Copy Number Variation in GCK in Patients With Maturity-Onset Diabetes of the Young

PURPOSE

Next generation sequencing (NGS) methods to diagnose maturity-onset diabetes of the young (MODY), a monogenic autosomal dominant cause of diabetes, do not typically detect large-scale copy number variations (CNVs). New techniques may allow assessment for CNVs using output data from targeted NGS, without requiring additional sequencing. Using this technique, two kindreds of patients presenting with features of MODY were found to bear the same heterozygous large-scale deletion in GCK.

METHODS

Patients suspected of having MODY but with negative targeted NGS pathogenic variant calling were reanalyzed using the CNV caller tool (VarSeq v1.4.3). Two patients were identified as having a possible heterozygous whole exon deletion affecting exon 1 of GCK. For confirmation and determination of the exact breakpoints, whole exome sequencing followed by Sanger sequencing were used. Familial samples from both affected and nonaffected first-degree relatives were then analyzed for each proband.

RESULTS

A heterozygous whole-exon deletion spanning 4763 bp affecting the entire exon 1 of GCK was detected in two apparently unrelated patients with clinical features of MODY. This deletion showed segregation concordance across generations in affected and nonaffected family members.

CONCLUSIONS

Our findings confirm the utility of applying the CNV caller tool to screen for CNVs in GCK from NGS data. In so doing, we identified a deletion of exon 1 of GCK as likely causal for MODY. Our data indicate that incorporating CNV analysis routinely when assessing for MODY via targeted NGS may increase diagnostic yield and reduce false negative genetic testing rates.

A public health enhanced surveillance system for a mass gathering event

BACKGROUND

From June 7 to June 9, 2018, a G7 Summit was held in the Canadian province of Quebec. This international political mass gathering event posed a number of potential risks to public health.

OBJECTIVE

To assess three additional monitoring strategies to detect public health threats during a mass gathering event.

INTERVENTION

In addition to routine public health monitoring, a partnership was created and three monitoring strategies were put in place three days before, during and six days after the G7 event: the analysis of data on the presenting complaint and discharge diagnosis from 11 emergency departments in the area using the logical Early Aberration Reporting System; the daily polling of key health partners with an online questionnaire; and the analysis of calls to Info-Santé, a government-run telephone consultation service for the public regarding health and social issues.

RESULTS

Emergency room data produced 78 alerts from the presenting complaints and 39 alerts from the discharge diagnoses. Of these 117 alerts, two were investigated (one in the respiratory and one in the neurological-muscular categories) and no other interventions were required. With a few exceptions, all of the health partners completed the online survey each day and no signal of concern was generated. Compared with historical data, no increase or differences in calls to Info-Santé were detected during the monitoring period.

CONCLUSION

The three additional monitoring strategies developed to detect events of public health importance during the 2018 G7 Summit in Quebec were successful in gathering timely data for analysis. Close collaboration and good participation from the different partners were essential to this project. However, because no public health event occurred, it was not possible to determine whether the enhanced surveillance system had sufficient speed and sensitivity for timely detection and response.

Sleep and quality of life of patients with glycogen storage disease on standard and modified uncooked cornstarch

BACKGROUND

Glycemic control in hepatic glycogen storage diseases (GSDs) relies on specific nutritional recommendations, including strict avoidance of a fasting period. Uncooked cornstarch (UCCS) is an important therapeutic component. A new modified UCCS, Glycosade™, was created with the objective of prolonging euglycemia. We aimed to determine the length of euglycemia on Glycosade™ using a continuous glucose monitor (CGM) and to evaluate whether longer euglycemia and thus less nighttime interruptions would improve sleep and quality of life (QoL) after the introduction of the modified cornstarch.

METHODS

We conducted a prospective cohort study to assess quality and quantity of sleep and quality of life (QoL) in patients with GSDs on standard UCCS and after the introduction of Glycosade™. Sleep and QoL evaluation was done for patients using validated questionnaires, a standardized sleep diary and actigraphy. Length of fast and glucose variability were determined with CGM.

RESULTS

Nine adults with GSD Ia took part in the study. Glycosade™ introduction was done under close supervision during a hospital admission. Comparison of sleep in 9 patients showed sleep disturbances on standard UCCS that were improved with Glycosade™. QoL was normal both pre and post Glycosade™. The CGM confirmed maintenance of a longer fasting period with Glycosade™ at home.

CONCLUSION

Glycosade™ represents an alternative option for GSD patients. We showed possible benefits in terms of sleep quality. We also confirmed the longer length of fast on Glycosade™.

SYNOPSIS

A new modified form of uncooked starch for patients with glycogen storage disease represents an alternative option as it showed a longer length of fast and improvements in sleep quality.

Premature Ovarian Failure in French Canadian Leigh Syndrome

In all surviving girls with Leigh syndrome, French Canadian variety, a mitochondrial disease, we detected premature ovarian failure, manifested as absent or arrested breast development, lack of menarche, high follicle-stimulating hormone, a prepubertal uterus, and small ovaries. Pubertal onset and progression should be evaluated in girls with mitochondrial diseases.

Quality of referral of short children to the paediatric endocrinologist and impact of a fax communication system

BACKGROUND/OBJECTIVES

In 2001, a chart review of children referred to the authors' endocrine clinic because of short stature revealed that many were referred with insufficient baseline data, had normal height velocity and were within genetic target height. Therefore, a two-way fax communication system was implemented between referring physicians and the authors' service before the first visit. Aspects that were assessed included whether this system increased the information accompanying the patient at referral, resulted in children with nonpathological shortness not being seen in the clinic, and was used differently by paediatricians and general practitioners.

STUDY DESIGN

Between January and December 2006, 138 referrals for short stature, diagnosed with familial short stature, constitutional delay or idiopathic short stature, were audited (69 with and 69 without previous fax communication). Data collected included source of referral, clinical information provided, available growth measurements, and results from laboratory and imaging studies.

