A. S. Paul van Trotsenburg

Efficacy and Safety of Statin Therapy in Children With Familial Hypercholesterolemia A Randomized, Double-Blind, Placebo-Controlled Trial With Simvastatin

Background—A multicenter, randomized, double-blind, placebo-controlled study was conducted to evaluate LDL cholesterol–lowering efficacy, overall safety, and tolerability and the influence on growth and pubertal development of simvastatin in a large cohort of boys and girls with heterozygous familial hypercholesterolemia (heFH). Methods and Results—A total of 173 heFH children (98 boys and 75 girls) were included in this study. After a 4-week diet/placebo run-in period, children with heFH were randomized to either simvastatin or placebo in a ratio of 3:2. Simvastatin was started at 10 mg/d and titrated at 8-week intervals to 20 and then 40 mg/d. During a 24-week extension period, the patients continued to receive simvastatin (40 mg) or placebo according to their assignment. After 48 weeks of simvastatin therapy, there were significant reductions of LDL cholesterol (−41%), total cholesterol (−31%), apolipoprotein B (−34%), VLDL cholesterol (−21%), and triglyceride (−9%) levels. HDL cholesterol and apolipoprotein A-I levels were increased by 3.3% and 10.4%, respectively (not significant). No safety issues became evident. Except for small decreases in dehydroepiandrosterone sulfate compared with placebo, there were no significant changes from baseline in adrenal, gonadal, and pituitary hormones in either treatment group. Conclusions—Simvastatin significantly reduced LDL cholesterol, total cholesterol, triglyceride, VLDL cholesterol, and apolipoprotein B levels and was well tolerated in children with heFH. There was no evidence of any adverse effect of simvastatin on growth and pubertal development. Therefore, simvastatin at doses up to 40 mg is a well-tolerated and effective therapy for heFH children.

Statin treatment in children with familial hypercholesterolemia - The younger, the better

Background— We previously demonstrated in a randomized placebo-controlled trial that 2-year pravastatin treatment induced a significant regression of carotid intima-media thickness (IMT) in 8- to 18-year-old children with familial hypercholesterolemia. Subsequently, we continued to follow up these children to explore the relation between the age of statin initiation and carotid IMT after follow-up on statin treatment. We also examined safety aspects of statin therapy during this long-term follow-up. Methods and Results— All 214 children who initially participated in the previous placebo-controlled study were eligible for the follow-up study. After completion of the placebo-controlled study, all children continued treatment with pravastatin 20 or 40 mg, depending on their age. Blood samples were taken on a regular basis for lipids and safety parameters, and a carotid IMT measurement was performed after an average treatment period of 4.5 years. Follow-up data for 186 children were available for the statistical analyses. Multivariate analyses revealed that age at statin initiation was an independent predictor for carotid IMT after follow-up with adjustment for carotid IMT at initiation of statin treatment, sex, and duration of treatment. Early initiation of statin treatment was associated with a subsequently smaller IMT. Furthermore, no serious laboratory adverse events were reported during follow-up, and statin treatment had no untoward effects on sexual maturation. Conclusions— These data indicate that early initiation of statin treatment delays the progression of carotid IMT in adolescents and young adults. The present study shows for the first time that early initiation of statin therapy in children with familial hypercholesterolemia might be beneficial in the prevention of atherosclerosis in adolescence.

Loss-of-function mutations in IGSF1 cause an X-linked syndrome of central hypothyroidism and testicular enlargement

Congenital central hypothyroidism occurs either in isolation or in conjunction with other pituitary hormone deficits. Using exome and candidate gene sequencing, we identified 8 distinct mutations and 2 deletions in IGSF1 in males from 11 unrelated families with central hypothyroidism, testicular enlargement and variably low prolactin concentrations. IGSF1 is a membrane glycoprotein that is highly expressed in the anterior pituitary gland, and the identified mutations impair its trafficking to the cell surface in heterologous cells. Igsf1-deficient male mice show diminished pituitary and serum thyroid-stimulating hormone (TSH) concentrations, reduced pituitary thyrotropin-releasing hormone (TRH) receptor expression, decreased triiodothyronine concentrations and increased body mass. Collectively, our observations delineate a new X-linked disorder in which loss-of-function mutations in IGSF1 cause central hypothyroidism, likely secondary to an associated impairment in pituitary TRH signaling.

