Association analysis of ten candidate genes in a large multinational cohort of small for gestational age children and children with idiopathic short stature (NESTEGG study).

BACKGROUND: Fetal growth failure has been associated with an increased risk of hypertension, cardiovascular disease and diabetes in adulthood. Exploring the mechanisms underlying this association should improve our understanding of these common adult diseases. PATIENTS AND METHODS: We investigated 225 SNPs in 10 genes involved in growth and glucose metabolism (GH1, GHR, IGF1, IGF1R, STAT5A, STAT5B, MAPK1, MAPK3, PPARγ and INS) in 1,437 children from the multinational NESTEGG consortium: 345 patients born small for gestational age who remained short (SGA-S), 288 who showed catch-up growth (SGA-Cu), 410 idiopathic short stature (ISS) and 394 controls. We related genotype to pre- and/or postnatal growth parameters, response to growth hormone (if applicable) and blood pressure. RESULTS: We found several clinical associations for GH1, GHR, IGF1, IGF1R, PPARγ and MAPK1. One SNP remained significant after Bonferroni's correction: IGF1R SNP rs4966035's minor allele A was significantly more prevalent among SGA and associated with smaller birth length (p = 0.000378) and birth weight (weaker association), independent of gestational age. CONCLUSION: IGF1R SNP rs4966035 is significantly associated with birth length, independent of gestational age. This and other associations suggest that polymorphisms in these genes might partly explain the phenotype of short children born SGA and children with ISS.

Pediatric endocrine screening for von Hippel-Lindau disease: benefits and the challenge of compliance.

Fifteen children and adolescents (4 male) with a median age of 5.4 yr (range 1.2 -13.6 yr) were entered into a screening protocol to identify lesions of von Hippel-Lindau (VHL) disease. Fourteen had an affected first-degree relative and one had a previous VHL lesion. Screening during the period of 2000 to 2008 followed published guidelines and consisted of measurement of urinary catecholamines, adrenal and renal imaging and ophthalmological and central nervous system examinations and imaging. Screening identified 8 VHL lesions in 6 asymptomatic patients with confirmed genetic mutations. Five patients had elevated urinary noradrenaline excretion and in each case the presence of a pheochromocytoma was identified on adrenal magnetic resonance imagin scan. In one patient a left-sided tumor was identified 1 yr after a right-sided tumor had been removed. In a sixth patient a retinal capillary hemangioma and a cerebellar hemangioblastoma were identified. Patient compliance with the screening protocol was variable reflecting its time-intensive nature. A formal screening programme for this at-risk population of pediatric patients, despite being intensive, can identify VHL lesions during a pre-morbid phase and may thus have a beneficial impact on prognosis in this serious disorder.

Individualization of growth hormone therapy.

Short children born small for gestational age account for 20% of patients with short stature. These children should be investigated individually to identify treatable causes of their short stature and any associated neurodevelopmental problems. Randomized controlled growth hormone therapy trials demonstrate growth acceleration in childhood and improved adult height. The individualization of therapy is increasingly possible with insight from the available prediction models. These identify the main modifiable factors such as dose of growth hormone and age at the start of therapy. Non-modifiable factors including target height standard deviation score (SDS), weight SDS at the start of therapy, and first year response to therapy also play a significant role.

Clinical and endocrine features and long-term outcome of Graves' disease in early childhood.

