Screening for celiac disease among children with overweight and obesity: toward exploring celiac iceberg.

Background The coexistence of celiac disease (CD) and obesity/overweight is not unusual. Objective We investigate the prevalence and clinical presentation of CD, detected by screening, among children with excessive weight gain. Methods We enrolled 200 children referred for overweight/obesity to our outpatient clinic. Medical history during pregnancy and childhood and lifestyle variables were recorded. Patients were screened for CD with total immunoglobulin A (IgA), IgA anti-transglutaminase (tTG-IgA) and IgA anti-endomysial antibodies (EMA-IgA). In subjects with positive autoantibodies, esophagogastroduodenoscopy (EGDS) was performed and genetic testing for HLA DQ2 and/or DQ8 haplotypes was tested. Results CD positive antibodies (tTg-IgA and EMA-IgA) were detected in eight patients (4%); in all subjects CD diagnosis was confirmed by HLA-DQ2 and/or DQ8 compatibility and EGDS. No association between CD and medical history during pregnancy and childhood or lifestyle variables was noted; however, a dietary difference was identified with those testing positive for CD also reporting a lower weekly consumption of fruits and vegetables (p=0.04). Headache was reported more frequently in patients with than without CD (p=0.04). Familiar positivity for autoimmune diseases was revealed in CD patients (p=0.01). Conclusion CD should be considered in children with excessive weight gain. Familial predisposition to other autoimmune diseases may represent a risk factor for development of CD. Even though the relationship between headache and CD is not well defined, the patients with headache of unknown origin should be screened for CD.

Timing, prevalence, and dynamics of thyroid disorders in children and adolescents affected with Down syndrome.

Objectives Limited data on the evolution of thyroid disorders (TD) in Down syndrome (DS) are available. We characterized the timing, prevalence, and dynamics of TD in patients with DS during a long-term follow-up. Methods We retrospectively evaluated 91 children and adolescents with DS (12.5 ± 8.3; follow-up 7.5 ± 6.2). Children were monitored at birth, 6, and 12 months of age and twice a year thereafter. Thyroid status and autoimmunity were periodically investigated. Results TD were detected in 73.6% of patients, in particular congenital hypothyroidism (CH), autoimmune thyroid diseases (ATD) and subclinical hypothyroidism (SH) were recorded in 16.4, 31.8, and 25.3%, respectively. CH was diagnosed at newborn screening in 86.7% of cases and in the first 6 months of life in the remaining 13.3%; the condition was persistent in 61.5% of patients. In more than 30% of CH cases, glandular hypoplasia was also revealed. In the ATD group, 63.1% of patients with Hashimoto's disease (HD, 82.6%) were treated with levothyroxine and subjects with Graves' Disease (GD, 17.4%) started therapy with methimazole. DS with SH were treated in 42.1% of cases. A thyroid hypogenic echopattern, without autoantibody positivity was identified in 27.6% of SH patients. Conclusions The high prevalence and evolution of TD in SD requires frequent monitoring starting in the first months of life. CH can be misdiagnosed at screening. In DS subjects, there is a high prevalence of ATD and non-autoimmune diseases with early antibody-negative phases should not be excluded.

Gender Differences at the Onset of Autoimmune Thyroid Diseases in Children and Adolescents.