Beneficial Effects of Growth Hormone Treatment on Cognition in Children with Prader-Willi Syndrome: A Randomized Controlled Trial and Longitudinal Study

BACKGROUND Knowledge about the effects of GH treatment on cognitive functioning in children with Prader-Willi syndrome (PWS) is limited. METHODS Fifty prepubertal children aged 3.5 to 14 yr were studied in a randomized controlled GH trial during 2 yr, followed by a longitudinal study during 4 yr of GH treatment. Cognitive functioning was measured biennially by short forms of the WPPSI-R or WISC-R, depending on age. Total IQ (TIQ) score was estimated based on two subtest scores. RESULTS During the randomized controlled trial, mean sd scores of all subtests and mean TIQ score remained similar compared to baseline in GH-treated children with PWS, whereas in untreated controls mean subtest sd scores and mean TIQ score decreased and became lower compared to baseline. This decline was significant for the Similarities (P = 0.04) and Vocabulary (P = 0.03) subtests. After 4 yr of GH treatment, mean sd scores on the Similarities and Block design subtests were significantly higher than at baseline (P = 0.01 and P = 0.03, respectively), and scores on Vocabulary and TIQ remained similar compared to baseline. At baseline, children with a maternal uniparental disomy had a significantly lower score on the Block design subtest (P = 0.01) but a larger increment on this subtest during 4 yr of GH treatment than children with a deletion. Lower baseline scores correlated significantly with higher increases in Similarities (P = 0.04) and Block design (P < 0.0001) sd scores. CONCLUSIONS Our study shows that GH treatment prevents deterioration of certain cognitive skills in children with PWS on the short term and significantly improves abstract reasoning and visuospatial skills during 4 yr of GH treatment. Furthermore, children with a greater deficit had more benefit from GH treatment.

Efficacy and safety of oxandrolone in growth hormone-treated girls with turner syndrome.

CONTEXT AND OBJECTIVE GH therapy increases growth and adult height in Turner syndrome (TS). The benefit to risk ratio of adding the weak androgen oxandrolone (Ox) to GH is unclear. DESIGN AND PARTICIPANTS A randomized, placebo-controlled, double-blind, dose-response study was performed in 10 centers in The Netherlands. One hundred thirty-three patients with TS were included in age group 1 (2-7.99 yr), 2 (8-11.99 yr), or 3 (12-15.99 yr). Patients were treated with GH (1.33 mg/m(2) . d) from baseline, combined with placebo (Pl) or Ox in low (0.03 mg/kg . d) or conventional (0.06 mg/kg . d) dose from the age of 8 yr and estrogens from the age of 12 yr. Adult height gain (adult height minus predicted adult height) and safety parameters were systematically assessed. RESULTS Compared with GH+Pl, GH+Ox 0.03 increased adult height gain in the intention-to-treat analysis (mean +/- sd, 9.5 +/- 4.7 vs. 7.2 +/- 4.0 cm, P = 0.02) and per-protocol analysis (9.8 +/- 4.9 vs. 6.8 +/- 4.4 cm, P = 0.02). Partly due to accelerated bone maturation (P < 0.001), adult height gain on GH+Ox 0.06 was not significantly different from that on GH+Pl (8.3 +/- 4.7 vs. 7.2 +/- 4.0 cm, P = 0.3). Breast development was slower on GH+Ox (GH+Ox 0.03, P = 0.02; GH+Ox 0.06, P = 0.05), and more girls reported virilization on GH+Ox 0.06 than on GH+Pl (P < 0.001). CONCLUSIONS In GH-treated girls with TS, we discourage the use of the conventional Ox dosage (0.06 mg/kg . d) because of its low benefit to risk ratio. The addition of Ox 0.03 mg/kg . d modestly increases adult height gain and has a fairly good safety profile, except for some deceleration of breast development.