RESULTS

Fax communication resulted in growth curves being provided more often (95.6% of cases versus 40.5% of cases without fax communication [P<0.001]) and more investigations being performed by the referring physician (median [range]: six [zero to 13] investigations versus one [zero to 11]; P<0.001), as well as a diagnosis of nonpathological short stature being given to 31 children based on the growth curve, laboratory and imaging results, without the children being seen in the endocrine clinic. Fax communication was also used more frequently by paediatricians (84%) than by general practitioners (15%).

CONCLUSION

The fax communication system resulted in a more complete evaluation of referred patients by their physicians and reduced the number of unnecessary visits to the authors' specialty clinic while promoting medical education.

A search for variables predicting cortisol response to low-dose corticotropin stimulation following supraphysiological doses of glucocorticoids

OBJECTIVES

To determine which biological or clinical variables may predict cortisol response to low-dose adrenocorticotropic hormone (ACTH) stimulation following supraphysiological doses of glucocorticoids in children.

STUDY DESIGN

This retrospective study included all patients who underwent ACTH testing (1 μg) between October 2008 and June 2010 at the Sainte-Justine University Hospital Center, Montreal, after supraphysiological doses of glucocorticoids.

RESULTS

Data from 103 patients (median age, 8.0 years; range, 0.6-18.5 years; 57 girls) were analyzed, revealing growth deceleration in 37% and excessive weight gain in 33%. Reasons for glucocorticoid treatment included asthma (n = 30) and hematologic (n = 22), dermatologic (n = 19), rheumatologic (n = 16), and miscellaneous (n = 16) disorders. The following information was recorded: duration of glucocorticoid treatment (median, 374 days; range, 5-4226 days); duration of physiological hydrocortisone replacement (median, 118 days; range, 0-1089 days); maximum daily (median, 200 mg/m(2)/day; range, 12-3750 mg/m(2)/day) and cumulative (median, 16 728 mg/m(2); range, 82-178 209 mg/m(2)) doses, in hydrocortisone equivalents; and interval since the last dose (median, 43 days; range, 1-1584 days). Sixty-two patients (58%) exhibited a normal response (ie, peak cortisol >500 nmol/L) to ACTH stimulation. Peak cortisol level was not related to sex, prior morning cortisol level, duration of treatment, or cumulative glucocorticoid dose; 28% of the patients with normal baseline cortisol levels nevertheless demonstrated a subnormal response to ACTH.

CONCLUSION

Given the absence of clinical or biological predictors of the cortisol response to ACTH after suppressive doses of glucocorticoids, physicians have only 2 options: (1) empirically advocate glucocorticoid stress coverage during 18 months after cessation of high-dose glucocorticoid treatment; or (2) perform serial ACTH testing in all such patients until a normal peak cortisol level is attained.

Bioinactive ACTH causing glucocorticoid deficiency

CONTEXT

A 4-year-old girl and a 4-month-old boy presented with hypoglycemia, normal electrolytes, low cortisol, and high ACTH. A diagnosis of primary adrenal insufficiency was made and initial treatment was with glucocorticoids and mineralocorticoids. The genes known to cause ACTH resistance were normal. Whole exome sequencing revealed that the girl was compound heterozygous for POMC mutations: one previously described null allele and one novel p.R8C mutation in the sequence encoding ACTH and α-MSH. The boy was homozygous for the p.R8C mutation.

HYPOTHESIS

The p.R8C ACTH mutant is immunoreactive, but the mutant peptides, ACTH-R8C and α-MSH-R8C, are bioinactive.

METHODS

Methods included whole exome sequencing, Sanger sequencing, peptide synthesis, ACTH immunoradiometric assay, hormone binding, and activation assays in cells expressing melanocortin receptors.

RESULTS

ACTH-R8C was immunoreactive but failed to bind and activate cAMP production in melanocortin-2 receptor (MC2R)-expressing cells, and α-MSH-R8C failed to bind and stimulate cAMP production in MC1R- and MC4R-expressing cells.

CONCLUSION

These are the first documented cases of glucocorticoid deficiency due to the secretion of an ACTH molecule that lacks biological bioactivity but conserves immunoreactivity. POMC mutations should thus be considered in patients presenting with apparent ACTH resistance. Our findings also highlight a limitation to immunoassay-based diagnostics and demonstrate the value of genetic analysis. Establishing the molecular etiology of the disorder in our patients allowed cessation of the unnecessary mineralocorticoids. Finally, discovery of this mutation indicates that in humans, the amino acid sequence His(6)Phe(7)Arg(8)Trp(9) is important not only for cAMP activation but also for ACTH binding to MC2R.

Why are children living in poverty getting fatter?

In recent decades, there has been a dramatic increase in unhealthy weight for both children and adults. The Canadian standard of living has changed in favour of more easily prepared, calorie-dense foods and sedentary practices. Many family characteristics have also changed over the past 50 years. More Canadian families are living in disadvantaged situations, forecasting a host of unhealthy behaviours and attitudes in adults. The poor are not only getting poorer, they are also becoming heavier. Children from disadvantaged families seem to be leading the trend in increasing prevalence of unhealthy weight. Because they live in neighbourhoods that are perceived as unsafe, these children are likely spending more time indoors. This is associated with watching more television, which not only displaces other forms of educational and active entertainment but also places them at risk of learning inaccurate information about proper eating. Social science research helps identify factors contributing most to the rise in excess weight within this population, thus providing essential clues for effective approaches to its eradication.

Severe cortisol deficiency associated with reversible growth hormone deficiency in two infants: what is the link?

CONTEXT

Hypoglycemia is potentially life-threatening, especially in infants, and can be due to congenital cortisol and/or GH deficiency (GHD).

CASE ILLUSTRATION

Two full-term infants had undetectable cortisol levels, but also low GH levels, at the time of severe hypoglycemia. GHD persisted for several months, even after cortisol replacement.