Background: The incidence of autoimmune thyroid diseases (ATD) may vary with the beginning of reproductive function, although few reports differentiate the incidence before and during the onset of puberty, examining gender bias. We analyzed onset of ATD in a pediatric population to assess gender differences in onset age, disease subtype, pubertal status, autoimmune co-morbidity, family history and treatment, focusing on the interaction between gender and pubertal stage. Patients and methods: We retrospectively recorded 382 children and adolescents with ATD. In each patient physical examination was considered. The presence of other associated autoimmune diseases (AAD) and familial predisposition was also recorded. Results: Predominant prevalence was noted in females compared to males (p < 0.001), both in Hashimoto's diseases (HD or HT) and Graves' disease (GD) (p < 0.001). Mean age at diagnosis showed no significant difference between sexes (p > 0.05). A higher prevalence in pubertal subjects was noted compared to prepubertal (p < 0.001, particularly HT in early and GD in late pubertal stage), without sexes difference intra-(prepubertal vs. pubertal) and inter-puberty groups (prepubertal vs. early pubertal vs. late pubertal). Both in HT and in GD, the prevalence of autoimmune associated diseases (AAD) was higher in males compared to females (p = 0.04), with similar distribution according to the pubertal maturation. The familial predisposition was similarly distributed in both genders (p > 0.05) and into pubertal stages (p > 0.05). Conclusions: Females are more prone to develop ATD during puberty, earlier in HT than in GD. The effect of puberty is not different between genders, suggesting the role of additional factors other than hormones. The screening for detection of ATD is recommended in all patients with positive family history and other autoimmune diseases, mostly in males. Considerations of gender in pediatrics could be important to define pathogenic mechanisms of ATD and to help in early diagnosis and clinical management.

Rapid progressive central precocious puberty: diagnostic and predictive value of basal sex hormone levels and pelvic ultrasound.

Objectives Data on the predictive values of parameters included in the diagnostic work-up for precocious puberty (PP) remain limited. We detected the diagnostic value of basal sex hormone levels, pelvic ultrasound parameters and bone age assessment for activation of the hypothalamic-pituitary-gonadal axis in girls with PP, in order to help in the decision to perform GnRH testing. Patients and methods We retrospectively considered 177 girls with PP. According to puberty evolution, the girls were divided into two groups: rapid progressive central precocious puberty (RP-CPP) and non/slowly progressive/transient forms (SP-PP). In all patients we considered Tanner stage, basal luteinizing hormone (LH) and estradiol (E2) values, bone age, and pelvis examination. We assessed the diagnostic value of each variable and identified the number of pathological parameters that best identify patients with RP-CPP. Results Basal LH ≥ 0.2IU/L, E2 level ≥ 50 pmol/L, uterine longitudinal diameter ≥ 3.5 cm, transverse uterine diameter ≥ 1.5 cm, endometrial echo and ovarian volume ≥ 2 cm3 were significantly associated with RP-CPP (p ≤ 0.01). The ability to diagnose RP-CPP was enhanced with increasing number of pathological hormonal and instrumental parameters (p < 0.001). With more than three parameters detected, sensitivity and specificity reached 58% (95%CI 48-67) and 85% (95%CI 74-92), respectively, with a PPV = 86% (95%CI 76-93) and PPN = 54% (95%CI 43-54); the area under the ROC curve was 0.71 (95%CI 0.65-0.78). Conclusion Despite the availability of different tests, diagnosing RP-CPP remains difficult. A diagnosis model including at least three hormonal and/or ultrasound parameters may serve as a useful preliminary step in selecting patients who require GnRH testing for early detection of RC-PP.

Gender-based differences in the clustering of metabolic syndrome factors in children and adolescents.