Hyperthyroidism is rare in early childhood and most commonly caused by Graves' disease. We report 14 children (4 boys, 10 girls) aged 3.4-7.5 yr. At diagnosis, all patients had weight loss, hyperkinetic activity, tachycardia, difficulty sleeping, and poor concentration and 11 presented with proptosis. Four patients developed long-term neuropsychological problems. There was a family history in 7 cases. All patients had goiters, clinically assessed to be large and diffuse in 21%, medium-sized in 43%, and small in 36%. At diagnosis, height was increased with median (range) height; 1.25 standard deviation score (SDS) (-0.2-5.24) and body mass index (BMI) was decreased; -0.48 SDS (-1.65-1.26). Height and BMI SDS values were statistically different (p<0.032) Bone age was advanced in 4 of 5 children, who had assessments. Total or free T4 levels were elevated and TSH was undetectable. Ninety percent of patients (12/14) had positive thyroid peroxidase autoantibodies, mean level 680 IU/ml (range 50-1347). Initial treatment was with antithyroid medication using carbimazole; median dose 0.75 mg/kg/day (no.=13) or propylthiouracyl 15 mg/kg/day (no.=1). T4 was added in 6 patients. Normalisation of serum T4 occurred at 4 months (1- 9) and TSH at 7 months (3-24) after start of therapy. Treatment was discontinued after a minimum of 2 yr in 11 patients, relapse occurring in 9. Median duration of total therapy was 58 months (18-132). During adolescence, 4 patients had curative therapy by surgery (no.=2) or radioiodine (no.=2). In conclusion, disturbance of growth, behavioral difficulties and infrequent spontaneous remission are key features of Graves' disease in early childhood.

GH responsiveness in a large multinational cohort of SGA children with short stature (NESTEGG) is related to the exon 3 GHR polymorphism.

OBJECTIVE: The polymorphic deletion of exon 3 of the GH receptor (d3-GHR) has recently been linked to the magnitude of growth response to recombinant human GH (rhGH) therapy in short children with or without GH deficiency. We investigated this association in a large multinational cohort from the Network of European Studies of Genes in Growth (NESTEGG), comprising short children born small for gestational age (SGA). DESIGN: The study included short prepubertal SGA children treated with rhGH for 1 or 2 years. POPULATION: Two hundred and forty white Caucasian SGA children (138 male, 102 female) aged 6.6 +/- 2.3 years with a height at -3.0 +/- 0.7 SDS at start of rhGH treatment; 193 ethnically matched controls. METHODS: The GHR polymorphism (fl/fl, fl/d3 or d3/d3) was genotyped by polymerase chain reaction (PCR) multiplex assay. Growth velocity (G/V) in cm/year and changes in GV during the first and second year of rhGH treatment were evaluated. RESULTS: The change in GV was significantly greater in SGA children carrying one or two copies of the d3-GHR allele (P = 0.038 for the first year and P = 0.041 for the second year of GH treatment), but the change in height was not significantly different. Birthweight was significantly lower in SGA children with the d3/d3 genotype than in SGA children with the fl/fl genotype (P = 0.034) and in those with the fl/d3 genotype (P = 0.016). CONCLUSION: Our data, based on a large cohort, showed that the exon 3 GHR polymorphism is associated with responsiveness to rhGH treatment in SGA children with short stature.

Cosegregation of a novel homozygous CYP11B1 mutation with the phenotype of non-classical congenital adrenal hyperplasia in a consanguineous family.

We report a novel missense mutation of CYP11B1 causing non-classical 11beta-hydroxylase deficiency in 3 members of a consanguineous Turkish family. Two siblings presented with clinical evidence of precocious pseudopubarche. Biochemistry suggested 11beta-hydroxylase deficiency and genetic analysis revealed that they were homozygous for the missense mutation L489S within exon 9 of the CYP11B1 gene. The unaffected parents were heterozygotes for the same mutation. In addition, a paternal aunt of the affected siblings presenting with primary infertility and mild hirsutism was found to have the same homozygous mutation. This is the first report of a homozygous mutation in non-classical congenital adrenal hyperplasia that cosegregates with clinical phenotype. The significance of the missense mutation L489S in CYP11B1 is further supported by the conservation of leucine at position 489 in CYP11 genes in eleven other species. Molecular modelling of the enzyme suggests that the mutation L489S in CYP11B1 may alter the enzyme's substrate-binding affinity. These findings suggest that this homozygous mutation affects 11beta-hydroxylase function, resulting in the clinical features of non-classical adrenal hyperplasia in this family.

Benefits of screening in von Hippel-Lindau disease--comparison of morbidity associated with initial tumours in affected parents and children.