METHODS

Targeted molecular investigations were performed and revealed homozygous inactivating mutations in MRAP (MIM ID 609196) in patient 1 and in TPIT (MIM ID 604614) in patient 2. Because GHD is not part of the MRAP or TPIT phenotypes, we performed GH stimulation tests. These revealed that GHD had resolved by 8 months (patient 1) and 3 yr (patient 2) of glucocorticoid replacement. GH replacement was therefore stopped, hypoglycemia did not recur, and over the subsequent 10 yr, growth and puberty have proceeded normally.

CONCLUSIONS

1) Physiological glucocorticoid levels appear to be required for the development and function of the somatotrophs during infancy. 2) Eucortisolism, like euthyroidism, is required for the proper evaluation of GH secretory capacity. 3) The metabolic effect of GH replacement is essential for the maintenance of normoglycemia, especially in infants. And 4) targeted molecular investigations are a powerful tool to clarify the diagnosis in severely ill infants and to reevaluate the specific treatment they need.

Is ultrasonography useful in predicting thyroid cancer in children with thyroid nodules and apparently benign cytopathologic features?

BACKGROUND/AIMS

To assess whether the presence of certain findings on thyroid ultrasonography (US) correctly diagnoses malignancy even when a fine-needle aspiration biopsy (FNAB) suggests a benign lesion.

METHODS

We reviewed the charts of 35 children and adolescents with a thyroid nodule who had had an US and a FNAB, and for whom final pathology was available.

RESULTS

The global accuracy of FNAB was 83%, with a sensitivity of 75% and a specificity of 94%. 14 FNABs suggested malignancy (40%), only 1 of which was a false positive (7%). By contrast, 5 of the 21 FNABs suggesting benign lesions were false negatives (24%). These 5 cases had US findings suggestive of malignancy. When FNAB suggested a benign lesion, US had a good sensitivity (80%) but a poor specificity and accuracy (50 and 57%, respectively); its negative predictive value was 90% and its positive predictive value 36%.

CONCLUSIONS

US complements FNAB in the evaluation of thyroid nodules in children. A more aggressive approach is warranted in children with a thyroid nodule and a benign FNAB if US findings suggest malignancy.

Elevated serum 25(OH)D concentrations, vitamin D, and calcium intakes are associated with reduced adipocyte size in women

Recent studies have suggested a beneficial effect of vitamin D and calcium on adipocyte metabolism and the metabolic profile. Our objective was to examine associations of vitamin D intake, calcium and dairy products as well as serum 25(OH)D concentration with adiposity measures and adipocyte size in women. Omental and subcutaneous adipose tissue samples were obtained from 43 women undergoing gynecological surgeries. Adipocyte size was measured using adipocyte suspensions from collagenase-digested fat tissues. Total and visceral adiposity were assessed by dual-energy X-ray absorptiometry and computed tomography, respectively. Serum 25(OH)D was measured by radioimmmunoassay. Dietary intakes were assessed using a food frequency questionnaire. Women consuming two or more dairy product portions daily had smaller adipocytes in the omental depot compared to women consuming less than two portions daily (79 ± 12 vs. 94 ± 16 µm, P ≤ 0.01). Dietary intakes of calcium (r = -0.55) and vitamin D (r = -0.43) as well as serum 25(OH)D (r = -0.35) were also inversely and significantly associated with omental adipocyte size (P ≤ 0.05 for all). Dietary vitamin D intake was inversely associated with visceral adipose tissue area (r = -0.34, P ≤ 0.05). Serum 25(OH)D was also inversely associated with visceral adipose tissue area (r = -0.32) as well as with total adipose tissue area (r = -0.44), subcutaneous adipose tissue area (r = -0.36), BMI (r =-0.43) and total body fat mass (r = -0.41, P ≤ 0.05 for all). In conclusion, elevated dietary vitamin D intake and serum 25(OH)D values are related to lower visceral adiposity and omental adipocyte size in women.

The impact of exercise consultation on activity levels and metabolic markers in obese adolescents: a pilot study

Objective. To assess the impact of exercise consultation on physical activity (PA) levels, anthropometric measures, and metabolic markers in obese adolescents. Methods. Obese adolescents (14-18 years) were randomized to either an exercise consultation (intervention group) or to review "Canada's Physical Activity Guide for Youth" (control group). Outcomes, including accelerometry, anthropometrics, blood pressure, stage of exercise behavior change, fasting glucose, insulin, and lipids, were measured at baseline and 3 months later. Results. Thirty adolescents (mean BMI = 36.1 kg/m(2); SD = 6.9) completed the study. At follow-up, the intervention group had significantly greater PA compared with controls (P < .05). Similarly, the intervention group weighed an average 2.6 kg less than the control group (P < .05), with a mean BMI z-score of 2.15 compared to 2.21 for controls (P = .054). No other differences were noted. Conclusion. Exercise consultation may be a simple approach to increase PA levels, reduce weight, and lower BMI in obese adolescents.

Outcome after bariatric surgery in two adolescents with hypothalamic obesity following treatment of craniopharyngioma

Treatment of craniopharyngioma (CP) in childhood can lead to severe, debilitating obesity with devastating medical and psychological outcomes. Despite sustained nutritional and exercise-oriented interventions, no efficacious medical option is available for hypothalamic obesity. We describe two adolescents who developed morbid obesity and significant comorbidities following diagnosis and treatment of CP, in whom bariatric surgery was achieved, illustrating a novel approach for symptomatic hypothalamic obesity, as well as positive and negative outcomes.