Background We depicted gender-differences in metabolic syndrome (MS) clustering before and after puberty in pediatrics, in order to develop gender specific preventive strategies for childhood obesity. Methods We considered 1079 children and adolescents (529 females and 550 males; mean age 11.5 ± 2.8 year). According to body mass index (BMI) percentiles the subjects were classified as normal weight BMI <75th, overweight BMI 75-95th and with obesity BMI >95th. MS was diagnosed when three of the following criteria for age and sex percentiles were met: BMI >95th, triglycerides (TGs) level >95th, high-density lipoprotein-cholesterol (HDL-c) level <5th, blood pressure (blood pressure) >95th percentile, fasting blood glucose (FBG) >100 mg/dL and/or homeostatic model assessment- insulin resistance (HOMA-IR) >97.5th percentile. Results The prevalence of dismetabolic factors was similar in both genders, except for pathological BP, which was higher in males (p = 0.02). MS was detected only in patients with obesity, with a higher prevalence in pubertal than late/post-pubertal subjects (p < 0.001), without any significant difference between gender. In pre-puberty, the most common MS combination was obesity (HBMI) + hypertension (HBP) + hyperglycemia/insulin resistance (HGLY/IR) followed by HBMI + low HDL-levels (LHDL) + HGLY/IR versus HBMI + HBP + HGLY/IR followed by HBMI + HBP + LHDL, respectively, in females and males. In the early and late/post-pubertal periods, the most prevalent combination remained similar to pre-puberty, additionally in both sexes other combinations, such as HBMI + HTG + HBP + HGLY/IR, HBMI + HBP + LHDL + HGLY/IR, HBMI + HTG + LHDL + HGLY/IR and HBMI + HTG + LHDL + HBP + HGLY/IR were also detected, differently distributed in males and females. Conclusions We confirm that MS is an important consequence related to obesity, particularly in the post-puberty stage. Some gender-based differences should be considered early in order to identify specific preventive and treatment strategies.

Autoimmune Thyroid Diseases in Children and Adolescents with Maturity Onset Diabetes of the Young Type 2.

BACKGROUND/AIM: The relationship between type 1 diabetes mellitus (T1DM) and autoimmune thyropathies is well known and has been described in the literature. Based on present knowledge, the relationship between thyropathies and other forms of diabetes, such as monogenic diabetes, has not been investigated. The aim of our study was to assess the prevalence of autoimmune thyroid diseases (ATD) in children and adolescents with maturity onset diabetes of the young type 2 (MODY2) in comparison with patients with T1DM and a control group. PATIENTS AND METHODS: We examined 23 children and adolescents with MODY2 (11 F/12 M; 13.5 ± 5.3 years) and 166 patients with T1DM (80 F/86 M; 14.0 ± 4.7 years). The control group consisted of 62 age-matched healthy subjects (34 F/28 M). ATD diagnosis was based on the finding of one or more positive thyroid autoantibodies and characteristic thyroid ultrasound lacking homogeneity, with a hypogenic or mixed echo pattern. RESULTS: ATD was diagnosed in 15 (10.5%; 9 F/6 M) patients with T1DM, in 4 with MODY2 (17.4%; 4 F), and in 1 (1.6%) control. A significantly higher ATD prevalence was detected in T1DM and MODY2 compared to the control subjects (p = 0.02), without differences between T1DM and MODY2 (p = 0.26). There were no gender differences noted in T1DM (p = 0.42); on the contrary, in MODY2 a higher prevalence was noted in females (p = 0.04). Celiac disease and a positive family history of ATD were not detected in subjects with MODY2. CONCLUSION: Our study showed an increased prevalence of ATD in patients with MODY2. Therefore, a careful follow-up of all children with MODY2 is recommended in order to assess the presence of thyroid disorders.

Evaluation of Allostatic Load as a Marker of Chronic Stress in Children and the Importance of Excess Weight.

Introduction: Allostatic load (AL) refers to the physiological response associated with the burden of chronic stress. Excessive weight is an important source of physiological stress that promotes a detrimental chronic low-inflammation state. In order to define a correlation between cumulative biological dysregulation and excess weight, we measured AL scores in a pediatric population. Patients and Methods: We enrolled 164 children and adolescents (11.89 ± 3.89). According to their body mass index (BMI) threshold, subjects were classified as normal in the BMI < 75th percentile, overweight in the BMI 75-95th percentile or obese in the BMI >95th percentile. Data based on 16 biomarkers were used to create the AL score. A dichotomous outcome for high AL was defined in those who had more than four dysregulated components. Results: High AL was noted in 88/164 subjects (53.65%), without significant differences between genders (p = 0.07) or pubertal status (p = 0.10). Subjects with a high AL, in addition to a higher BMI (p < 0.001), showed higher WC and WC/HtR (p < 0.001), triglycerides (p = 0.002), fasting blood glucose (p = 0.03), insulin resistance (p < 0.001), systolic (p < 0.001) and diastolic blood pressure (p = 0.001), GGT (p = 0.01), PCR (p = 0.01), and calprotectin (p < 0.01) as well as lower HDL cholesterol (p = 0.002) than subjects with a low AL. The rate of the cumulative biological dysregulation increased progressively with increases in BMI (p < 0.001). Conclusions: A high AL was associated with excess weight. AL may be considered a significant factor correlated with increased morbidity in children who are overweight/obese.

