blood viscosity on cerebral artery blood flow velocities using transcranial Doppler ultrasound in pediatric patients with obesity compared to healthy controls and analyze the effect of whole blood viscosity and blood pressure status to the cerebral artery blood flow velocities. Methods: Sixty patients with obesity diagnosed according to their body mass index (BMI) percentiles aged 13–18 years old were prospectively enrolled. They were grouped as hypertensive or normotensive according to their ambulatory blood pressure monitoring. Whole blood viscosity and middle cerebral artery velocities by transcranial Doppler ultrasound were studied and compared to 20 healthy same aged controls. Results: Whole blood viscosity values in hypertensive (0.0619±0.0077 poise) and normotensive (0.0607±0.0071 poise) groups were higher than controls (0.0616±0.0064 poise), with no significance. Middle cerebral artery blood flow velocities were higher in the obese hypertensive (73.9±15.0 cm/s) and obese normotensive groups (75.2±13.5 cm/s) than controls (66.4±11.5 cm/s), but with no statistical significance. Conclusions: Physiological changes in blood viscosity and changes in blood pressure did not seem to have any direct effect on cerebral blood flow velocities, the reason might be that the cerebral circulation is capable of adaptively modulating itself to changes to maintain a uniform cerebral blood flow.

Background: Many studies have reported the association between body mass index (BMI) and fasting lipid profiles in children. However, little information exists about the screening of dyslipidemia in the non-fasted state. This study assessed whether BMI can predict non-fasting lipid abnormalities in children. Methods: Using gender-separated analysis, 3895 boys and 3866 girls (aged 11–12 years) were investigated. Total cholesterol (TC), triglyceride (TG) and HDL-cholesterol (HDL-C) were measured, and non-HDL-C (=TC−[HDL-C]) was calculated. A BMI z -score was employed as the weight status. Gender-specific 95th percentiles of TC, TG and non-HDL-C were defined as “elevated”, with the 5th percentiles of HDL-C defined as “reduced”. Results: TG and non-HDL-C were positively, and HDL-C was negatively correlated with the BMI z -score in both genders. Both obese (2<BMI z -score) and overweight (1<BMI z -score≤2) were associated with the risks of elevated TG, non-HDL-C and reduced HDL-C. In both genders, a receiver operating characteristic curve demonstrated that the utility of predicting the above lipid abnormalities was moderate; the areas under the curve ranged from 0.60 to 0.70. The optimal cut-off for the BMI z -score for predicting elevated TG, non-HDL-C and reduced HDL-C were 0.52, 0.55 and 0.51 in boys and 0.34, 0.38 and 0.35 in girls, respectively. Conclusions: The BMI could be an indicator of abnormalities of non-fasting TG, non-HDL-C and HDL-C in both genders.

Background: There is a high prevalence of vitamin D deficiency (VDD) in India. Molecular mechanisms suggest a strong relationship between vitamin D and growth factors. However, there is a paucity of literature with regard to a relationship between insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein-3 (IGFBP-3) and vitamin D particularly in subjects with VDD. The objective of the study was to assess the relationship between growth factors and serum vitamin D-parathormone (PTH) status in school girls and study the impact of vitamin D supplementation on growth factors in pre-pubertal girls with VDD. Methods: Our study subjects were apparently healthy school girls aged 6–18 years. The baseline height, weight, body mass index (BMI), pubertal status, serum 25-hydroxy vitamin D (25OHD), PTH, IGF-1 and IGFBP-3 were assessed in 847 girls aged 6–18 years and in 190 pre-pubertal girls with VDD following supplementation. Results: The mean age, BMI and serum 25OHD of girls were 11.5±3.2 years, 18.7±4.8 kg/m 2 and 9.9±5.6 ng/mL, respectively. VDD was observed in 94.6% of girls. Unadjusted serum IGF-1 levels and IGF-1/IGFBP-3 molar ratio were significantly higher in girls with severe VDD as compared to girls with mild-to-moderate VDD. However, these differences disappeared when adjusted for age, height or sexual maturation. The serum IGF-1 and IGFBP-3 levels increased significantly post supplementation with vitamin D. Conclusions: There were no differences in serum IGF-1 levels and the IGF-1/IGFBP-3 molar ratio among VDD categories when adjusted for age, height and sexual maturation in girls. Vitamin D supplementation resulted in a significant increase in serum IGF-1 levels in VDD pre-pubertal girls.