Von Hippel-Lindau (VHL) is a rare autosomal dominant syndrome characterised by the association of retinal and CNS haemangioblastomas, phaeochromocytoma and renal cell carcinoma. If a child of an affected parent has inherited a VHL mutation or the parent's mutation cannot be identified, then clinical screening is recommended. We report the clinical features in three parent-offspring pairs where the parents have presented clinically with renal cell carcinoma, phaeochromocytoma, cerebellar haemangioblastoma and retinal haemangioma, and the children have undergone pre-symptomatic screening. During the first screening a 13-year-old boy was diagnosed with bilateral phaeochromocytoma and later developed an endolymphatic sac tumour at 19 years. A right phaeochromocytoma was found in a 12-year-old girl who was screened from the age of 4 years and in a 13-year-old boy screened from 5 years of age. All children were asymptomatic at the time of diagnosis. These families demonstrate that clinical screening of children at risk of VHL can detect tumours before the first symptoms arise with a consequent reduction in morbidity. These observations strongly support the recommendation to undertake screening of the children of VHL patients.

Should recombinant human growth hormone therapy be used in short small for gestational age children?

Short small for gestational age (SGA) children represent 20% of all children with short stature and therefore constitute a significant portion of the caseload in a growth clinic. The recent approval of recombinant human growth hormone (GH) for the treatment of short stature in SGA children by the European Union's Committee on Proprietary Medicinal Products offers a new licensed therapeutic option. This article examines the role of GH therapy in short SGA children with particular reference to selection of patients, effectiveness, safety, and its potential metabolic implications.

Cushing's disease in childhood: presentation, investigation, treatment and long-term outcome.

Seventeen patients with Cushing's disease (CD) were treated from 1978 to 2000. There were 11 males and 6 females aged 6.8-18.8 years (mean age 13.0 +/- 5.9 years). Presenting features were: weight gain (100%); growth failure (71%); hirsutism (53%); striae (53%); hypertension (47%). Mean age of patients with striae was 15.2 +/- 2.3 years, without striae 10.3 +/- 3.3 years. Median height SDS was -1.81 (range -0.28 to -4.17), 53% having height SDS < -1.8. The height velocity in 6 subjects was subnormal (0.9-3.8 cm/year). Median BMI SDS was 2.29 (range 1.72-5.06). Cushing's disease was confirmed by detectable serum ACTH, median 28 ng/l (range 12-99, NR <10-50) (n = 15); loss of cortisol circadian rhythm values at midnight ranging from 216 to 1,080 nmol/l (NR <50) (n = 15); lack of cortisol suppression (NV < 50 nmol/l) during low-dose dexamethasone suppression test (LDDST) (0.5 mg 6-hourly x 8) (n = 14); and >50% suppression of cortisol compared with the basal value during high-dose dexamethasone suppression test (HDDST) (2 mg 6-hourly x 8) (n = 14). A CRH test (1 microg/kg i.v.) showed an increase of cortisol from 12 to 217% (median 73.5%) (n = 16). Pituitary imaging (CT/MRI) showed an image consistent with microadenoma in 6/17 patients, but there was concordance between pituitary imaging and surgical findings in 1/11 patients (9%). Inferior petrosal sinus sampling (IPSS) for ACTH after CRH was performed in 11 subjects (age 10.7-18.8 years). Central to peripheral ACTH ratios were >2 (2.5-157.2) in 10/11 patients. The inter-petrosal sinus ACTH gradient was >1.4 in 10 patients (2.1-20.8), indicating lateralization of ACTH secretion. In 10 patients (91%), the side of the tumour on IPSS was predictive of findings at surgery. Therapy consisted of transsphenoidal microadenomectomy (TSS) in 16 patients and bilateral adrenalectomy (1978) in 1. Following TSS alone, 7 patients were cured (cortisol <50 nmol/l) and 2 were in remission (cortisol <300 nmol/l), i.e. 56%. Seven had persisting hypercortisolaemia and underwent pituitary irradiation (4,500 cGy). Therapeutic outcome for a median of 8 years (0.5-24 years) resulted in cure of CD in 14/17 patients (82%) and remission in 1. Linear growth after TSS +/- pituitary irradiation in 10 subjects showed no short-term catch-up growth, with peak growth hormone (GH) 0.5-20.9 mU/l to insulin tolerance test (ITT)/glucagon. Eight patients were treated with human growth hormone (hGH) (14 U/m(2)/week) combined in 3 with GnRH analogue. The mean final (n = 6) or latest (n = 4) height SDS was -1.36. The difference between final/latest height SDS and target height SDS was 0.93 +/- 1.13, i.e. less (p = 0.005) than the difference between height SDS and target height SDS at presentation, i.e. 1.72 +/- 1.26, indicating long-term catch-up growth.

