Central precocious puberty caused by mutations in the imprinted gene MKRN3.

BACKGROUND: The onset of puberty is first detected as an increase in pulsatile secretion of gonadotropin-releasing hormone (GnRH). Early activation of the hypothalamic-pituitary-gonadal axis results in central precocious puberty. The timing of pubertal development is driven in part by genetic factors, but only a few, rare molecular defects associated with central precocious puberty have been identified. METHODS: We performed whole-exome sequencing in 40 members of 15 families with central precocious puberty. Candidate variants were confirmed with Sanger sequencing. We also performed quantitative real-time polymerase-chain-reaction assays to determine levels of messenger RNA (mRNA) in the hypothalami of mice at different ages. RESULTS: We identified four novel heterozygous mutations in MKRN3, the gene encoding makorin RING-finger protein 3, in 5 of the 15 families; both sexes were affected. The mutations included three frameshift mutations, predicted to encode truncated proteins, and one missense mutation, predicted to disrupt protein function. MKRN3 is a paternally expressed, imprinted gene located in the Prader-Willi syndrome critical region (chromosome 15q11-q13). All affected persons inherited the mutations from their fathers, a finding that indicates perfect segregation with the mode of inheritance expected for an imprinted gene. Levels of Mkrn3 mRNA were high in the arcuate nucleus of prepubertal mice, decreased immediately before puberty, and remained low after puberty. CONCLUSIONS: Deficiency of MKRN3 causes central precocious puberty in humans. (Funded by the National Institutes of Health and others.).

A New Tool to Identify Pediatric Patients with Atypical Diabetes Associated with Gene Polymorphisms.

Background: Recent diabetes subclassifications have improved the differentiation between patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus despite several overlapping features, yet without considering genetic forms of diabetes. We sought to facilitate the identification of monogenic diabetes by creating a new tool that we validated in a pediatric maturity-onset diabetes of the young (MODY) cohort. Methods: We first created the DIAgnose MOnogenic DIAbetes (DIAMODIA) criteria based on the pre-existing, but incomplete, MODY calculator. This new score is composed of four strong and five weak criteria, with patients having to display at least one weak and one strong criterion. Results: The effectiveness of the DIAMODIA criteria was evaluated in two patient cohorts, the first consisting of patients with confirmed MODY diabetes (n=34) and the second of patients with T1DM (n=390). These DIAMODIA criteria successfully detected 100% of MODY patients. Multiple correspondence analysis performed on the MODY and T1DM cohorts enabled us to differentiate MODY patients from T1DM. The three most relevant variables to distinguish a MODY from T1DM profile were: lower insulin-dose adjusted A1c score ≤9, glycemic target-adjusted A1c score ≤4.5, and absence of three anti-islet cell autoantibodies. Conclusion: We validated the DIAMODIA criteria, as it effectively identified all monogenic diabetes patients (MODY cohort) and succeeded to differentiate T1DM from MODY patients. The creation of this new and effective tool is likely to facilitate the characterization and therapeutic management of patients with atypical diabetes, and promptly referring them for genetic testing which would markedly improve clinical care and counseling, as well.

Growth response of syndromic versus non-syndromic children born small for gestational age (SGA) to growth hormone therapy: a Belgian study.