Triglyceride Glucose Index as a Surrogate Measure of Insulin Sensitivity in a Caucasian Pediatric Population

Objective: The triglyceride and glucose (TyG) index has been proposed as a simple surrogate of insulin resistance (IR) with high sensitivity as an IR index besides the well known homeostasis model assessment of IR (HOMA-IR). Limited data are reported in children. We investigated the sensitivity and specificity of TyG index in a pediatric Caucasian population, as a surrogate measure of IR and compared the results with HOMA-IR. Methods: We enrolled 541 children (11.7±2.71 yrs). According to body mass index (BMI) chart, the subjects were divided into three groups: normal weight BMI<75th percentile, overweight BMI 75th­95th percentile, and obese>95th percentile. TyG index was calculated as (ln[fasting triglycerides(mg/dl)×fasting plasma glucose(mg/dl)/2]) and considered pathological when exceeding 7.88. HOMA-IR was calculated as (insulin×glucose)/22.5 and defined pathological whenever exceeding 97.5th percentile for age and sex. Results: In children with overweight/obesity TyG index was higher compared to normal weight subjects (p<0.001). TyG index was correlated with BMI (p<0.001); WHtR (p<0.001), total and HDL cholesterol (p<0.001); ALT (p<0.001), blood pressure (p<0.001). A correlation between TyG index and HOMAIR (p<0.001) as well as high TyG index and pathological HOMA-IR (p<0.001) were noted. The optimal cut-off for IR was considered 7.98 (sensitivity 60%; specificity 78%; AUC 0.69). Conclusions: TyG index is a useful and cost-effective index of IR among children and adolescents. The cutoff 7.98 may be used for IR risk screening in childhood obesity, but we recommend caution when used in other populations.

Diet and Lifestyle Role in Homocysteine Metabolism in Turner Syndrome.

OBJECTIVE: Patients with Turner syndrome (TS) have an unfavorable cardiometabolic profile. Hyperhomocysteinemia is a potential cardiovascular risk factor influenced by genetic and environmental factors, therapies, unbalanced diets and other lifestyle factors. We retrospectively studied the relationship between total plasma homocysteine (Hcy), serum vitamin B12 (B12) and folate concentration in TS patients, taking into account the genetic profile, diet, smoking habits, hormonal therapies and dietary supplements of the subjects. PATIENTS AND METHODS: We evaluated 50 TS patients (31.5 ± 12.5 years). Medication, including vitamin supplementation, was obtained. Eating habits, cigarette smoking, alcohol and coffee consumption were investigated using phone interviews. Levels of Hcy metabolism parameters were classified by using the relevant cutoff value for an adult population and compared with a reference sample drawn from the general population. RESULTS: Inadequate Hcy and B12 levels were noted, despite vitamin supplementation. Holotranscobalamin (HoloTC) was above the relevant cutoff in the population, and supplemented subjects showed mean levels lower than nonsupplemented subjects (p = 0.005). Dietary supplementation (p = 0.038), lifestyle (coffee consumption, p = 0.01) and hormonal replacement therapy (p = 0.02) are important factors for Hcy metabolism. No genetic influence on Hcy levels was noted. Multivariable regression analysis identified vitamin supplementation (p = 0.045) as the only independent predictor of increased Hcy levels. CONCLUSION: Cardiovascular risk in TS can be reduced using educational approaches to a healthy lifestyle with dietary guidelines. Besides this, we also recommend measuring HoloTC for the prompt detection of B12 deficiency and to consider hormone replacement therapy in the biochemical assessment of homocysteine in TS.