Comorbidity, Hospitalization, and Medication Use and Their Influence on Mental and Motor Development of Young Infants With Down Syndrome

OBJECTIVE. Young infants with Down syndrome have an increased occurrence of several well-known medical conditions such as congenital heart and gastrointestinal disease. The aim of this study was to establish consequences like hospitalization and medication use rates and to determine their possible influence on early neurodevelopment. PATIENTS AND METHODS. This study compared 2 years of thyroxine treatment with placebo in 196 neonates with Down syndrome who were included in a previously reported randomized clinical trial. Parents were interviewed about comorbidity, hospitalization, and medication use at random assignment and regularly thereafter. Data were cross-checked with discharge letters when available. The influence of comorbidity on neurodevelopment at 2 years old (Bayley Scales of Infant Development II) was determined by stepwise multiple linear-regression analysis. RESULTS. Before trial entry, 163 infants with Down syndrome had been admitted to hospital for an average of 14.01 days, whereas during the trial, 95 of 181 infants who completed the trial were hospitalized for an average 19.75 days. Main hospitalization reasons during the trial were lung/airway and congenital heart and gastrointestinal disease. The 48 infants operated on for heart or gastrointestinal disease accounted for 1401 of the total number of 1876 hospital admission days during the trial and for 33 of 62 admissions for lung/airway infection. During their second year of life, ∼60% of the infants were prescribed drugs, mostly antibiotics and pulmonary. Regression analysis showed infantile spasms, “other” central nervous system disease, and gastrointestinal disease necessitating surgery to be associated with greater developmental age delays at 24 months old (mental: 6.87, 3.52, and 1.69 months; and motor: 3.59, 2.54, and 1.68 months, respectively). CONCLUSIONS. Hospital admission and medication use rates in young infants with Down syndrome are still very high, mainly because of congenital heart and gastrointestinal disease and acquired respiratory disease. Central nervous system disease and gastrointestinal disease necessitating surgery were independently associated with a worse developmental outcome.

Efficacy and Safety of Long-Term Continuous Growth Hormone Treatment in Children with Prader-Willi Syndrome

BACKGROUND Children with Prader-Willi syndrome (PWS) have abnormal body composition and impaired growth. Short-term GH treatment has beneficial effects. OBJECTIVES The aim of the study was to investigate effects of long-term continuous GH treatment on body composition, growth, bone maturation, and safety parameters. SETTING We conducted a multicenter prospective trial. DESIGN Fifty-five children with a mean +/- sd age of 5.9 +/- 3.2 yr were followed during 4 yr of continuous GH treatment (1 mg/m(2) . d). Data were annually obtained in one center: fat percentage (fat%) and lean body mass (LBM) by dual-energy x-ray absorptiometry, height, weight, head circumference, bone age, blood pressure, and fasting IGF-I, IGF binding protein-3, glucose, insulin, glycosylated hemoglobin, total cholesterol, high-density lipoprotein, and low-density lipoprotein. sd scores (SDS) were calculated according to Dutch and PWS reference values (SDS and SDS(PWS)). RESULTS Fat%SDS was significantly lower after 4 yr of GH treatment (P < 0.0001). LBMSDS significantly increased during the first year (P = 0.02) but returned to baseline values the second year and remained unchanged thereafter. Mean +/- sd height normalized from -2.27 +/- 1.2 SDS to -0.24 +/- 1.2 SDS (P < 0.0001). Head circumference SDS increased from -0.79 +/- 1.0 at start to 0.07 +/- 1.1 SDS after 4 yr. BMISDS(PWS) significantly decreased. Mean +/- sd IGF-I and the IGF-I/IGF binding protein-3 ratio significantly increased to 2.08 +/- 1.1 and 2.32 +/- 0.9 SDS, respectively. GH treatment had no adverse effects on bone maturation, blood pressure, glucose homeostasis, and serum lipids. CONCLUSIONS Our study in children with PWS shows that 4 yr of continuous GH treatment (1 mg/m(2) . d) improves body composition by decreasing fat%SDS and stabilizing LBMSDS and head circumference SDS and normalizes heightSDS without adverse effects. Thus, long-term continuous GH treatment is an effective and safe therapy for children with PWS.

Prevalence and risk factors of radiation-induced growth hormone deficiency in childhood cancer survivors: A systematic review

