International Journal of Pediatric Endocrinology最新文献

Glucose homeostasis requires appropriate and synchronous coordination of metabolic events and hormonal activities to keep plasma glucose concentrations in a narrow range of 3.5-5.5 mmol/L. Insulin, the only glucose lowering hormone secreted from pancreatic β-cells, plays the key role in glucose homeostasis. Insulin release from pancreatic β-cells is mainly regulated by intracellular ATP-generating metabolic pathways. Hyperinsulinaemic hypoglycaemia (HH), the most common cause of severe and persistent hypoglycaemia in neonates and children, is the inappropriate secretion of insulin which occurs despite low plasma glucose levels leading to severe and persistent hypoketotic hypoglycaemia. Mutations in 12 different key genes (ABCC8, KCNJ11, GLUD1, GCK, HADH, SLC16A1, UCP2, HNF4A, HNF1A, HK1, PGM1 and PMM2) constitute the underlying molecular mechanisms of congenital HH. Since insulin supressess ketogenesis, the alternative energy source to the brain, a prompt diagnosis and immediate management of HH is essential to avoid irreversible hypoglycaemic brain damage in children. Advances in molecular genetics, imaging methods (¹⁸F-DOPA PET-CT), medical therapy and surgical approach (laparoscopic and open pancreatectomy) have changed the management and improved the outcome of patients with HH. This up to date review article provides a background to the diagnosis, molecular genetics, recent advances and therapeutic options in the field of HH in children.

Background: Testicular volumes obtained with orchidometers or external linear measurements in the scrotum (centimeter ruler or calipers) grossly over-estimate ultrasound volumes, have much variability and may not be accurate or reproducible. The reference of the values obtained by orchidometers or US, to age or Tanner stages is not useful to determine the normal values for stages of puberty, because overlapping of ages and values. Pubertal development is determined by two events, genital and pubic hair development, that should be analyzed independently because one could be out of step with the other. The ultrasound (US) measurement of testicular volumes is the gold standard but is somewhat inconvenient, because it requires another procedure and, mainly, is costly. The solution of the problems would be to determine testicular volumes matching US values, from the width of the testis obtained in the scrotum with a centimeter ruler, by formulas recently described, and to reference them to the stages of genital development.

Methods: The width and length of the testes in the scrotum with a centimeter ruler were obtained in 159 study subjects, in different stages of genital development and adults, for a total of 318 testicular determinations, from the age of 3 to 34 years. The width obtained in the scrotum was corrected by subtracting the values of the double scrotal skin (ss). The formulas were then applied and the testicular volumes matching US values were calculated. The volumes and the range of ages for different stages of genital development were determined. Penile measurements were obtained in 145 subjects and pubic and other hair recorded. Paired and unpaired 2 tail student t-test was used to compare the means of the different groups expressed as means and SD and, in addition the Wilcoxon rank sum test and Bootstrap methods for the testicular volume groups. A p value of 0.05 or less was considered significant. The Institutional Review Board (IRB) of Nationwide Children's Hospital determined that this study did not require IRB approval.

Results: With a simple measurement of the width of the testis in the scrotum, with a centimeter ruler, testicular volumes matching US values were calculated and normative values for each stage of genital development were determined.

Conclusion: This information should solve present problems.

Background: De novo truncating and splicing mutations in the additional sex combs-like 3 (ASXL3) gene have been implicated in the development of Bainbridge-Ropers syndrome (BRPS) characterised by severe developmental delay, feeding problems, short stature and characteristic facial features.

Case presentation: We describe, for the first time, a patient with severe short stature, learning difficulties, feeding difficulties and dysmorphic features with a novel compound heterozygous mutation in ASXL3.Additionally the patient also has primary insulin like growth factor-1 (IGF1) deficiency. The mutations occur in exon 11 and proximal part of exon 12 and are strongly conserved at the protein level across various species. In-silico analyses using PolyPhen-2 and SIFT predict the amino acid substitutions to be potentially deleterious to the protein function. Detailed bioinformatics analysis show that the molecular defects caused by the two compound heterozygous mutations synergistically impact on two points of the molecular interaction network of ASXL3.

Conclusion: We hypothesise that ASXL3 potentially has a role in transcriptional activation of IGF1 involved in signalling pathways that regulate cell proliferation and growth, which could be contributing to short stature encountered in these patients.

Background: We aimed to determine the extent of post-treatment weight gain that occurs in pediatric patients in the first year following radioactive iodine (RAI) therapy for Graves disease (GD) and its relationship to clinical characteristics.