Fat depot-specific impact of visceral obesity on adipocyte adiponectin release in women

Our objective was to examine omental and subcutaneous adipocyte adiponectin release in women. We tested the hypothesis that adiponectin release would be reduced to a greater extent in omental than in subcutaneous adipocytes of women with visceral obesity. Omental and subcutaneous adipose tissue samples were obtained from 52 women undergoing abdominal hysterectomies (age: 47.1 +/- 4.8 years; BMI: 26.7 +/- 4.7 kg/m(2)). Adipocytes were isolated and their adiponectin release in the medium was measured over 2 h. Measures of body fat accumulation and distribution were obtained using dual-energy X-ray absorptiometry and computed tomography, respectively. Adiponectin release by omental and subcutaneous adipocytes was similar in lean individuals; however, in subsamples of obese or visceral obese women, adiponectin release by omental adipocytes was significantly reduced while that of subcutaneous adipocytes was not affected. Omental adipocyte adiponectin release was significantly and negatively correlated with total body fat mass (r = -0.47, P < 0.01), visceral adipose tissue area (r = -0.50, P < 0.01), omental adipocyte diameter (r = -0.43, P < 0.01), triglyceride levels (r = -0.32, P < or = 0.05), cholesterol/high-density lipoprotein (HDL)-cholesterol (r = -0.31, P < or = 0.05), fasting glucose (r = -0.39, P < or = 0.01), fasting insulin (r = -0.36, P < or = 0.05), homeostasis model assessment index (r = -0.39, P < or = 0.01), and positively associated with HDL-cholesterol concentrations (r = 0.33, P < or = 0.05). Adiponectin release from subcutaneous cells was not associated with any measure of adiposity, lipid profile, or glucose homeostasis. In conclusion, compared to subcutaneous adipocyte adiponectin release, omental adipocyte adiponectin release is reduced to a greater extent in visceral obese women and better predicts obesity-associated metabolic abnormalities.

Continuous glucose monitoring: a review of biochemical perspectives and clinical use in type 1 diabetes

Self-monitoring of blood glucose is a fundamental part of diabetes management. It is mandatory for tight glucose control. For the past 30 years, intermittent measurement of capillary blood glucose has been the method of choice for self-monitoring. The main disadvantage of such measurements is that they provide isolated glucose values which do not reflect variations occurring throughout the day and night. Hence systems monitoring blood glucose concentrations on a "continuous basis" have been developed. In clinical studies, different devices were shown to provide useful information on glycemic excursions in people with diabetes with sufficient accuracy. Thus, in clinical practice, this approach has also been shown to help in the medical management leading to a reduction in glycated hemoglobin and glycemic variability. However, because of lack of experience, this technology has yet to replace standard capillary blood glucose monitoring. In this paper, we review the biochemical perspectives of continuous glucose monitoring and its clinical use in type 1 diabetes.

Circulating IL-6 concentrations and abdominal adipocyte isoproterenol-stimulated lipolysis in women

OBJECTIVE

To examine the association of plasma interleukin-6 (IL-6) concentrations with adiposity and fat cell metabolism in women.

METHODS AND PROCEDURES

Omental (OM) and subcutaneous (SC) adipose tissue samples were obtained from 48 healthy women (age: 47+/-5 years, BMI: 26.9+/-5.3 kg/m(2)) undergoing gynecological surgeries. Total and visceral adiposity were assessed by dual-energy X-ray absorptiometry and computed tomography, respectively. Measures of adipocyte lipolysis (basal, isoproterenol-, forskolin-, and cyclic dibutyryl-adenosine monophosphate (AMP)-stimulated) and adipose tissue lipoprotein lipase (LPL) activity were obtained. Plasma IL-6 was measured by radioimmunoassay.

RESULTS

Plasma IL-6 was positively correlated with total body fat mass (r=0.32, P<0.05), SC adipose tissue area (r=0.35, P<0.05), SC adipocyte diameter (r=0.30, P<0.05), and a trend was observed with visceral adipose tissue area (r=0.20, P<0.07). Plasma IL-6 was positively correlated with glycerol released in response to isoproterenol (10(-5) to 10(-8) mol/l) by isolated SC (0.31 <or= r <or= 0.65, P<0.05) and OM (0.36 <or= r <or= 0.40, P<0.02) adipocytes, independent of menopausal status. No correlation was found with LPL activity. A subsample of women with high plasma IL-6 (n=10) was matched with women with low plasma IL-6 (n=10) for total body fat mass. OM adipocyte glycerol release in response to isoproterenol (10(-5) to 10(-8) mol/l) was higher in the subsample of women with elevated plasma IL-6 (P <or= 0.07).

DISCUSSION

We observed that OM lipolysis was significantly higher in women with elevated plasma IL-6 for a similar body fat mass and menopausal status. These results suggest that higher circulating IL-6 concentrations are associated with increased isoproterenol-stimulated lipolysis especially in OM abdominal adipocytes in women.

Hypertrophy and hyperplasia of abdominal adipose tissues in women

OBJECTIVE

To examine the expression of selected transcription factors involved in adipogenesis and genes related to lipid metabolism in abdominal subcutaneous and omental fat tissue.

RESEARCH DESIGN AND METHODS

We obtained subcutaneous and omental adipose tissue samples from 40 women undergoing abdominal hysterectomies (age: 47+/-5 years; BMI 27.9+/-5.3 kg/m(2)). We measured isolated adipocyte size and metabolism, and detailed measures of body fat accumulation and body fat distribution were obtained (dual-energy X-ray absorptiometry and computed tomography, respectively).

RESULTS

Adipocyte size of both subcutaneous and omental fat were increased with higher body fat mass values, with similar regression slopes in each compartment. In contrast, with higher body fat mass values, fat accumulation was progressively higher in the subcutaneous than in the visceral fat compartment, suggesting hyperplasia in the subcutaneous fat compartment. Messenger RNA levels of CEBPalpha, PPARgamma2, SREBP1c and genes related to lipid metabolism (LPL, FABP4, DGAT1, DGAT2, PLIN and HSL) were significantly higher in subcutaneous than in omental fat tissue (P< or =0.001 for all). Only subcutaneous expression of these genes tracked with obesity levels as reflected by significant positive associations between subcutaneous fat CEBPalpha, SREBP1c and DGAT2 expression and total body fat mass (r=0.37, r=0.41, r=0.57, respectively, P< or =0,05), fat percentage (r=0.40, r=0.39, r=058, respectively, P< or =0,05) and subcutaneous adipose tissue area (r=0.36, r=0.38, r=0.58, respectively, P< or =0,05). Omental adipose tissue expression levels of these genes were not significantly related to adiposity measures.