Small supernumerary marker chromosomes: A legacy of trisomy rescue?

We studied by a whole genomic approach and trios genotyping, 12 de novo, nonrecurrent small supernumerary marker chromosomes (sSMC), detected as mosaics during pre- or postnatal diagnosis and associated with increased maternal age. Four sSMCs contained pericentromeric portions only, whereas eight had additional non-contiguous portions of the same chromosome, assembled together in a disordered fashion by repair-based mechanisms in a chromothriptic event. Maternal hetero/isodisomy was detected with a paternal origin of the sSMC in some cases, whereas in others two maternal alleles in the sSMC region and biparental haplotypes of the homologs were detected. In other cases, the homologs were biparental while the sSMC had the same haplotype of the maternally inherited chromosome. These findings strongly suggest that most sSMCs are the result of a multiple-step mechanism, initiated by maternal meiotic nondisjunction followed by postzygotic anaphase lagging of the supernumerary chromosome and its subsequent chromothripsis.

Serum Calprotectin Level in Children: Marker of Obesity and its Metabolic Complications.

AIM: Elevated calprotectin levels have been reported in obese adults but have not been evaluated in pediatric population. We investigated the characteristics of serum calprotectin in overweight and obese children and its association with metabolic comorbidities. METHODS: We enrolled 131 children (11.7 ± 4.1 years). According to body mass index (BMI), the subjects were divided into 3 groups: obese > 95th percentile; overweight BMI 75th-95th percentile, and normal weight BMI < 75th percentile. Patients were classified as having Metabolic Syndrome if they met 3 or more of the following criteria for age and sex: BMI > 97th percentile, triglycerides > 95th percentile, high-density lipoprotein cholesterol < 5th percentile, systolic and/or diastolic blood pressure > 95th percentile, and impaired glucose tolerance. In all patients, calprotectin serum levels were also detected. RESULTS: Calprotectin was higher in obese and overweight children than normal weight subjects (p < 0.001), with calprotectin in females being significantly higher than in males (p = 0.04). Increased calprotectin was related to pathological fasting blood glucose (p < 0.001) and insulin resistance (p = 0.03), while BMI (p = 0.001), and diastolic pressure (p = 0.001) are independent factors for increased calprotectin. CONCLUSIONS: Our findings confirm the association between increased calprotectin and obesity also in children and suggest the potential utility of this biomarker in the monitoring of its metabolic complications.

Gynecomastia after euthyroidism restoration in a patient with type 1 diabetes and Graves' disease.

In patients with autoimmune disease, gynecomastia should not be considered as 1 of the first signs of hyperthyroidism, rather it is a breast pathology that can be present even when euthyroidism restoration is achieved. It is unknown whether the autoimmune nature of thyroid disorders or simply the hyperthyroidism effects breast changes.

Smoke exposure and cardio-metabolic profile in youth with type 1 diabetes.