Methods: A retrospective chart review of patients receiving RAI therapy for GD between 1998-2015 was performed. Change in BMI SDS (∆BMI SDS) from baseline to one year after treatment was determined. We also investigated whether individual clinical and/or biochemical factors were associated with the weight trajectory in these patients.

Results: One hundred fifty seven patients aged 12.7 ± 3 years (80% girls) were included in the analysis. Average ∆BMI SDS was 0.70 ± 0.71 (p < 0.001) at 1 year. Patients with weight loss at presentation had a greater ∆BMI SDS than those without (0.92 vs 0.56, p = 0.005), whereas no association was seen with gender, pubertal status, use of antithyroid drugs, history of ADHD, or Down syndrome. Baseline BMI SDS was negatively correlated with ∆BMI SDS, with a stronger correlation in males. From baseline to 1 year, the proportion of overweight and obese patients increased from 9.6% to 18.5% and from 6.4% to 21%, respectively. In a subset of 81 patients, a positive correlation was noted between time to euthyroidism and ∆BMI SDS, particularly in boys.

Conclusions: The number of our patients in the overweight category doubled and the number in the obese category more than tripled in the first year following RAI treatment for GD. Anticipatory guidance regarding this important issue is badly needed.

[This corrects the article DOI: 10.1186/s13633-017-0046-x.].

Background: We report a female patient with endocrine abnormalities, hypogonadotropic hypogonadism and amazia (breasts aplasia/hypoplasia but normal nipples and areolas) in a rare syndrome: Van Maldergem syndrome (VMS).

Case presentation: Our patient was first evaluated at age 4 for intellectual disability, craniofacial features, and auditory malformations. At age 15, she presented with no breast development and other findings consistent with hypogonadotropic hypogonadism. At age 37, she underwent whole exome sequencing (WES) to identify pathogenic variants. WES revealed compound heterozygous variants in DCHS1 (rs145099391:G > A, p.P197L & rs753548138:G > A, p.T2334 M) [RefSeq NM_003737.3], diagnostic of Van Maldergem syndrome (VMS-1). VMS is a rare autosomal disorder reported in only 13 patients, characterized by intellectual disability, typical craniofacial features, auditory malformations, hearing loss, skeletal and limb malformations, brain abnormalities with periventricular neuronal heterotopia and other variable anomalies. Our patient had similar phenotypic abnormalities. She also had hypogonadotropic hypogonadism and amazia. Based on the clinical findings reported, two previously published patients with VMS may also have been affected by hypogonadotropic hypogonadism, but endocrine abnormalities were not evaluated or mentioned.

Conclusion: This case highlights an individual with VMS, characterized by compound heterozygous variants in DCHS1. Our observations may provide additional information on the phenotypic spectrum of VMS, including hypogonadotropic hypogonadism and amazia. However, the molecular genetic basis for endocrine anomalies observed in some VMS patients, including ours, remains unexplained.

Background: Hypoglycemia due to a pancreatic beta cell neoplasm - insulinoma, is uncommon with only a few cases described. We report on a previously healthy 15-year-old Hispanic female with insulinoma who presented with a loss of consciousness due to hypoglycemia unawareness.

Case presentation: EM was first brought to the emergency department (ED) after she was found unresponsive at home with point of care (POC) glucose of 29 mg/dL(1.6 mmol/L) documented by emergency medical services (EMS) upon arrival. After treatment with dextrose and normal laboratory evaluation, including complete blood count, basal metabolic profile and urine drug screen, she was sent home with recommendations to follow-up the next day with an endocrinologist. Due to insurance issues, the family did not keep the appointment. Two days later, she returned to the ED with POC of 19 mg/dL (1.05 mmol/L). Detailed history review identified vague fatigue, excessive sleepiness, poor oral intake and weight gain for a 2-3 month period and no suspicion for drug, alcohol or prescription medication abuse. Family history of multiple endocrine neoplasia was negative. Physical examination revealed mild acanthosis nigricans and a body mass index of 32.8 kg/m² (98th percentile). Laboratory evaluation showed elevated insulin with low cortisol and growth hormone levels at the time of hypoglycemia. Abdominal magnetic resonance imaging revealed a pancreatic mass, also supported by ultrasound, computed tomography and positron emission tomography scans. The patient underwent a partial pancreatectomy with removal of a well-circumscribed insulinoma from the anterior-superior aspect of the pancreatic neck confirmed by histology. Hypoglycemia resolved post-operatively and she remained euglycemic during a 48-h cure fast. At her 3-month follow-up visit, she had no symptoms of hypoglycemia.