Investigating familial endocrine neoplasia syndromes in children.

Familial endocrine neoplasia syndromes multiple endocrine neoplasia (MEN) type 1, MEN type 2 and von Hippel Lindau (VHL) can now be diagnosed genetically in childhood. Paediatric endocrinologists must therefore be prepared to investigate and manage these children. This paper provides an overview of the major features of these syndromes and suggests protocols for regular screening of children known to be at risk of developing these disorders.

Growth hormone therapy and growth in children with Noonan's syndrome: results of 3 years' follow-up.

Growth data from the first 3 yr of a multicenter study examining the efficacy and safety of recombinant human GH [rhGH; 4 IU (1.3 mg)/m(2).day, sc] in children with Noonan's syndrome (NS) are reported for 23 subjects. Sixteen male and seven female patients (age, 9.3 +/- 2.6 yr at onset of GH therapy, mean +/- SD; range, 4.8-13.7) were each assessed at 1, 2, and 3 yr after starting treatment. Comparisons were made with a group of eight subjects (six males and two females, age, 9.0 +/- 4.1 yr; range, 4.1-14.8) with NS, not treated with rhGH, measured over the same period. All treated subjects underwent annual cardiac assessment. Height SD score increased from -2.7 +/- 0.4 at the start of GH therapy to -1.9 +/- 0.9 3 yr later (P < 0.001, two-tailed t test). This corresponded to an increase in height from 116.1 +/- 13.2 to 137.3 +/- 14.0 cm. Height velocity increased from 4.4 +/- 1.7 cm/yr in the year before treatment to 8.4 +/- 1.7 (P < 0.001), 6.2 +/- 1.7 (P < 0.001), and 5.8 +/- 1.8 (P = 0.01, two-tailed t test compared with baseline) during the first, second, and third years of GH treatment, respectively. Height acceleration was not significant during the second or third years when pubertal subjects were excluded. The comparison group showed an increase in height from 116.0 +/- 19.8 to 131.9 +/- 21.1 cm over the 3 yr (height SD score, -2.7 +/- 0.6 to -2.4 +/- 0.7, P = 0.3). None of the 23 children developed hypertrophic cardiomyopathy during GH treatment. The increase in growth rate in NS resulting from 1 yr of GH therapy seems to be maintained during the second year, although height velocity shows a less significant increase over pretherapy values. Possible abnormal anabolic effects of rhGH on myocardial thickness were not confirmed, and no treated patient developed features of hypertrophic cardiomyopathy.

Growth abnormalities associated with adrenal disorders and their management.

Linear growth can be disturbed in paediatric adrenal disease associated with endocrine hypo- or hyperfunction. Tall stature is a feature in some patients with adrenocorticotropic hormone resistance syndromes and short stature is recognized in the IMAGe (intrauterine growth retardation, metaphyseal dysplasia, adrenal hypoplasia congenita and genital anomalies) association. In autoimmune Addison's disease, growth is usually normal. In congenital adrenal hyperplasia, height may be compromised by advanced skeletal maturation or by suppressed growth, particularly in the neonatal period due to excess glucocorticoid treatment. In virilizing adrenal tumours, height is increased at diagnosis, but after surgical cure final height is usually in the normal range. In Cushing's disease, height was abnormally short in 50% of patients at presentation. After successful treatment, spontaneous catch-up growth was not seen. This led to a diagnosis of growth hormone (GH) deficiency in 80% of patients. With GH replacement, catch-up growth and long-term benefit occurred. Disturbance of linear growth is an important feature of many patients with adrenal disorders in childhood. Assessment of its pathogenesis and careful management are necessary to ensure optimal final adult height.

