Growth hormone combined with child-specific motor training improves motor development in infants with Prader-Willi syndrome: a randomized controlled trial

Prader-Willi syndrome in a large sample from Spain: general features, obesity and regular use of psychotropic medication

BACKGROUND

Prader-Willi syndrome (PWS), a genetically determined disorder, the most frequent cause of early onset obesity, is associated with physical and cognitive dysfunctions and behavioural disturbances; these disturbances are frequently treated with psychotropic medication. The aim of this cross-sectional study was to describe the characteristics of the first large national sample of persons with PWS in Spain and analyse the relationships of those characteristics with key demographic and clinical factors, particularly with obesity and the regular use of psychotropic medication.

METHODS

Participants were recruited among all members of the Spanish Prader-Willi Association who agreed to take part in the study and fulfilled its inclusion criteria. Family and patient demographic features, family size and birth order, intelligence quotient (IQ), anthropometric measures, lifestyle habits, behavioural disturbances (with the Aberrant Behavior Checklist) and clinical data, as well as use of psychotropic drugs and their side effects (with the UKU scale), were collected in genetically confirmed cases of PWS. Bivariate and logistic regression analyses were used for determining the associations of demographic and clinical factors with both obesity and the regular use of psychotropic medication.

RESULTS

The cohort included 177 participants (aged 6-48 years), that is, 90 (50.8%) males and 87 (49.2%) females. Behavioural disturbances were present in a range of 75% to 93% of participants; psychotropic medication was prescribed to 81 (45.8%) of them. Number of siblings showed a direct correlation with IQ, especially among males, and inappropriate speech was more intense in only-child females. Obesity was, in parallel, strongly associated with ascending age and with not being currently under growth hormone (GH) treatment. Participants taking any psychotropic medication were characterised by more frequent age ≥30 years, high level of hyperactivity and a psychiatric diagnosis.

CONCLUSIONS

Characterisation of persons with PWS in Spain confirms their physical and behavioural phenotype and supports the long-term application of GH therapy and the rational use of psychotropic medication.

Early psychomotor development and growth hormone therapy in children with Prader-Willi syndrome: a review

Prader-Willi syndrome (PWS) is a rare genetic disorder caused by the loss of imprinted gene expression on the paternal chromosome 15q11-q13. PWS is characterized by varying degrees of early psychomotor developmental deficits, primarily in cognition, language, and motor development. This review summarizes the early mental cognitive development, language development, and motor development in patients with PWS, compares the correlation of genotype with phenotype, and provides an update regarding the effects and concerns related to potential main side effects of treatment with recombinant human growth hormone on early psycho-cognitive and motor function development along with the linear growth and body composition of children with PWS.Conclusion: Early psychomotor development is strongly correlated with the prognosis of patients with PWS; moreover, current studies support that the initiation of interventions at an early age can exert significant beneficial effects on enhancing the cognitive and linguistic development of patients with PWS and allow them to "catch up" with motor development.  What is Known: • Prader-Willi syndrome is a rare genetic disorder characterized by multisystem damage, and children with Prader-Willi syndrome are typically characterized by early developmental delays, specifically in the areas of cognitive and motor development. • Recombinant human growth hormone therapy is the only medical treatment approved for Prader-Willi syndrome. What is New: • Extensive presentation of psycho-cognitive and motor development features and genotype-phenotype correlation in children with Prader-Willi syndrome.  • The effects of growth hormone on early psychomotor development in children with Prader-Willi syndrome were thoroughly reviewed, including their short- and long-term outcomes and any associated adverse effects.

The standardization of the Polish version of the Alberta Infant Motor Scale

BACKGROUND

The Alberta Infant Motor Scale (AIMS) is a standardized tool for assessing gross motor development from birth through independent walking (0-18 months). The AIMS was developed, validated and standardized in the Canadian population. Results of previous studies on the standardization of the AIMS have discerned differences in some samples in comparison with Canadian norms. This study aimed to establish reference values of the AIMS for the Polish population and compare them to Canadian norms.

METHODS

The research involved 431 infants (219 girls, 212 boys, aged 0-<19 months), divided into nineteen age groups. The translated into Polish and validated version of the AIMS was used. The mean AIMS total scores and percentiles for every age group were calculated and compared with the Canadian reference values. Raw total AIMS scores were converted to 5th, 10th, 25th, 50th, 75th, and 90th percentiles. A one sample t-test was used to compare the AIMS total scores between Polish and Canadian infants (p-value < 0.05). A binomial test was performed to compare percentiles (p-value < 0.05).

RESULTS

The mean AIMS total scores in the Polish population were significantly lower in the seven age groups: 0-<1, 1-<2, 4-<5, 5-<6, 6-<7, 13-<14, and 15-<16 months of age (with small to large effect size). A few significant differences were found in the comparison of percentile ranks, mostly in the 75th percentile.

CONCLUSION

Our study provides the norms for the Polish AIMS version. According to differences in the mean AIMS total scores and percentiles, the original Canadian reference values are not congruent for Polish infants.

TRIAL REGISTRATION

ClinicalTrials.gov ID NCT05264064. URL https://clinicaltrials.gov/ct2/show/NCT05264064 . Date of registration: 03/03/2022.

Early recombinant human growth hormone treatment improves mental development and alleviates deterioration of motor function in infants and young children with Prader-Willi syndrome

BACKGROUND

Recombinant human growth hormone (rhGH) therapy has shown to improve height and body composition in children with Prader-Willi syndrome (PWS), the evidence of early rhGH treatment on motor and mental development is still accumulating. This study explored the time effect on psychomotor development, anthropometric indexes, and safety for infants and young children with PWS.