CONCLUSIONS

These results show that in obese women, hyperplasia is predominant in the subcutaneous fat depot, whereas fat cell hypertrophy is observed both in the omental and subcutaneous compartments.

Cumulative doses of adjunct 131I treatment depend on location of residual thyroid tissue after total thyroidectomy in differentiated thyroid cancer

PURPOSE

The aim of this study was to review the outcome after adjunct postoperative 131I therapy in patients with differentiated thyroid carcinoma (DTC) treated with total thyroidectomy (excluding medullary thyroid carcinoma).

METHODS

Retrospective chart review: Management protocol is total thyroidectomy with cervical node sampling, 131I whole-body scan 3 weeks postoperatively to document residual thyroid tissue or metastatic lesions. Adjunct treatment consists of one or more 131I (100-200 mci/1.73 m2). Patients are considered disease free if 2 consecutive 131I whole-body scan are negative with undetectable thyroglobulin level.

RESULTS

Twenty-one patients, 14 females and 7 males, with a mean age of 13.6 years were treated. Whole-body scan postoperatively revealed uptake in the thyroid bed (TB) in 10 patients, in cervical lymph nodes (CLN) in 9 patients, and in CLN and lungs in 2 patients. Patients with residual uptake in TB received a significantly lesser dose of 131I (mean, 122 +/- 53 mci) than those with metastatic CLN (357 +/- 182 mci) (P < .004) (t test) or lung mets (523.5 mci). With a mean follow-up of 7.8 years (range, 1-16 years), overall survival is 100% but disease-free survival is 100%, 66%, and 0% respectively for patients with residual disease in TB, CLN, and lungs.

CONCLUSION

Patient with residual thyroid tissue in the TB required a significantly lesser number of treatments and doses of 131I compared to patients with cervical node metastases with a 100% disease-free survival. The best management of immediate postoperative residual cervical nodes (surgical excision vs 131I) remains to be defined. The efficacy of 131I therapy in patients with lung metastases remains controversial with complete remission unlikely.

Cognition and behavior at school entry in children with congenital hypothyroidism treated early with high-dose levothyroxine

OBJECTIVE

To document cognition and behavior at school entry in these patients. Study design Eighteen children with congenital hypothyroidism (CH; 9 severe and 9 moderate, based on a surface of the knee epiphyses at diagnosis<or >or=0.05 cm(2)) treated from a median of 14 days with a median of 12.0 microg/kg per day of levothyroxine were evaluated at 5 years, 9 months, with the McCarthy Scale and the Questionnaire for Evaluation of Social Behavior, as were 40 control children.

RESULTS

The global IQs at 5 years, 9 months, were similar: medians (range) were 102 (87 to 133), 102 (84 to 135), and 115 (88 to 136) (not significant) for severe CH, moderate CH, and control children, respectively. The behavioral scores of CH children were within the normal range. However, the number of times when plasma TSH was >6.0 mIU/L during treatment was correlated positively with anxiety (P=.02) and inattention (P=.05), whereas the number of times TSH was <0.8 mIU/L was correlated with lower verbal scores (P=.05).

CONCLUSIONS

Children with severe CH treated early with a high dose of levothyroxine have normal global development and behavior at school entry.

Hyperfunctioning malignant thyroid nodule in an 11-year-old girl: pathologic and molecular studies

We identified a papillary carcinoma in an 11-year-old girl with a hyperfunctioning thyroid nodule. A met453thr mutation in TSHR was found in the nodule but not in normal thyroid tissue or in leukocytes. This case documents that this activating mutation is associated with neoplasia.

Outcome of pediatric Graves' disease after treatment with antithyroid medication and radioiodine

OBJECTIVE

To evaluate the efficacy of antithyroid medication in the initial treatment of pediatric Graves' disease and the frequency of use and outcome of radioiodine as second-line therapy.

DESIGN

Retrospective review.

SETTING

Tertiary care children's hospital.

PATIENTS

Thirty-three patients (29 female, 4 male; mean age 12.7 years) who started treatment for hyperthyroidism between Jan. 1, 1990, and Dec. 31, 1994.

INTERVENTIONS

Initial treatment with propylthiouracil or methimazole (with addition of levothyroxine if needed to maintain euthyroidism); subsequent treatment with radioiodine.

OUTCOME MEASURES

1) Clinical and laboratory features at the time of diagnosis; 2) doses and duration of antithyroid drug treatment and response to treatment; 3) need for treatment with levothyroxine to maintain euthyroidism during the trial of antithyroid medication; 4) indications for radioiodine therapy, and the dose and number of treatments with 131iodine (131I); 5) thyroid status at last follow-up visit (at least 2 years after diagnosis).

RESULTS

All patients were initially treated with antithyroid drugs, and levothyroxine was added in 16 subjects to maintain euthyroidism. The median duration of drug treatment was 21 months. Ultimately, 24/33 patients (73%) received radioiodine following a trial of antithyroid drugs because of a) side effects of antithyroid medication (in 3 patients); b) inadequate response to medication (in 8 patients); and c) relapse (in 13 patients), which occurred at a median of 6 (range 1 to 16) months following cessation of drug therapy. Five patients required a second dose of radioiodine and 2 patients required 3 doses. Of the 24 patients treated with radioiodine, at last follow-up after the most recent treatment (median 18.5, range 3 to 55 months), 6 patients were euthyroid, 16 required thyroxine replacement, and 2 were-still, or again, hyperthyroid.

CONCLUSION

In our population of children and adolescents, treatment of hyperthyroidism with antithyroid drugs frequently resulted in either side effects, inadequate response to medication or subsequent relapse, all of which led to radioiodine therapy. We conclude, therefore, that radioiodine could be considered as one of the first-line options in older children and adolescents with hyperthyroidism.