BACKGROUND: To evaluate the relationship between smoking and metabolic parameters in patients affected by type 1 diabetes (T1D). PATIENTS AND METHODS: We enrolled 104 children and young adults (50 females and 54 males) with T1D (aged 16.4 ± 8.6 years). The subjects were divided into three groups according to their smoking habits: no smoking (NS), passive smoking (PS), active smoking (AS). The physical examination of the participants included nutritional status assessment by anthropometry and pubertal stage according to Marshall and Tanner as well as blood pressure measurement. In all patients, metabolic blood assays including fasting blood glucose, insulin, total cholesterol, high-density lipoprotein cholesterol, and triglycerides were measured. Insulin resistance was determined by glucose disposal rate (eGDR). Physical activity was also recorded. RESULTS: Significant differences in biochemical and functional parameters among the three groups were demonstrated, in particular for systolic (p = 0.002) and diastolic pressure (p = 0.02) and eGDR (p = 0.039). No differences in daily insulin dose (p = 0.75) and glycated hemoglobin (p = 0.39) were observed. AS group had significantly higher blood pressure (p < 0.05) and lower eGDR (p ≤ 0.001) compared to NS and PS. Significant difference was also detected between PS and NS in systolic and diastolic (p = 0.02) pressure and eGDR (p = 0.01). In a multivariable model adjusted for age, gender, BMI and physical activity, smoking habits did not maintain any independent association with metabolic parameters. CONCLUSION: This is the first study in a Mediterranean population, looking at tobacco smoke and cardio-metabolic factors in youth with T1D. The relationship between smoking and unfavorable metabolic profile was demonstrated. On the basis of these findings, smoking tobacco should be considered an important modifiable risk factor for young patients with diabetes mellitus, highlighting the need for intensified smoking prevention and cessation programs.

Relation between circulating oxidized-LDL and metabolic syndrome in children with obesity: the role of hypertriglyceridemic waist phenotype.

BACKGROUND: The association between oxidative stress (OS) and metabolic syndrome (MetS) has been reported in adults. We analyzed the relation between circulating oxidized low-density lipoproteins (Ox-LDL) and MetS in pediatric ages in order to define whether plasma Ox-LDL levels are correlated to obesity and whether oxidative damage, using serum Ox-LDL levels as a proxy, are associated with MetS. METHODS: We enrolled 178 children (11.8±2.6 years). On the basis of a body mass index (BMI) threshold, the subjects were classified as: normal weight BMI <75th percentile; overweight BMI 75-97th percentile; obese BMI >97th percentile. Patients were classified as having MetS if they met three or more of the following criteria for age and sex: BMI >97th percentile, triglyceride levels >95th percentile, high-density lipoprotein (HDL) cholesterol level <5th percentile, systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) >95th percentile and impaired glucose tolerance. RESULTS: Obese children showed increased MetS prevalence (p=0.001) and higher Ox-LDL levels compared to normal- and overweight subjects (p<0.05), with a limited relation between Ox-LDL and MetS (p=0.06). Waist-to-height ratio (W/HtR) (p=0.02), triglycerides (TG) (p=0.001) and LDL-cholesterol (p<0.001) resulted independent predictors of increased plasma Ox-LDL levels. CONCLUSIONS: Oxidative damage was correlated with a hypertriglyceridemic waist phenotype and can be a precocious marker of MetS and cardiometabolic risk in obese children.

Omitting duodenal biopsy in children with suspected celiac disease and extra-intestinal symptoms.

BACKGROUND: The aim of our study is to evaluate if in children with highly positive serology and HLA-DQ2/DQ8 (triple test, TT) and only extra-intestinal symptoms, it is possible to omit performing an intestinal biopsy for celiac disease (CD) diagnosis, as suggested by the new European Society for Pediatric Gastroenterology, Hepatology and Nutrition ESPGHAN guidelines. METHODS: In this retrospective study a total of 105 patients, suspected of having CD because of extra-intestinal symptoms and showing serum tissue transglutaminase antibody (anti-tTG) and anti-endomysial antibody (EMA) measurements and HLA genotyping, were considered for the final analysis (33 boys and 72 girls; age range 1.5-17.6 years). RESULTS: Histological findings confirmed diagnosis of CD in 97 (92.4%) patients. Forty-one patients (39%) showed anti-tTG >10 times normal values, positive EMA and positive HLA-DQ2/DQ8 (positive TT). All of them had a diagnosis of CD, therefore there were no false positive cases. Sixty-four patients were negative for the TT. In eight cases, CD was ruled out and these were considered true negative cases. In the remaining 56 negative TT patients, intestinal biopsy confirmed CD diagnosis and they were considered false negatives. Based on these results, specificity for the TT was 100% and sensitivity was 42.3%. CONCLUSIONS: On the basis of the present study, diagnosis of CD can be reliably performed without a duodenal biopsy in children with only extra-intestinal symptoms.