Conclusion: Documented hypoglycemia in an otherwise healthy adolescent should be fully investigated before discharging a patient. Even a short duration of symptoms should prompt, in-depth diagnostic evaluations to rule out a potentially life threatening diagnosis of insulinoma.

The determination of the testicular volume is of considerable importance to assess the onset, progression and disorders of puberty, abnormal testicular development, and a number of other conditions; and in adults, assessment of fertility. A number of clinical methods have been used for the measurement of testicular volumes in the scrotum: a centimeter ruler, sliding calipers, and orchidometers. All the clinical methods calculate the volumes by the ellipsoid equation, grossly overestimate ultrasound (US) volumes by 70 to 80% for adults, to 150 to 250% for prepubertal subjects, mainly because the inclusion of the scrotal skin and epididymis and may not be accurate of reproducible. Ultrasound measurements have a high degree of accuracy and reproducibility and are the standard for quantitation of testicular volume. Formulas, equivalent to the ellipsoid equations used, were developed to match ultrasound volumes, with corrections of the width and length of the testis obtained in the scrotum, to avoid the inclusion of the scrotal skin (ss) and epididymis. A calculator was developed, requiring only the identification of ① the width of the testis in cm obtained in the scrotum with a ruler (without corrections) (i.e. 0.9, 1.5, 2.0, 2.4 cm etc.) and ② the stage of genital development. The calculator will subtract the scrotal skin for the stage of genital development, from the measurement of the width provided, apply the formula and identify the testicular volume of the subject that matches the US volume. The calculator will also provide, in a Table form, the values for the different stages of genital development. Benefit: The information provided by the calculator will solve the problem of overestimation by the orchidometers and the external measurements, problems with the reference of values to age, and Tanner stages, would permit assessment of the beginning and progression of puberty, of micro and macroorchidism, and other conditions mentioned.

Background: Data on normative clitoral sizes in newborns is relatively sparse and racial/ethnic differences have also been reported. This study was performed to establish norms for clitoral size in term Ghanaian female newborns.

Methods: This was a cross-sectional study of all apparently well full-term newborns of postnatal age < 48 h and birth weight between 2.5 and 4.0 kg delivered at Komfo Anokye Teaching Hospital between May and September, 2014. Anthropometric and genital parameters were documented for study subjects as well as parental socio-demographic indices.

Results: In 612 newborn females studied, the mean (±SD) clitoral length (MCL) and the mean (±SD) clitoral width (MCW) were 4.13 ± 1.6 mm and 4.21 ± 1.1 mm, respectively. MCL was inversely related to birth weight (r = -0.62; p < 0.001 ) while MCW was inversely related to both gestational age (r = -0.1; p = 0.02 ) and birth weight (r = -0.54; p < 0.001 ). Babies with a clitoris that was completely covered by the labia majora had relatively lower clitoral sizes (p < 0.001) than those who had a partially covered or prominent clitoris. Neither MCL nor MCW differed significantly by birth length or maternal tribe.

Conclusions: Clitoral size varies with birth weight and gestational age. Babies with a completely covered clitoris are unlikely to warrant detailed clitoral measurements for clitoromegaly.

Congenital hypothyroidism occurs in approximately 1 in 2000 newborns and can have devastating neurodevelopmental consequences if not detected and treated promptly. While newborn screening has virtually eradicated intellectual disability due to severe congenital hypothyroidism in the developed world, more stringent screening strategies have resulted in increased detection of mild congenital hypothyroidism. Recent studies provide conflicting evidence about the potential neurodevelopmental risks posed by mild congenital hypothyroidism, highlighting the need for additional research to further define what risks these patients face and whether they are likely to benefit from treatment. Moreover, while the apparent incidence of congenital hypothyroidism has increased in recent decades, the underlying cause remains obscure in most cases. However, ongoing research into genetic causes of congenital hypothyroidism continues to shed new light on the development and physiology of the hypothalamic-pituitary-thyroid axis. The identification of IGSF1 as a cause of central congenital hypothyroidism has uncovered potential new regulatory pathways in both pituitary thyrotropes and gonadotropes, while mounting evidence suggests that a significant proportion of primary congenital hypothyroidism may be caused by combinations of rare genetic variants in multiple genes involved in thyroid development and function. Much remains to be learned about the origins of this common disorder and about the optimal management of less severely-affected infants.