Severe autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy in an adolescent girl with a novel AIRE mutation: response to immunosuppressive therapy

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare autosomal recessive disorder for which the gene (AIRE) has recently been identified on chromosome 21q22.3. We present the mutational analyses of a French-Canadian family with APECED, in which there are two affected siblings, as well as the response to cyclosporine A(CyA) therapy in the index patient, the eldest sibling. Haplotype analysis suggested compound heterozygozity at the AIRE locus. Direct sequencing of exon 8 revealed a previously described mutation, a 13-bp deletion (1085-1097) of maternal origin, found in the index patient, her affected sister, and her unaffected sister. A novel missense mutation characterized by a T-->G transversion at nucleotide position 398, resulting in a leu-->arg amino acid substitution (L93R), was found in exon 2. The mutation was present in the father, the brother, the index patient, and the affected sister. The presence of the mutation in the propositus was verified by cloning of PCR products from genomic DNA. The mutation destroys a PstI restriction enzyme site, as confirmed in the aforementioned patients. Screening of 50 French-Canadian controls with PstI digestion did not show destruction of the restriction-enzyme site. The index patient's phenotype was severe, manifested by classic features of the illness (adrenal insufficiency, hypoparathyroidism, candidiasis, and keratoconjunctivitis with alopecia universalis), as well as by severe exocrine pancreatic insufficiency, diabetes mellitus, hepatic inflammation, growth hormone (GH) deficiency due to lymphocytic hypophysitis, and primary ovarian failure. Oral CyA (5 mg/kg/day) was initiated at 13 yr of age. After 8 months of therapy, stimulated pancreatic lipase increased 24-fold with normalization of stool fat (from 31.5 g/day to 2.5 g/day, normal(N) < 5). There was complete resolution of her photophobia, and considerable hair regrowth was diffusely apparent. Minimal side effects were noted. Our experience supports the use of oral CyA for the treatment of severe APECED-associated exocrine pancreatic failure and keratoconjunctivitis.

Prophylactic thyroidectomy for medullary thyroid carcinoma in gene carriers of MEN2 syndrome

BACKGROUND/PURPOSE

Although medullary thyroid carcinoma (MTC) can occur sporadically, in the pediatric population it is most often associated with the multiple endocrine neoplasia syndrome (MEN type 2). Traditional screening was based on evaluation of basal and stimulated serum calcitonin levels. The recent cloning of the MEN2 gene on the RET proto-oncogene of chromosome 10 now allows for testing of gene carrier status in individuals at risk who could benefit from prophylactic treatment. The current study was undertaken to determine the appropriate age for safe total prophylactic thyroidectomy.

METHODS

Over a 16-year period, 12 patients with a family history of MEN2A and one with a MEN2B underwent total thyroidectomy and central neck dissection without parathyroid autotransplantation. Four patients (31%) were treated previously for Hirschsprung's disease.

RESULTS

In seven patients (mean age, 11.8 years) undergoing biochemical screening for diagnosis, multifocal MTC and C cell hyperplasia (CCH) were found in all the resected specimens. Of six patients identified with genetic screening (mean age, 9.1 years), two had elevated stimulated calcitonin levels, one (age 14) had evidence of MTC, and one (age 6) had CCH. Four patients with normal calcitonin levels had no evidence of MTC (ages 6, 8, 10) but there was one occurrence of CCH (age 11). No permanent postoperative hypoparathyroidism or recurrent laryngeal nerve damage occurred in this series. With a mean follow-up of 4 years (range, 1 to 14 years), the overall disease-free survival is 100%.

CONCLUSIONS

From this study the authors conclude that total thyroidectomy can be performed safely in children and should be the treatment of choice in patients with a family history of MEN2A carrying a germinal RET mutation even if the serum basal or stimulated serum calcitonin level is normal. Total thyroidectomy should be performed as early as 5 years of age before the occurrence of CCH or MTC.

Severe congenital hypopituitarism with low prolactin levels and age-dependent anterior pituitary hypoplasia: a clue to a PIT-1 mutation

A 20-month-old boy presented with severe congenital growth hormone, thyrotropin, and prolactin deficiencies resulting from a de novo mutation of the PIT-1 gene. This form of congenital hypopituitarism should be suspected if pituitary anatomy is normal, especially if prolactin levels are low and, in boys, if the external genitalia are normal. Pituitary atrophy appears to be an age-dependent phenomenon in this condition.

A novel mechanism for isolated central hypothyroidism: inactivating mutations in the thyrotropin-releasing hormone receptor gene

Isolated central hypothyroidism, characterized by insufficient TSH secretion resulting in low levels of thyroid hormones, is a rare disorder. We report a boy in whom isolated central hypothyroidism was diagnosed at 9 yr of age. Complete absence of TSH and PRL responses to TRH led us to speculate that he had an inactivating mutation of the TRH receptor gene. The patients' genomic DNA was isolated, and the entire coding region of the TRH receptor was amplified by the PCR and sequenced directly. Confirmation of the mutations and haplotyping of the family was performed using restriction enzymes. The biological activity of the wild-type and mutated TRH receptors was verified by evaluating the binding of labeled TRH and stimulation by TRH of total inositol phosphate accumulation in transfected HEK-293 and COS-1 cells. The patient was found to be a compound heterozygote, having inherited a different mutated allele from each of the parents; both mutations were in the 5'-part of the gene. Mutated receptors were unable to bind TRH and to activate total inositol phosphate accumulation. Our report is the first description of naturally occurring inactivating mutations of a G protein-coupled receptor linked to the phospholipase C second messenger pathway. The prevalence and phenotypic spectrum of TRH receptor mutations in isolated central hypothyroidism remain to be established.