Background: Children with long-chain fatty acid β-oxidation disorders (LCFAOD) presenting with clinical symptoms are treated with a specialist infant formula, with medium chain triglyceride (MCT) mainly replacing long chain triglyceride (LCT). It is essential that the safety and efficacy of any new specialist formula designed for LCFAOD be tested in infants and children. Methods: In an open-label, 21-day, phase I trial, we studied the safety of a new MCT-based formula (feed 1) in six well-controlled children (three male), aged 7–13 years (median 9 years) with LCFAOD (very long chain acyl CoA dehydrogenase deficiency [VLCADD], n=2; long chain 3-hydroxyacyl CoA dehydrogenase deficiency [LCHADD], n=2; carnitine acyl carnitine translocase deficiency [CACTD], n=2). Feed 1 (Lipistart; Vitaflo) contained 30% energy from MCT, 7.5% LCT and 3% linoleic acid and it was compared with a conventional MCT feed (Monogen; Nutricia) (feed 2) containing 17% energy from MCT, 3% LCT and 1.1% linoleic acid. Subjects consumed feed 2 for 7 days then feed 1 for 7 days and finally resumed feed 2 for 7 days. Vital signs, blood biochemistry, ECG, weight, height, food/feed intake and symptoms were monitored. Results: Five subjects completed the study. Their median daily volume of both feeds was 720 mL (range 500–1900 mL/day). Feed 1 was associated with minimal changes in tolerance, free fatty acids (FFA), acylcarnitines, 3-hydroxybutyrate (3-HB), creatine kinase (CK), blood glucose, liver enzymes and no change in an electrocardiogram (ECG). No child complained of muscle pain or symptoms associated with LCFAOD on either feed. Conclusions: This is the first safety trial reported of an MCT formula specifically designed for infants and children with LCFAOD. In this short-term study, it appeared safe and well tolerated in this challenging group.

Background: We aimed to evaluate the clinical follow-up data of patients with premature thelarche and determine the rate of development of precocious and early puberty in these patients. Methods: The charts of 158 girls with premature thelarche who were followed-up in our pediatric endocrinology polyclinic were reviewed. The patients were divided into three groups according to the age at onset: group 1 (0–1 month) (n=12), group 2 (1–24 months) (n=40) and group 3 (2–8 years) (n=106). Results: At admission, the mean height standard deviation score (SDS), body weight (BW)-SDS, body mass index (BMI) and BMI-SDS were significantly higher in group 3 than in group 1 and group 2. At admission, 8.8% of the patients were obese and 24% of the patients were overweight. The majority of patients who were obese and overweight were in group 3. At the end of the follow-up, thelarche regressed in 24.7%, persisted in 32.9%, progressed in 25.9% and had a cyclic pattern in 16.5% of the patients. Precocious or rapidly progressive puberty developed in 47 of the 158 patients (29.7%). The mean age at progression to early or rapidly progressive puberty was 98.1±17.6 months. A total of 89.3% of the patients who progressed to early or rapidly progressive puberty were in group 3. Conclusions: Precocious or rapidly progressive puberty developed in 29.7% of subjects with premature thelarche. As patients who developed rapidly progressive puberty had a higher BW-SDS and BMI-SDS than those who did not, it is suggested that the increase in weight could stimulate rapidly progressive puberty in cases with premature thelarche.

Background: Globally, there is a secular trend towards the reduced age for sexual maturity and menarche. This study aimed to determine the current age and factors associated with attainment of various stages of puberty in Nigerian girls. Methods: This study was a cross-sectional study involving 800 girls aged 6–15 years. The subjects were selected by stratified random sampling method from schools in Oshodi Local Government Area, Lagos State. They were interviewed and a physical examination was carried out to classify them into the various Tanner stages of breast and pubic hair maturational stages. Results: The median age of girls at first stage of breast maturation (B2), first stage of pubic hair development (PH2) and at menarche were 9.0, 9.0 and 12.0 years, respectively. Breast development was significantly related to normal nutritional status (adjusted odds ratio [AOR] 4.5, p<0.001), overweight (AOR 40.2, p<0.001), obesity (AOR 154.2, p<0.001) and upper social class (AOR 15.7, p<0.031). Pubic hair development was significantly related only to overweight (AOR 4.7, p<0.007) and obesity (AOR 15.7, p<0.001) while achievement of menarche was significantly related to overweight (AOR 0.1, p=0.005), obesity (AOR 0.1, p=0.0009), high social class (AOR 4.7, p<0.001) and being a member of the Hausa tribe (AOR 35.8, p<0.029). Conclusions: There is decline in age of pubertal maturation of girls in Nigeria and the major contributory factors appear to be overweight and obesity. These findings are consistent with the pattern in developed countries.

