Dominique Beckers

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.).

Growth Hormone (GH) Secretion in Patients with Childhood-Onset GH Deficiency: Retesting after One Year of Therapy and at Final Height

Background: Recent studies have shown that many patients treated with growth hormone (GH) during childhood because of idiopathic GH deficiency (GHD) are no longer GH deficient when retested after cessation of GH therapy when final height is achieved. These patients are labelled as transient GHD. We hypothesized that normalization of GH secretion in transient GHD could occur earlier during the course of GH treatment, which could allow earlier cessation of GH treatment. Methods: In a retrospective study, GH secretion was re-evaluated after cessation of GH treatment at final height in 43 patients diagnosed during childhood as idiopathic GHD (10 with multiple pituitary hormonal deficiencies (MPHD) and 33 with isolated GHD (IsGHD)). In a prospective study, GH secretion was re-assessed after interruption of GH treatment given for 1 year in 18 children with idiopathic GHD (2 MPHD, 16 IsGHD). GH secretion was evaluated by glucagon or insulin stimulation tests. Results: In the retrospective study, all the 10 patients with MPHD and 64% of the 33 patients with IsGHD were still deficient at re-evaluation using the paediatric criteria to define GHD (GH peak <10 ng/ml at provocative test). The proportion of persisting deficiency was greater in patients with complete IsGHD (86%, 12/14 patients) than in patients with partial IsGHD (47%, 9/19 patients). With the criteria proposed in adulthood (GH peak <3 ng/ml), all the 10 patients with MPHD were still considered to be deficient. In contrast, only 15% (5/33 patients) with IsGHD had a maximal GH value <3 ng/ml (36% of the 14 patients with complete IsGHD and none of the 19 patients with partial IsGHD). In the prospective study, after interruption of GH therapy given for 1 year, the 2 patients with MPHD were still GHD at re-evaluation and they resumed GH treatment. Among the 16 patients with IsGHD, 13 (81%) were still deficient (peak response <10 ng/ml) after 1 year. Two of the 3 patients in whom GHD was not confirmed at retesting after 1 year GH showed again a deficient response at second retesting. Conclusions: Although many patients diagnosed with IsGHD during childhood have a normalized GH secretory capacity when retested during adulthood, early retesting after interruption of GH treatment given for 1 year during childhood does not enable to determine if GH therapy has to be discontinued before cessation of growth.

Adult final height after GH therapy for irradiation-induced GH deficiency in childhood survivors of brain tumors : the Belgian experience

OBJECTIVES The treatment of brain tumors in childhood is frequently complicated by growth retardation with a high proportion of irradiation (Irr)-induced GH deficiency (GHD) resulting in reduced adult final height (AFH) even after GH therapy (GHT). In order to optimize future GHT protocols, more information on the factors influencing the growth response to GH in these children is needed. This retrospective study evaluated AFH and influencing auxological and treatment factors of a standardized daily biosynthetic GHT in childhood survivors of brain tumors with documented GHD after brain Irr. DESIGN AND METHODS From the Belgian GH Registry, 57 children survivors of a brain tumor outside the hypothalamo-pituitary area with available AFH were stratified into two groups depending on cranial (C-Irr; n=25) or craniospinal (CS-Irr; n=32) Irr. RESULTS In the C-Irr patients, results showed an AFH of -0.8 (-2.5, 1.4) SDS (median (range)) and in the CS-Irr patients, results showed a significantly (P<0.001) lower AFH of -1.8 (-4.2, 0.0) SDS. AFH SDS corrected for mid-parental height (MPH) in the C-Irr group was -0.5 (-2.2, 0.9) and -1.5 (-3.6, 0.0) SDS in the CS-Irr group. AFH was positively correlated with age at end of tumor therapy, height SDS at start GHT, height gain SDS first year GHT, and negatively correlated with CS-Irr. CONCLUSIONS GHT failed to restore adult height to MPH in nearly half of Irr-induced GHD patients for brain tumor, especially those receiving CS-Irr, irradiated at a younger age or shorter at start GHT.

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.

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 studys 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.

Concerns, expectations and perception regarding stature, physical appearance and psychosocial functioning before and during high-dose growth hormone treatment of short pre-pubertal children born small for gestational age

Background/Aims: Few data are available about parental concerns and psychosocial functioning of young children born small for gestational age (SGA) treated with growth hormone (GH). The present study focused on the perception of short stature and the concerns and expectations of the parents regarding GH treatment. Methods: Forty prepubertal short SGA children, randomized into a GH-treated and a GH-untreated group, and their parents were evaluated by a questionnaire and a semi-structured interview at start and after 2 years of follow-up. Results: Before start, 85% of the parents were concerned about short stature, 76% expected an increase in adult height of ≧10 cm and 81% expected a positive impact on well-being. Half of the parents expressed fears regarding GH treatment. After 2 years, more parents of treated children reported obvious growth and physical changes, and fewer parents reported teasing because of short stature. An improvement of well-being was reported by half of the parents of treated and untreated children. Fears about GH treatment disappeared almost completely. Conclusion: The perspective of GH treatment induced major adult height expectations. In treated children, the physical effects of GH treatment became obvious, teasing because of short stature decreased and initial concerns about short stature and GH therapy decreased.

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.

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.

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.

Risk of meningioma in European patients treated with growth hormone in childhood: results from the SAGhE cohort.

Abstract 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.