[Pubertal development after pediatric heart transplantation]

Twenty-one children and adolescents underwent orthotopic cardiac transplantation at the Hôpital Sainte-Justine between July 1984 and June 1993. Of those patients, 16 (4 girls and 12 boys) who survived more than one year after the procedure were followed prospectively for documentation of onset and progression of puberty. The immunosuppressive therapy included cyclosporine, azathioprine and prednisone. Subjects were evaluated at 6 month intervals for the study of: pubertal development according to staging by the method of Marshall and Tanner and hormonal profile (FSH, LH, testosterone, DHEAS). Despite a stagnation of pubertal signs before surgery, puberty carried on and progressed normally postoperatively. The urinary levels of gonadotropins rose to adequate levels for age. Testosterone levels in boys were related to the progression of secondary sexual characteristics. Levels of DHEAS were drastically reduced, most likely because of the supraphysiological doses of oral glucocorticoids. Our results indicate that after pediatric heart transplantation, puberty progresses normally at adolescence.

Thyroid scintigraphy in children and adolescents with Hashimoto disease

Between 1989 and 1994, 58 children and adolescents with Hashimoto thyroiditis seen at the Sainte-Justine Hospital had thyroid scintigraphy. Their medical records and films were reviewed retrospectively. Eighty-nine percent of the patients had a homogeneous distribution of tracer on thyroid scintigraphy, unlike the heterogeneous distribution classically reported in adults. In children and adolescents, thyroid scintigraphy is not helpful in the diagnosis of typical Hashimoto thyroiditis.

Outcome in three siblings with antibody-mediated transient congenital hypothyroidism

A woman receiving thyroxine substitution therapy for acquired hypothyroidism caused by autoimmune thyroiditis gave birth to three babies who had transient primary hypothyroidism. All three babies had elevated thyrotropin levels on neonatal screening, but one had normal thyroxine values. Thyrotropin receptor-blocking antibodies were present in maternal serum and in the three neonates. Each baby also had a different congenital malformation. The neurodevelopmental outcome of the children appeared related in part to maternal thyroxine levels, which suggests that transplacental transfer of thyroxine may protect the fetal brain.

Increased cyclic guanosine monophosphate production and overexpression of atrial natriuretic peptide A-receptor mRNA in spontaneously hypertensive rats

Atrial natriuretic peptide (ANP) specifically stimulates particulate guanylate cyclase, and cyclic guanosine monophosphate (cGMP) has been recognized as its second messenger. Spontaneously hypertensive rats (SHR) have elevated plasma ANP levels, but manifest an exaggerated natriuretic and diuretic response to exogenous ANP when compared to normotensive strains. In isolated glomeruli, the maximal cGMP response to ANP corresponds to a 12- to 14-fold increase over basal levels in normotensive strains (Wistar 13 +/- 2; Wistar-Kyoto 12 +/- 2; Sprague-Dawley 14 +/- 2) while a maximal 33 +/- 3-fold elevation occurs in SHR (P < 0.001). This hyperresponsiveness of cGMP is reproducible in intact glomeruli from SHR from various commercial sources. Furthermore, this abnormality develops early in life, even before hypertension is clearly established, and persists despite pharmacological modulation of blood pressure, indicating that it is a primary event in hypertension. In vitro studies have revealed a higher particulate guanylate cyclase activity in membranes from glomeruli and other tissues from SHR. This increase is not accounted for by different patterns of ANP binding to its receptor subtypes between normotensive and hypertensive strains, as assessed by competitive displacement with C-ANP102-121, an analog which selectively binds to one ANP receptor subtype. The hyperactivity of particulate guanylate cyclase in SHR and its behavior under basal, ligand (ANP), and detergent-enhanced conditions could be attributed either to increased expression or augmented sensitivity of the enzyme. Radiation-inactivation analysis does not evoke a disturbance in the size of regulatory elements normally repressing enzymatic activity, while the expression of particulate guanylate cyclase gene using mutated standard of A- and B-receptors partial cDNAs, quantified by polymerase chain reaction (PCR) transcript titration assay, manifests a selective increase of one guanylate cyclase subtype. Our data suggest that in hypertension, genetic overexpression of the ANP A-receptor subtype is related to the exaggerated biological response to ANP in this disease.

Nature and frequency of chromosomal abnormalities in pregnancies with abnormal ultrasound findings: an analysis of 117 cases with review of the literature

During a 7-year period, 117 fetal karyotypes were available from 131 genetic amniocenteses. These procedures were performed between 14 and 37 weeks' gestation for the following abnormal ultrasound findings: (1) intrauterine growth retardation (IUGR)--61 cases; (2) fetal malformation--71 cases; and (3) amniotic fluid volume (AFV) abnormality--60 cases. Chromosomal abnormalities were identified in 19 cases (16.2 per cent). Aneuploidy was 2.5 times as frequent in the presence of malformations than in their absence. No correlation was demonstrated between specific fetal malformations and specific chromosomal abnormalities. Aneuploidy was also twice as frequent in the presence of symmetrical IUGR than in its absence. No chromosomal abnormalities were found among eight cases of asymmetrical IUGR. Four cases of aneuploidy presented with isolated IUGR, three of these involving the X chromosome. The frequency of aneuploidy was the same with or without abnormalities of AFV (14.3 versus 16.4 per cent). No chromosomal abnormality was found associated with isolated AFV abnormalities.

Characterization of the functional domains of the natriuretic peptide receptor/guanylate cyclase by radiation inactivation

Radiation inactivation has been used to evaluate the molecular size of domains responsible for atrial natriuretic peptide (ANP)-binding and cyclase functions of the ANP receptor/guanylate cyclase. Two types of inactivation curves were observed for cyclase function in both adrenal cortex and aortic smooth muscle cells: 1) biphasic with enhanced guanylate cyclase activity after exposure to low radiation doses and 2) linear after preincubation of membrane proteins with 0.5 microM ANP or solubilization with Triton X-100. The existence of an inhibitory component was the simplest model that best explained the types of radiation curves obtained. Activation of guanylate cyclase by ANP or Triton X-100 could occur via the dissociation of this inhibitory component from the catalytic domain. On the other hand, the loss of ANP-binding activity was linear with increasing radiation exposures under basal, ANP treatment, and Triton X-100 solubilization conditions. Radiation inactivation sizes of about 30 kDa for cyclase function, 20 kDa for ANP-binding function, and 90 kDa for inhibitory function were calculated. These studies suggest that the ANP receptor/guanylate cyclase behaves as a multidomain protein. The results obtained by radiation inactivation of the various biological functions of this receptor are compatible with the hypothesis of an intramolecular inhibitory domain repressing the guanylate cyclase catalytic domain within its membrane environment.