Introduction: A substantial proportion of SGA patients present with a syndrome underlying their growth restriction. Most SGA cohorts comprise both syndromic and non-syndromic patients impeding delineation of the recombinant human growth hormone (rhGH) response. We present a detailed characterization of a SGA cohort and analyze rhGH response based on adult height (AH). Methods: Clinical and auxological data of SGA patients treated with rhGH, who had reached AH, were retrieved from BELGROW, a national database of all rhGH treated patients held by BESPEED (BElgian Society for PEdiatric Endocrinology and Diabetology). SGA patients were categorized in syndromic or non-syndromic patients. Results: 272 patients were included, 42 classified as syndromic (most frequent diagnosis (n=6): fetal alcohol syndrome and Silver-Russell syndrome). Compared with non-syndromic patients, syndromic were younger [years (median (P10/P90)] 7.43 (4.3/12.37) vs 10.21 (5.43/14.03), p=0.0005), shorter (height SDS -3.39 (-5.6/-2.62) vs -3.07 (-3.74/-2.62), p=0.0253) and thinner (BMI -1.70 (-3.67/0.04) vs -1.14 (-2.47/0.27) SDS, p=0.0054) at start of rhGH treatment. First year rhGH response was comparable (delta height SDS +0.54 (0.24/0.94) vs +0.56 (0.26/0.92), p=0.94). Growth pattern differed with syndromic patients having a higher prepubertal (SDS +1.26 vs +0.83, p=0.0048), but a lower pubertal height gain compared to the non-syndromic group (SDS -0.28 vs 0.44, p=0.0001). Mean rhGH dose was higher in syndromic SGA patients (mg/kg body weight/day 0.047 (0.039/0.064) vs 0.043 (0.035/0.056), p=0.0042). AH SDS was lower in syndromic SGA patients (-2.59 (-4.99/-1.57) vs -2.32 (-3.3/-1.2), p=0.0107). The majority in both groups remained short (<-2 SDS: syndromic 71%, non-syndromic 63%). Total height gain was comparable in both groups (delta height SDS +0.76 (-0.70/1.48) vs +0.86 (-0.12/1.86), p=0.41). Conclusions: Compared to non-syndromic SGA patients, syndromic SGA patients were shorter when starting rhGH therapy, started rhGH therapy earlier, and received a higher dose of rhGH. At AH, syndromic SGA patients were shorter than non-syndromic ones, but their height gain under rhGH therapy was comparable.

IGF1 haploinsufficiency in children with short stature: a case series.

CONTEXT: Short stature in children is a common reason for referral to pediatric endocrinologists. The underlying cause of short stature remains unclear in many cases and patients often receive unsatisfactory, descriptive diagnoses. While textbooks underline the rarity of genetic causes of growth hormone (GH) insensitivity and the severity of its associated growth failure, increased genetic testing in patients with short stature of unclear origin has revealed gene defects in the GH/insulin-like growth factor (IGF-I) axis associated with milder phenotypes. As such, heterozygous IGF1 gene defects have been reported as a cause of mild and severe short stature. Here, we aimed to describe the clinical and hormonal profile of children with IGF1 haploinsufficiency and their short-term response to growth hormone treatment (GHT). CASE DESCRIPTIONS: We describe five patients presenting with short stature, microcephaly, and in four out of five born small for gestational age diagnosed with IGF1 haploinsufficiency. The phenotype of these patients resembles that of previously described cases with similar gene defects. In our series, segregation of the short stature with the IGF1 deletion is evident from the pedigrees and our data suggests a modest response to GHT. CONCLUSIONS: This study is the first case series of complete heterozygous IGF1 deletions in children. The specific genetic defects provide a clear image of the phenotype of IGF1 haploinsufficiency - unbiased by heterozygous mutations with possible dominant negative effects on IGF-I function. We increase the evidence for IGF1 haploinsufficiency as a cause of short stature, microcephaly, and SGA.

A Novel Phenotype Combining Primary Ovarian Insufficiency Growth Retardation and Pilomatricomas With MCM8 Mutation.