Noninvasive assessment of liver steatosis in children: the clinical value of controlled attenuation parameter.

BACKGROUND: To assess the clinical validity of controlled attenuation parameter (CAP) in the diagnosis of hepatic steatosis in a series of overweight or obese children by using the imperfect gold standard methodology. METHODS: Consecutive children referred to our institution for auxological evaluation or obesity or minor elective surgery were prospectively enrolled. Anthropometric and biochemical parameters were recorded. Ultrasound (US) assessment of steatosis was carried out using ultrasound systems. CAP was obtained with the FibroScan 502 Touch device (Echosens, Paris, France). Pearson's or Spearman's rank correlation coefficient were used to test the association between two study variables. Optimal cutoff of CAP for detecting steatosis was 249 dB/m. The diagnostic performance of dichotomized CAP, US, body mass indexes (BMI), fatty liver index (FLI) and hepatic steatosis index (HSI) was analyzed using the imperfect gold standard methodology. RESULTS: Three hundred five pediatric patients were enrolled. The data of both US and CAP were available for 289 children. Steatosis was detected in 50/289 (17.3%) children by US and in 77/289 (26.6%) by CAP. A moderate to good correlation was detected between CAP and BMI (r = 0.53), FLI (r = 0.55) and HSI (r = 0.56). In obese children a moderate to good correlation between CAP and insulin levels (r = 0.54) and HOMA-IR (r = 0.54) was also found. Dichotomized CAP showed a performance of 0.70 (sensitivity, 0.72 [0.64-0.79]; specificity, 0.98 [0.97-0.98], which was better than that of US (performance, 0.37; sensitivity, 0.46 [0.42-0.50]; specificity, 0.91 [0.89-0.92]), BMI (performance, 0.22; sensitivity, 0.75 [0.73-0.77]; specificity, 0.57 [0.55-0.60]) and FLI or HSI. CONCLUSIONS: For the evaluation of liver steatosis in children CAP performs better than US, which is the most widely used imaging technique for screening patients with a suspicion of liver steatosis. A cutoff value of CAP of 249 dB/m rules in liver steatosis with a very high specificity.

A frequent oligogenic involvement in congenital hypothyroidism.

Congenital hypothyroidism (CH), the most frequent form of preventable mental retardation, is predicted to have a relevant genetic origin. However, CH is frequently reported to be sporadic and candidate gene variations were found in <10% of the investigated patients. Here, we characterize the involvement of 11 candidate genes through a systematic Next Generation Sequencing (NGS) analysis. The NGS was performed in 177 unrelated CH patients (94 gland-in-situ; 83 dysgenesis) and in 3,538 control subjects. Non-synonymous or splicing rare variants (MAF < 0.01) were accepted, and their functional impact was predicted by a comprehensive bioinformatic approach and co-segregation studies. The frequency of variations in cases and controls was extended to 18 CH-unrelated genes. At least one rare variant was accepted in 103/177 patients. Monogenic recessive forms of the disease were found in five cases, but oligogenic involvement was detected in 39 patients. The 167 variations were found to affect all genes independently of the CH phenotype. These findings were replicated in an independent cohort of additional 145 CH cases. When compared to 3,538 controls, the CH population was significantly enriched with disrupting variants in the candidate genes (P = 5.5 × 10-7), but not with rare variations in CH-unrelated genes. Co-segregation studies of the hypothyroid phenotype with multiple gene variants in several pedigrees confirmed the potential oligogenic origin of CH. The systematic NGS approach reveals the frequent combination of rare variations in morphogenetic or functional candidate genes in CH patients independently of phenotype. The oligogenic origin represents a suitable explanation for the frequent sporadic CH occurrence.