Cell biology of atrial natriuretic peptide

Atrial natriuretic peptide (ANP) exhibits a wide spectrum of cardiovascular, endocrine, metabolic and renal actions. cGMP is the major mediator of ANP at the cellular level and only tissues possessing particulate guanylate cyclase appear to present ANP-induced actions. Three types of ANP receptors have recently been cloned. Two of them (A and B receptors) are homologous and contain guanylate cyclase catalytic domains. The C receptor could possibly regulate the metabolic fate of ANP. Data obtained by the radiation inactivation method suggest the presence of an inter- or intramolecular inhibitory component of nearly 90 kilodaltons that represses the catalytic activity of guanylate cyclase within its membrane environment. The mechanism of guanylate cyclase stimulation by ANP could involve this inhibitory component. Preliminary data suggest that the hyperresponsiveness of the particulate guanylate cyclase/cGMP system in hypertension occurs through modulation of the inhibitory component.

Control of phospholipid turnover and prolactin release in a dopamine-sensitive, prolactin-secreting rat pituitary adenoma and in two dopamine-resistant, prolactin-secreting rat pituitary tumors

Abstract The secretion of prolactin by the pituitary gland is under a tonic inhibitory control exerted by tubero-infundibular dopamine. Recently, it has been suggested that dopamine may exert its action by inhibiting production of inositol phosphates and mobilization of intracellular Ca(2+). To study the effects of dopamine on the production of inositol phosphates and prolactin release, we have utilized an estrone-induced, dopamine-sensitive rat pituitary adenoma and two transplantable and dopamine-resistant rat pituitary tumors, 7315a and MtTW15. Purified cells, obtained from the three tissues, were incubated for 30 min in media with drugs (thyrotropin-releasing hormone or angiotensin II) stimulating inositol phosphates and prolactin release, in the presence or the absence of dopamine. Basal production of inositol phosphates and prolactin release by adenomatous lactotrophs were inhibited by dopamine. Thyrotropin-releasing hormone and angiotensin II stimulated inositol phosphates by adenomatous and 7315a cells. This effect was antagonized by dopamine in adenomatous cells. Prolactin release by adenomatous cells only was stimulated by thyrotropin-releasing hormone and angiotensin II. This stimulation was inhibited by dopamine. The results show differences, in the mechanisms of regulation of prolactin release, between adenoma and transplantable pituitary tumors as well as between the two tumors themselves. These differences may be responsible, in part, for the resistance of the two transplantable pituitary tumors to the inhibitory effects of dopamine on prolactin release and tumor size. Our results obtained both with adenoma and tumoral cells also suggest that inositol phosphates probably intervene only in the late phases of dopamine inhibition of prolactin release and only in the presence of a normal Ca(2+) signaling system.

Reduced pituitary volume in children with short stature: clinical and radiological correlates

A retrospective evaluation of 80 cases of growth retardation evaluated at the Hôpital Sainte-Justine of Montreal has revealed that 20 of them (25%; 15 boys and 5 girls) had a reduction of pituitary volume as revealed by high-resolution CT scanning of the pituitary gland. Of these patients, 8 had complete growth hormone (GH) deficiency, as evaluated by arginine infusion and L-Dopa-propranolol testing and nocturnal blood sampling, and 3 had GH neurosecretory dysfunction. Five patients had combined or multiple hormonal deficiencies. A statistically significant correlation was found between nocturnal plasma GH values and pituitary volumes. From this study it can be concluded that reduced pituitary volume is a frequent finding in growth-retarded children with hypopituitarism.

Efficacy of intranasal or subcutaneous luteinizing hormone-releasing hormone agonist inhibition of ovarian function in the treatment of endometriosis

We have previously reported reversible hypogonadism induced by the intranasal administration of the luteinizing hormone-releasing hormone agonist buserelin as a new therapeutic approach for endometriosis. Thirteen patients were randomized to receive intranasal buserelin (400 micrograms 3 times a day) or subcutaneous buserelin injection (200 micrograms once daily) for a 6- to 9-month period. Both routes of administration were effective in inhibiting serum estradiol levels to near the menopausal range after 1 month of treatment. The two dosage regimens had also a comparable efficacy in alleviating endometriosis symptoms and in reducing the revised American Fertility Society scoring at laparoscopic examination. The implant score mainly decreased by more than 70%. The occurrence of side effects was similar in both groups, and side effects were mainly hot flushes, dyspareunia secondary to decreased vaginal secretion, and decreased libido. Results of hemogram, urinalysis, and serum biochemical and hormonal tests remained in the normal range. The ovulatory cycle rapidly returned after the cessation of treatment, and three pregnancies occurred in six previously infertile patients. Intranasal and subcutaneous buserelin were well accepted and equally effective in inhibiting the pituitary-ovarian function, which caused mild menopausal symptoms but an important regression of endometriosis.

Congenital malformations associated with maternal use of valproic acid

Two children born with birth defects after intrauterine exposure to valproic acid are reported. The mothers took the drug throughout pregnancy as sole treatment for primary generalized epilepsy. The first baby showed facial dysmorphism, arachnodactyly and triphalangeal thumbs. The second had facial dysmorphism, severe laryngeal hypoplasia, tracheomalacia and an aberrant innominate artery that caused tracheal compression. A left superior vena cava, abnormal pulmonary lobulation, and unilateral hydronephrosis were also found at autopsy. Valproic acid has probable teratogenic potential in humans but the number of reported cases is few and the spectrum of anomalies is broad so it is not possible to delineate a definite fetal valproate syndrome.