CONTEXT: Primary Ovarian insufficiency (POI) affects 1% of women aged <40 years and leads most often to definitive infertility with adverse health outcomes. Very recently, genes involved in deoxyribonucleic acid (DNA) repair have been shown to cause POI. OBJECTIVE: To identify the cause of a familial POI in a consanguineous Turkish family. DESIGN: Exome sequencing was performed in the proposita and her mother. Chromosomal breaks were studied in lymphoblastoid cell lines treated with mitomycin (MMC). SETTING AND PATIENTS: The proposita presented intrauterine and postnatal growth retardation, multiple pilomatricomas in childhood, and primary amenorrhea. She was treated with growth hormone (GH) from age 14 to 18 years. RESULTS: We identified a novel nonsense variant in exon 9 of the minichromosome maintenance complex component 8 gene (MCM8) NM_001281522.1: c0.925C > T/p.R309* yielding either a truncated protein or nonsense-mediated messenger ribonucleic acid decay.The variant was homozygous in the daughter and heterozygous in the mother. MMC induced DNA breaks and aberrant metaphases in the patient's lymphoblastoid cells. The mother's cells had intermediate but significantly higher chromosomal breaks compared with a control. CONCLUSION: We describe a novel phenotype of syndromic POI related to a novel truncating MCM8 variant. We show for the first time that spontaneous tumors (pilomatricomas) are associated with an MCM8 genetic defect, making the screening of this gene necessary before starting GH therapy in patients with POI with short stature, especially in a familial or consanguineous context. Appropriate familial monitoring in the long term is necessary, and fertility preservation should be considered in heterozygous siblings to avoid rapid follicular atresia.

DNA Methylation Profiling and Genomic Analysis in 20 Children with Short Stature Who Were Born Small for Gestational Age.

PURPOSE: In a significant proportion of children born small for gestational age (SGA) with failure of catch-up growth, the etiology of short stature remains unclear after routine diagnostic workup. We wanted to investigate if extensive analysis of the (epi)genome can unravel the cause of growth failure in a significant portion of these children. PATIENTS AND METHODS: Twenty SGA children treated with GH because of short stature were selected from the BELGROW database of the Belgian Society for Pediatric Endocrinology and Diabetology for exome sequencing, single-nucleotide polymorphism (SNP) array and genome-wide methylation analysis to identify the (epi)genetic cause. First-year response to GH was compared with the response of SGA patients in the KIGS database. RESULTS: We identified (likely) pathogenic variants in 4 children (from 3 families) using exome sequencing and found pathogenic copy number variants in 2 probands using SNP array. In a child harboring a NSD1-containing microduplication, we identified a DNA methylation signature that is opposite to the genome-wide DNA methylation signature of Sotos syndrome. Moreover, we observed multilocus imprinting disturbances in 2 children in whom no other genomic alteration could be identified. Five of 6 children with a genetic diagnosis had an "above average" response to GH. CONCLUSIONS: The study indicates that a more advanced approach with deep genotyping can unravel unexpected (epi)genomic alterations in SGA children with persistent growth failure. Most SGA children with a genetic diagnosis had a good response to GH treatment.

Long-term mortality after childhood growth hormone treatment: the SAGhE cohort study.

BACKGROUND: Recombinant human growth hormone has been used for more than 30 years and its indications have increased worldwide. There is concern that this treatment might increase mortality, but published data are scarce. We present data from the entire dataset of all eight countries of the Safety and Appropriateness of Growth hormone treatments in Europe (SAGhE) consortium, with the aim of studying long-term overall and cause-specific mortality in young adult patients treated with recombinant human growth hormone during childhood and relating this to the underlying diagnosis. METHODS: This cohort study was done in eight European countries (Belgium, France, Germany, Italy, The Netherlands, Sweden, Switzerland, and the UK). Patients were classified a priori based on pre-treatment perceived mortality risk from their underlying disease and followed up for cause-specific mortality. Person-years at risk of mortality and expected rates from general population data were used to calculate standardised mortality ratios (SMRs). FINDINGS: The cohort comprised 24 232 patients treated with recombinant human growth hormone during childhood, with more than 400 000 patient-years of follow-up. In low-risk patients with isolated growth hormone deficiency or idiopathic short stature, all-cause mortality was not significantly increased (SMR 1·1, 95% CI 0·9-1·3). In children born small for gestational age, all-cause mortality was significantly increased when analysed for all countries (SMR 1·5, CI 1·1-1·9), but this result was driven by the French subcohort. In patients at moderate or high risk, mortality was increased (SMR 3·8, 3·3-4·4; and 17·1, 15·6-18·7, respectively). Mortality was not associated with mean daily or cumulative doses of recombinant human growth hormone for any of the risk groups. Cause-specific mortality from diseases of the circulatory and haematological systems was increased in all risk groups. INTERPRETATION: In this cohort, the largest, to our knowledge, with long-term follow-up of patients treated with recombinant human growth hormone during childhood, all-cause mortality was associated with underlying diagnosis. In patients with isolated growth hormone deficiency or idiopathic short stature, recombinant human growth hormone treatment was not associated with increased all-cause mortality. However, mortality from certain causes was increased, emphasising the need for further long-term surveillance. FUNDING: European Union.