Analysis of the intracellular signalling domain of the human growth hormone receptor in children with idiopathic short stature.

OBJECTIVE: To investigate the hypothesis that intracellular, dominant-negative mutations of the growth hormone receptor (GHR) exist in children with idiopathic short stature (ISS) and partial growth hormone insensitivity (GHI). SUBJECTS: We studied 31 children aged 4.55-13.14 years with ISS (height

The insulin-like growth factor-I (IGF-I) gene in individuals born small for gestational age (SGA).

OBJECTIVE: To investigate the association of genetic variation of the insulin-like growth factor-I (IGF-I) gene with birth size small for gestational age (SGA). SUBJECTS: We have studied a cohort of 120 SGA patients and 147 appropriate for gestational age (AGA) controls from Haguenau, France. METHODS: PCR-SSCP analysis was performed to detect sequence variation in the coding region of the IGF-I gene. Microsatellite markers near the IGF-I gene (intronic and D12S78) were selected and amplified to perform further analysis by association studies. RESULTS: A novel polymorphism in intron 2 was discovered, but allele-specific PCR analysis in the 120 SGA patients and 147 AGA controls found no association between this polymorphism and birth size SGA. Chi squared (chi2) analysis found no statistically significant association between the allele distribution of the microsatellite markers in the SGA subjects and the AGA controls. Power calculations estimate that the D12S78 marker has an 80% chance of detecting a 10-15% difference. CONCLUSIONS: These studies suggest that genetic variation of IGF-I alone does not result in birth size small for gestational age in this population. Thus, if this gene influences fetal size, it plays only a minor role in a multifactorial disorder which involves other genetic and environmental factors.

Partial growth hormone insensitivity.

Partial growth hormone (GH) insensitivity can be defined as the clinical and biochemical features of IGF-I deficiency without GH deficiency and in the absence of the dysmorphic features of Laron syndrome. There is good evidence that this form of GH insensitivity exists, both in the context of severe GH resistance, and also in some patients with idiopathic short stature. The series of GH insensitivity patients in the European study shows a spectrum of clinical and biological defects, with several patients at the milder end of the spectrum having normal facies. The report of the presence of heterozygous mutations of the GH receptor in patients with idiopathic short stature has been confirmed by documentation of dominantly inherited mutations in familial short stature. Molecular screening in our unit of a group of 31 children with idiopathic short stature and normal GHBP, failed to identify mutations of the intracellular domain of the GH receptor. Consequently, although partial GH insensitivity is a proven entity, the clinical and biochemical identification of patients with GH resistance should precede molecular analysis. The analysis of individual patients and their families is more likely to reveal mutations, rather than a strategy of blanket molecular screening.

Bladder dysfunction and neurological disability at presentation in closed spina bifida.

Congenital closed spinal anomalies are associated with distortion of the spinal cord, the spinal nerve roots or both, and can result in neurological abnormalities of the lower limbs and neuropathic bladder dysfunction. This study reports clinical and videourodynamic findings in a group of 51 patients with closed spina bifida. The mean age at presentation to a specialist neurological clinic was 3.3 years. Twenty five patients presented with urinary tract disturbance and 12 presented with neurological problems. Thirty three had normal neurological examination or only minor objective signs, 21 had normal renal tract ultrasonography but only two patients had normal videourodynamics, with 31 having two or more abnormalities during this assessment. Neither clinical neurological assessment nor the history of voiding behaviour are reliable indicators of bladder dysfunction and subsequent risk of renal damage. Therefore, all patients with a known or suspected diagnosis of closed spina bifida should have videourodynamic assessment.