Background: This study aimed to identify the predictive value of basal sex hormone levels for activation of the hypothalamic–pituitary–gonadal (HPG) axis in girls. Methods: Gonadotropin-releasing hormone (GnRH) stimulation tests were performed and evaluated in a total of 1750 girls with development of secondary sex characteristics. Correlation analyses were conducted between basal sex hormones and peak luteinizing hormone (LH) levels ≥5 IU/L during the GnRH stimulation test. Receiver operating characteristic (ROC) curves for basal levels of LH, follicle-stimulating hormone (FSH), LH/FSH, and estradiol (E2) before the GnRH stimulation test were plotted. The area under the curve (AUC) and 95% confidence intervals (CIs) were measured for each curve. Results: The maximum AUC value was observed for basal LH levels (0.77, 95% CI: 0.74–0.79), followed by basal FSH levels (0.73, 95% CI: 0.70–0.75), the basal LH/FSH ratio (0.68, 95% CI: 0.65–0.71), and basal E2 levels (0.61, 95% CI: 0.59–0.64). The appropriate cutoff value of basal LH levels associated with a positive response of the GnRH stimulation test was 0.35 IU/L, with a sensitivity of 63.96% and specificity of 76.3% from the ROC curves when Youden’s index showed the maximum value. When 100% of patients had peak LH levels ≥5 IU/L, basal LH values were >2.72 IU/L, but the specificity was only 5.45%. Conclusions: Increased basal LH levels are a significant predictor of a positive response during the GnRH stimulation test for assessing activation of the HPG axis in most girls with early pubertal signs.

Background: PHKG2 gene mutation can lead to liver phosphorylase kinase (PhK) deficiency, which is related to glycogen storage disease type IX (GSD IX). GSD IXc due to PHKG2 mutation is the second most common GSD IX. Methods: We identified a novel mutation (c.553C>T, p.Arg185X) in PHKG2 in a Chinese family and verified it by next-generation and Sanger sequencing. The mutation spectrum of the PHKG2 gene was summarized based on 25 GSD IXc patients with PHKG2 mutations. Results: We found that missense mutation (39%) was the most common type of mutation, followed by nonsense mutation (23%). Mutations were more prevalent in Asian (12/25) and European (9/25) populations than in populations from elsewhere. The exons had more sites of mutation than the introns, and exons 3 and 6 were the most frequent sites of mutations. Conclusions: This study expands our knowledge of the PHKG2 gene mutation spectrum, providing a molecular basis for GSD IXc.

Background: Biotinidase deficiency (BD) is an autosomal recessive inborn error of metabolism characterized by neurologic and cutaneous symptoms and can be detected by newborn screening. Newborn screening for BD was implemented in Turkey at the end of 2008. Methods: In total, 203 patients who were identified among the infants detected by the newborn screening were later confirmed to have BD through measurement of serum biotinidase activity. We also performed BTD mutation analysis to characterize the genetic profile. Results: Twenty-seven mutations were identified. The most commonly found variants were c.1330G>C (p.D444H), c.1595C>T (p.T532M), c.470G>A (p.R157H), and c.198_104delGCGGCTGinsTCC (p.C33Ffs ) with allele frequencies of 0.387, 0.175, 0.165 and 0.049, respectively. Three novel pathogenic and likely pathogenic variants were identified: p.W140* (c.419G>A), p.S319F (c.956C>T) and p.L69Hfs*24 (c.192_193insCATC). We also identified three mutations reported in just one patient in the past (p.V442Sfs*59 [c.1324delG], p.H447R [c.1340A>G] and p.198delV [c.592_594delGTC]). Although all of the patients were asymptomatic under the treatment of biotin, only one patient, who had the novel c.419G>A homozygous mutation became symptomatic during an episode of acute gastroenteritis with a presentation of ketosis and metabolic acidosis. Among the screened patients, 156 had partial and 47 had profound BD. Conclusions: We determined the mutation spectra of BD from the southeastern part of Turkey. The results of this study add three more mutations to the total number of mutations described as causing BD.