Risk of Meningioma in European Patients Treated With Growth Hormone in Childhood: Results From the SAGhE Cohort.

Context: There has been concern that GH treatment of children might increase meningioma risk. Results of published studies have been inconsistent and limited. Objective: To examine meningioma risks in relation to GH treatment. Design: Cohort study with follow-up via cancer registries and other registers. Setting: Population-based. Patients: A cohort of 10,403 patients treated in childhood with recombinant GH in five European countries since this treatment was first used in 1984. Expected rates from national cancer registration statistics. Main Outcome Measures: Risk of meningioma incidence. Results: During follow-up, 38 meningiomas occurred. Meningioma risk was greatly raised in the cohort overall [standardized incidence ratio (SIR) = 75.4; 95% CI: 54.9 to 103.6], as a consequence of high risk in subjects who had received radiotherapy for underlying malignancy (SIR = 658.4; 95% CI: 460.4 to 941.7). Risk was not significantly raised in patients who did not receive radiotherapy. Risk in radiotherapy-treated patients was not significantly related to mean daily dose of GH, duration of GH treatment, or cumulative dose of GH. Conclusions: Our data add to evidence of very high risk of meningioma in patients treated in childhood with GH after cranial radiotherapy, but suggest that GH may not affect radiotherapy-related risk, and that there is no material raised risk of meningioma in GH-treated patients who did not receive radiotherapy.

Growth hormone treatment and fat redistribution in children born small for gestational age.

OBJECTIVE: To determine whether in children born small for gestational age (SGA) high-dose growth hormone (GH) treatment is not only associated with catch-up of growth and with gain of lean mass, but also with a more central fat distribution. STUDY DESIGN: Short children who were SGA (n = 25; age [mean +/- SD], 5.3 +/- 1.5 years) were randomly assigned to remain untreated (n = 14) or to receive GH (n = 11; sc 66 mug/Kg/d). Growth status and body composition were assessed at the study's start, after 1 year, and after 2 years with anthropometry and absorptiometry. RESULTS: Children who were treated with GH gained more height and weight than children who were untreated and developed a less adipose body composition (all P < .0001), as expected. However, these changes were also accompanied by a relatively more centripetal distribution of fat mass (0-2 year change in ratio of trunk fat to limb fat; 0.26 +/- 0.23 versus 0.02 +/- 0.15; P < .0001). CONCLUSION: In children who are SGA, catch-up growth induced by exogenous GH in high doses is accompanied by a less adipose body composition and a more central fat distribution.

Intrathoracic lymphadenitis caused by Mycobacterium avium and Mycobacterium tuberculosis in an immunocompetent child.

By means of a DNA probe assay (INNO-LiPA) we identified 2 different mycobacterial strains (Mycobacterium avium and Mycobacterium tuberculosis complex) from a mediastinal lymph node biopsy obtained from an apparently immunocompetent 7.5-year-old girl, whereas culture grew only M. avium. Clinicians should be aware of the possible occurrence of mixed infection involving both nontuberculous mycobacteria and M. tuberculosis.

Neonatal cholestatic jaundice as the first symptom of a mutation in the hepatocyte nuclear factor-1beta gene (HNF-1beta).

This report describes the phenotype of a novel de novo heterozygous frameshift mutation in the hepatocyte nuclear factor-1beta gene (HNF-1beta or TCF2) manifest as a neonatal paucity of intrahepatic bile ducts. HNF-1beta mutations should be considered in neonates with cholestatic jaundice associated with renal malformation or diabetes mellitus.