Contribution of LHX4 Mutations to Pituitary Deficits in a Cohort of 417 Unrelated Patients.

Context: LHX4 encodes a LIM-homeodomain transcription factor that is implicated in early pituitary development. In humans, only 13 heterozygous LHX4 mutations have been associated with congenital hypopituitarism. Objective: The aims of this study were to evaluate the prevalence of LHX4 mutations in patients with hypopituitarism, to define the associated phenotypes, and to characterize the functional impact of the identified variants and the respective role of the 2 LIM domains of LHX4. Design and Patients: We screened 417 unrelated patients with isolated growth hormone deficiency or combined pituitary hormone deficiency associated with ectopic posterior pituitary and/or sella turcica anomalies for LHX4 mutations (Sanger sequencing). In vitro studies were performed to assess the functional consequences of the identified variants. Results: We identified 7 heterozygous variations, including p.(Tyr131*), p.(Arg48Thrfs*104), c.606+1G>T, p.Arg65Val, p.Thr163Pro, p.Arg221Gln, and p.Arg235Gln), that were associated with variable expressivity; 5 of the 7 were also associated with incomplete penetrance. The p.(Tyr131*), p.(Arg48Thrfs*104), p.Ala65Val, p.Thr163Pro, and p.Arg221Gln LHX4 variants are unable to transactivate the POU1F1 and GH promoters. As suggested by transactivation, subcellular localization, and protein-protein interaction studies, p.Arg235Gln is probably a rare polymorphism. Coimmunoprecipitation studies identified LHX3 as a potential protein partner of LHX4. As revealed by functional studies of LIM-defective recombinant LHX4 proteins, the LIM1 and LIM2 domains are not redundant. Conclusion: This study, performed in the largest cohort of patients screened so far for LHX4 mutations, describes 6 disease-causing mutations that are responsible for congenital hypopituitarism. LHX4 mutations were found to be associated with variable expressivity, and most of them with incomplete penetrance; their contribution to pituitary deficits that are associated with an ectopic posterior pituitary and/or a sella turcica defect is ∼1.4% in the 417 probands tested.

Anti-Zinc Transporter Protein 8 Antibody Testing Is Not Informative in Routine Prediabetes Screening in Young Patients with Autoimmune Thyroiditis and Celiac Disease.

BACKGROUND/AIMS: Patients with type 1 diabetes mellitus (T1DM), autoimmune thyroiditis (ATD), and celiac disease (CD) are at increased risk for developing other autoimmune diseases. We evaluated zinc transporter 8 (ZnT8) prevalence in patients with ATD and/or CD in order to define the usefulness of ZnT8 autoantibodies for prediabetes screening. METHODS: Eighty-one young patients with ATD and/or CD were included in the study; 32 subjects with clinical onset of T1DM were enrolled as a control group. GAD65, IA-2, and ZnT8 antibodies were measured. An intravenous glucose tolerance test, C-peptide, glycosylated hemoglobin levels, and genomic analysis of HLA-DQA1* and -DQB1* were also considered in patients positive for autoantibodies. RESULTS: The ZnT8 prevalence was higher in T1DM patients than in patients with other autoimmune diseases (p < 0.001); positive ZnT8 detection was found in 2 ATD (p = 0.004) and 3 ATD + CD (p = 0.04) patients. Positive ZnT8 was associated with GAD65 (p = 0.01) but not with IA-2 positivity. No correlation between ZnT8 detection and the number of T1DM-susceptible HLA-DQ heterodimers was found. Pathological C-peptide levels and insulin response were found in subjects with islet autoimmunity and genetic susceptibility. CONCLUSION: ZnT8 autoantibodies detection in ATD and/or CD patients is low, and routine ZnT8 screening is not justified. ZnT8 evaluation may be recommended in subjects with autoimmune diseases as a marker for predicting compromised insulin secretion.