BACKGROUND Growth hormone deficiency (GHD) is usually the first and most frequent endocrine problem occurring after cranial radiotherapy (CRT). The aim of this systematic review was to evaluate the existing evidence of the prevalence and risk factors of radiation-induced GHD in childhood cancer survivors. METHODS MEDLINE, EMBASE and CENTRAL were searched for studies reporting on radiation-induced GHD in childhood cancer survivors. Information about study characteristics, prevalence and risk factors was abstracted and the quality of each study was assessed. A meta-regression analysis was performed. RESULTS The prevalence of radiation-induced GHD was estimated in 33 studies. Most studies had methodological limitations. The prevalence varied considerably between 0% and 90.9%. Selecting only the studies with adequate peak GH cut-off limits (<5 microg/L) resulted in 3 studies. In these studies the prevalence ranged from 29.0% to 39.1%, with a pooled prevalence of 35.6%. Higher CRT dose and longer follow-up time have been suggested to be the main risk factors of GHD by studies included in this review. The meta-regression analysis showed that the wide variation in the prevalence of GHD could be explained by differences in maximal CRT dose. CONCLUSIONS GHD is a frequent consequence after CRT in childhood cancer survivors. The prevalence of radiation-induced GHD ranged from 29.0% to 39.1% when selecting only studies with adequate peak GH cut-off limits. Higher CRT dose and longer follow-up time are the main risk factors. More well-designed studies are needed to accurately estimate the prevalence of GHD and to define the exact CRT threshold dose.

The ambiguous role of NKX2-5 mutations in thyroid dysgenesis.

NKX2-5 is a homeodomain-containing transcription factor implied in both heart and thyroid development. Numerous mutations in NKX2-5 have been reported in individuals with congenital heart disease (CHD), but recently a select few have been associated with thyroid dysgenesis, among which the p.A119S variation. We sequenced NKX2-5 in 303 sporadic CHD patients and 38 families with at least two individuals with CHD. The p.A119S variation was identified in two unrelated patients: one was found in the proband of a family with four affected individuals with CHD and the other in a sporadic CHD patient. Clinical evaluation of heart and thyroid showed that the mutation did not segregate with CHD in the familial case, nor did any of the seven mutation carriers have thyroid abnormalities. We tested the functional consequences of the p.A119S variation in a cellular context by performing transactivation assays with promoters relevant for both heart and thyroid development in rat heart derived H10 cells and HELA cells. There was no difference between wildtype NKX2-5 and p.A119S NKX2-5 in activation of the investigated promoters in both cell lines. Additionally, we reviewed the current literature on the topic, showing that there is no clear evidence for a major pathogenic role of NKX2-5 mutations in thyroid dysgenesis. In conclusion, our study demonstrates that p.A119S does not cause CHD or TD and that it is a rare variation that behaves equal to wildtype NKX2-5. Furthermore, given the wealth of published evidence, we suggest that NKX2-5 mutations do not play a major pathogenic role in thyroid dysgenesis, and that genetic testing of NKX2-5 in TD is not warranted.

A specific mutation in TBL1XR1 causes Pierpont syndrome

Background The combination of developmental delay, facial characteristics, hearing loss and abnormal fat distribution in the distal limbs is known as Pierpont syndrome. The aim of the present study was to detect and study the cause of Pierpont syndrome. Methods We used whole-exome sequencing to analyse four unrelated individuals with Pierpont syndrome, and Sanger sequencing in two other unrelated affected individuals. Expression of mRNA of the wild-type candidate gene was analysed in human postmortem brain specimens, adipose tissue, muscle and liver. Expression of RNA in lymphocytes in patients and controls was additionally analysed. The variant protein was expressed in, and purified from, HEK293 cells to assess its effect on protein folding and function. Results We identified a single heterozygous missense variant, c.1337A>C (p.Tyr446Cys), in transducin β-like 1 X-linked receptor 1 (TBL1XR1) as disease-causing in all patients. TBL1XR1 mRNA expression was demonstrated in pituitary, hypothalamus, white and brown adipose tissue, muscle and liver. mRNA expression is lower in lymphocytes of two patients compared with the four controls. The mutant TBL1XR1 protein assembled correctly into the nuclear receptor corepressor (NCoR)/ silencing mediator for retinoid and thyroid receptors (SMRT) complex, suggesting a dominant-negative mechanism. This contrasts with loss-of-function germline TBL1XR1 deletions and other TBL1XR1 mutations that have been implicated in autism. However, autism is not present in individuals with Pierpont syndrome. Conclusions This study identifies a specific TBL1XR1 mutation as the cause of Pierpont syndrome. Deletions and other mutations in TBL1XR1 can cause autism. The marked differences between Pierpont patients with the p.Tyr446Cys mutation and individuals with other mutations and whole gene deletions indicate a specific, but as yet unknown, disease mechanism of the TBL1XR1 p.Tyr446Cys mutation.