Cancer Risks in Patients Treated With Growth Hormone in Childhood: The SAGhE European Cohort Study.

Context: Growth hormone (GH) is prescribed for an increasing range of indications, but there has been concern that it might raise cancer risk. Published data are limited. Objective: To examine cancer risks in relation to GH treatment. Design: Cohort study. Setting: Population-based. Patients: Cohort of 23,984 patients treated with recombinant human GH (r-hGH) in eight European countries since this treatment was first used in 1984. Cancer expectations from country-specific national population statistics. Main Outcome Measures: Cancer incidence and cancer mortality. Results: Incidence and mortality risks in the cohort were raised for several cancer sites, largely consequent on second primary malignancies in patients given r-hGH after cancer treatment. There was no clear raised risk in patients with growth failure without other major disease. Only for bone and bladder cancers was incidence significantly raised in GH-treated patients without previous cancer. Cancer risk was unrelated to duration or cumulative dose of r-hGH treatment, but for patients treated after previous cancer, cancer mortality risk increased significantly with increasing daily r-hGH dose (P trend < 0.001). Hodgkin lymphoma (HL) incidence increased significantly with longer follow-up (P trend = 0.001 for patients overall and 0.002 for patients without previous cancer). Conclusions: Our results do not generally support a carcinogenic effect of r-hGH, but the unexplained trend in cancer mortality risk in relation to GH dose in patients with previous cancer, and the indication of possible effects on bone cancer, bladder cancer, and HL risks, need further investigation.

Expanding the CHARGE Geno-Phenotype: A Girl with Novel CHD7 Deletion, Hypogonadotropic Hypogonadism, and Agenesis of Uterus and Ovaries.

BACKGROUND: CHARGE syndrome is a variable entity. Clinical diagnosis is based on the Blake-Verloes criteria and can be confirmed by identifying a mutation or deletion in the CHD7 gene. Hypoplasia of the male genitalia and lack or incomplete secondary sexual development in both sexes is a common feature, and is most often attributable to hypogonadotropic hypogonadism which is described in >80% of the CHARGE patients. Other genital anomalies in CHARGE patients are rare. METHODS AND RESULTS: We describe the case of a girl with a novel heterozygous deletion in exon 15 of the CHD7 gene and combined agenesis of uterus and ovaries, besides gonadotropin deficiency, thus expanding the geno-phenotype of CHARGE syndrome. CONCLUSION: In case of persistent primary amenorrhea, despite estrogen replacement, this unusual combination should be considered in girls with CHARGE syndrome.

High unacylated ghrelin levels support the concept of anorexia in infants with prader-willi syndrome.

BACKGROUND: Prader-Willi syndrome (PWS) is a rare genetic neurodevelopmental disorder with different nutritional phases from suckling deficit with failure to thrive to early onset of obesity. Hyperghrelinemia has been described in PWS long before the development of obesity. Ghrelin is found in both acylated (AG) and unacylated (UAG) forms in the circulation. In contrast to AG, UAG has been shown to inhibit food intake and to be elevated in anorexia nervosa. The present project is aiming to determine the underlying mechanisms driving the different nutritional phases in PWS. METHODS: Measurement of at least 4 h-fasting plasma acylated and unacylated ghrelin in 37 infants with a genetic diagnosis of PWS aged from 1 month to 4 years and in 100 age-matched controls without endocrine disorder recruited prior to minor surgery. One blood sampling was analysed for each patient/control and clinical data were recorded. Eleven PWS infants underwent repetitive blood samples at 3 or 6-month intervals during routine visits. RESULTS: In infants with PWS, AG is not elevated (p = 0.45), UAG is significantly higher (p = 0.0044; confidence interval 1.06;1.33) resulting in a low AG/UAG ratio (p = 0.0056; confidence interval 0.76;0.95) compared to controls. CONCLUSION: Unlike children and adults with PWS that have high AG and AG/UAG ratio, infants with PWS have elevated UAG that supports the concept of anorexia in the early phases of the disease. The change in AG/UAG ratio possibly drives the switch from failure to thrive to obesity. CLINICAL TRIAL REGISTRATION: NCT02529085 .