Background: As K ATP channel mutations are the most common cause of neonatal diabetes mellitus (NDM) and patients with these mutations can be treated with oral sulfonylureas, empiric therapy is a common practice for NDM patients. Case presentation: A non-syndromic, small for gestational age baby born to first-degree consanguineous parents was diagnosed with NDM. Because of hypo- and hyperglycemic episodes and variability in insulin requirement, we initiated a trial of glibenclamide, with a presumptive diagnosis of NDM caused by a K ATP channel mutation. However, this empiric sulfonylurea trial did not improve the patient’s glycemic control and resulted in resistance to exogenous insulin. Genetic testing identified a previously reported homozygous INS promoter mutation (c.-331C>G), which was not responsive to sulfonylurea therapy. Conclusions: In light of our results, we recommend to confirm the genetic diagnosis as soon as possible and decide on sulfonylurea treatment after a genetic diagnosis is confirmed.

Background: Y:autosome translocations are reported to be associated with male infertility and azoospermia. Female cases with Y:autosome translocation are extremely rare. Case presentation: We report a unique case of a rare unbalanced translocation t(Y;13) in a 12-year-old girl with Turner syndrome. Combined cytogenetic testing helped to demonstrate the detail of rare chromosomal structural rearrangement in this patient. Conclusions: The presented case showed femaleness phenotype and failure of masculinization with presence of Y chromosome and the SRY gene. She was treated with growth hormone (GH) therapy after confirming the presence of only female internal gonad with laparoscopy.

Background: IGSF1 abnormality causes diverse symptoms, including congenital central hypothyroidism (CCH), prolactin hyposecretion, testicular enlargement and delayed puberty. Case presentation: Here, we report a case of a male patient who visited our hospital with a chief complaint of abdominal pain and short stature, in whom we identified a novel IGSF1 mutation. He was closely examined because of chronic constipation since infancy, persistent abdominal pain at 14 years of age and marked short stature (−4.7 standard deviation [SD] for normal Japanese boys). He was diagnosed with CCH. Decreased prolactin (PRL) secretion was also observed. IGSF1 analysis revealed a novel mutation at the splicing donor site (c.2065+1G>A) in intron 11. In silico analysis predicted this mutation to be a non-functional splice donor site. After thyroid hormone replacement, his thyroid function, constipation and growth rate improved. Conclusions: This is the first report of a patient in whom constipation and short stature led to a diagnosis of CCH with a novel IGSF1 mutation.

Background: Sex steroids are essential for sexual maturation, linear growth and bone development. However, there is no consensus on the optimal timing, dosage and dosage interval of testosterone therapy to induce pubertal development and achieve a normal adult height and bone mass in children with hypogonadism. Case presentation: A monozygotic monochorial male twin pair, of which one boy was diagnosed with anorchia at birth due to testicular regression syndrome was followed from the age of 3 until the age of 18 years. Low dose testosterone substitution (testosterone esters 25 mg/2 weeks) was initiated in the affected twin based on the start of pubertal development in the healthy twin and then gradually increased accordingly. Both boys were followed until age 18 and were compared as regards to linear growth, sexual maturation, bone maturation and bone development. Before puberty induction both boys had a similar weight and height. During puberty, a slightly faster weight and height gain was observed in the affected twin. Both boys ended up however, with a similar and normal (near) adult height and weight and experienced a normal development of secondary sex characteristics. At the age of 17 and 18 years, bone mineral density, body composition and volumetric bone parameters at the forearm and calf were evaluated in both boys. The affected boy had a higher lean mass and muscle cross-sectional area. The bone mineral density at the lumbar spine and whole body was similar. Trabecular and cortical volumetric bone parameters were comparable. At one cortical site (proximal radius), however, the affected twin had a smaller periosteal and endosteal circumference with a thicker cortex. Conclusions: In conclusion, a low dose testosterone substitution in bilateral anorchia led to a normal onset of pubertal development and (near) adult height. Furthermore, there was no difference in bone mineral density at the age of 17 and 18 years.