Congenital isolated adrenocorticotropin deficiency: an underestimated cause of neonatal death, explained by TPIT gene mutations.

Tpit is a T box transcription factor important for terminal differentiation of pituitary proopiomelanocortin-expressing cells. We demonstrated that human and mouse mutations of the TPIT gene cause a neonatal-onset form of congenital isolated ACTH deficiency (IAD). In the absence of glucocorticoid replacement, IAD can lead to neonatal death by acute adrenal insufficiency. This clinical entity was not previously well characterized because of the small number of published cases. Since identification of the first TPIT mutations, we have enlarged our series of neonatal IAD patients to 27 patients from 21 unrelated families. We found TPIT mutations in 17 of 27 patients. We identified 10 different TPIT mutations, with one mutation found in five unrelated families. All patients appeared to be homozygous or compound heterozygous for TPIT mutations, and their unaffected parents are heterozygous carriers, confirming a recessive mode of transmission. We compared the clinical and biological phenotype of the 17 IAD patients carrying a TPIT mutation with the 10 IAD patients with normal TPIT-coding sequences. This series of neonatal IAD patients revealed a highly homogeneous clinical presentation, suggesting that this disease may be an underestimated cause of neonatal death. Identification of TPIT gene mutations as the principal molecular cause of neonatal IAD permits prenatal diagnosis for families at risk for the purpose of early glucocorticoid replacement therapy.

Insulin sensitivity modulates the growth response during the first year of high-dose growth hormone treatment in short prepubertal children born small for gestational age.

AIM: To study the relationship between insulin sensitivity and growth response in short children born small for gestational age (SGA) treated with growth hormone (GH). METHODS: Randomized, open-label, 24-month intervention study in 40 short prepubertal SGA children [age (mean ± SD) 5.3 ± 1.5 years], who either remained untreated (n = 20) or were treated with GH (66 µg/kg/day; n = 20). Changes in fasting glucose, insulin, quantitative insulin sensitivity check index (QUICKI), IGF-1 and leptin after 1 and 2 years were studied. RESULTS: Mean height SDS increased from -3.3 ± 0.7 to -2.3 ± 0.7 after 1 year, and to -1.9 ± 0.7 after 2 years of treatment. QUICKI decreased significantly (p = 0.008) in the first year of GH treatment and stabilized in the second year. Baseline QUICKI was positively associated (r = 0.40; p < 0.05) with the change in height SDS in the first year. CONCLUSION: Higher insulin sensitivity at the start of GH therapy is associated with greater first-year growth response to GH, and could be a promising parameter in selecting prepubertal short SGA children for GH treatment. However, this finding needs to be confirmed in larger studies.

Rhabdomyolysis in diabetic ketoacidosis.

Rhabdomyolysis is a potentially lethal disorder, characterized by elevated serum concentrations of creatine kinase (CK) due to skeletal muscle injury. In this paper a patient with diabetic ketoacidosis (DKA) is reported who developed rhabdomyolysis (maximum CK level, 37,700 U/L; normal, < 170 U/L), anemia (6.2 g/dL) and thrombocytopenia (16,000/microL). This combination of rhabdomyolysis with anemia and thrombocytopenia has not yet been reported in DKA. The pathogenic mechanism leading to rhabdomyolysis in DKA remains unsettled. From the literature it seems that those patients who develop rhabdomyolysis have very high glucose levels and a high osmolality on admission. Low phosphate levels can play a role as well. The etiology of anemia and thrombocytopenia in our patient remains obscure. Intravascular hemolysis could not be demonstrated but intramedullar hemolysis, due to osmolar shift or hypophosphatemia, cannot be excluded. A review of the literature data revealed that rhabdomyolysis is not so uncommon in DKA. However, to obtain incidence data in children, prospective studies are necessary.