METHODS

A phase 3, single-arm, multicenter, self-controlled study was conducted in six sites. Patients received rhGH at 0.5 mg/m2/day for first four weeks, and 1 mg/m2/day thereafter for up to 52 weeks. Motor development was measured using Peabody Developmental Motor Scales-second edition, mental development using Griffiths Development Scales-Chinese (GDS-C). Height standard deviation score (SDS), body weight SDS, and body mass index (BMI) SDS were also assessed.

RESULTS

Thirty-five patients were enrolled totally. Significant improvements were observed in height, body weight, and BMI SDS at week 52; GDS-C score showed significant improvement in general quotient (GQ) and sub-quotients. In a linear regression analysis, total motor quotient (TMQ), gross motor quotient (GMQ), and fine motor quotient were negatively correlated with age; however, treatment may attenuate deterioration of TMQ and GMQ. Changes in GQ and locomotor sub-quotient in < 9-month group were significantly higher than ≥ 9-month group. Mild to moderate severity adverse drug reactions were reported in six patients.

CONCLUSION

Fifty-two-week treatment with rhGH improved growth, BMI, mental development, and lessened the deterioration of motor function in infants and young children with PWS. Improved mental development was more pronounced when instituted in patients < 9 months old.

The Alberta Infant Motor Scale: A tool for the assessment of motor aspects of neurodevelopment in infancy and early childhood

According to the recommendations of the American Academy of Pediatrics, the surveillance of motor development should accompany systematic appointments with medical professionals in infancy and early childhood. One of the standardized tools for evaluating motor development is the Alberta Infant Motor Scale (AIMS). This paper aims to present assumptions and psychometric properties of the AIMS, the methodology of assessment of an infant's performance with the AIMS, and research on the validation and standardization of the AIMS as well as the use of the scale as an outcome measure. We conducted a non-systematic literature review using three electronic databases: PubMed, Scopus, and Embase (from June 1992 to February 2022). We included original research with a full-text manuscript in English. No geographical restrictions were applied. The search terms “alberta infant motor scale” AND “reliability” OR “validity” and “alberta infant motor scale” AND “norms” OR “reference” OR “standardization” were used for literature review on the validation and standardization of the AIMS in other non-Canadian populations. This narrative review also focuses on how the AIMS is applied as an outcome measure in research by presenting studies on the AIMS conducted over the last decade. Our review found that the AIMS is widely used for both research and clinical purposes. The AIMS has been used as an outcome measure in both interventional and observational studies conducted on both neurotypical infants and those with conditions affecting motor development. The advantages of the scale are its infant-friendliness, time duration of the examination, and relative ease of application for an examiner. The scale has been validated and standardized in many countries.

Growth hormone treatment for Prader-Willi syndrome: A review

The Prader-Willi Syndrome (PWS) is a rare developmental disorder that contributed by multiple genes. Phenotypically, infants with PWS exhibit hypotonia and developmental delay, whilst older children and adults have cognitive impairments, neuropsychiatric symptoms, impaired motor development, neurological anomalies, endocrine dysfunctions like growth hormone (GH) deficiency, and hyperphagia that leads to obesity. Although mechanisms remain elusive, GH treatment has been recommended as the standard treatment for PWS children. In addition to better motor development, improved body composition and linear growth have been well established, but mental flexibility and behavioural problems remained largely untouched. This review will systemically analyze the recent clinical trials of GH treatment on PWS patients. The emphasis is on the mental and behavioural improvements by GH treatment, and a few concerns to initiate GH treatment. This review will finally propose possible future explorations on basic studies that may shed new light on clinical trials of GH treatment on PWS.

Growth hormone treatment in Prader-Willi syndrome patients: systematic review and meta-analysis

BACKGROUND

Growth hormone (GH) treatment is currently recommended in Prader-Willi syndrome (PWS) patients.

OBJECTIVES

To evaluate the impact (efficacy and safety) of the use of recombinant human GH (rhGH) as a treatment for PWS.

METHOD

We performed a systematic review and, where possible, meta-analysis for the following outcomes: growth, body mass index, body composition, cognitive function, quality of life, head circumference, motor development/strength, behaviour and adverse effects. We included all PWS patients, with all types of genetic defects and with or without GH deficiency, who participated in rhGH studies performed in infancy, childhood and adolescence, that were either randomised controlled trials (RCTs) (double-blinded or not) or non-randomised controlled trials (NRCTs) (cohort and before and after studies). The databases used were MEDLINE, Embase and Cochrane Central.

RESULTS

In 16 RCTs and 20 NRCTs selected, the treated group had an improvement in height (1.67 SD scores (SDS); 1.54 to 1.81); body mass index z-scores (-0.67 SDS; -0.87 to -0.47) and fat mass proportion (-6.5% SDS; -8.46 to -4.54) compared with the control group. Data about cognition could not be aggregated. Conclusion Based on high quality evidence, rhGH treatment favoured an improvement of stature, body composition and body mass index, modifying the disease's natural history; rhGH treatment may also be implicated in improved cognition and motor development in PWS patients at a young age.

ETHICS AND DISSEMINATION

The current review was approved by the ethical committee of our institution. The results will be disseminated through conference presentations and publications in peer-reviewed journals.

PROSPERO REGISTRATION NUMBER

CRD42019140295.

Effects of recombinant human growth hormone treatment on growth, body composition, and safety in infants or toddlers with Prader-Willi syndrome: a randomized, active-controlled trial

Background

Prader-Willi syndrome (PWS) is a rare complex genetic disorder and is characterized by short stature, muscular hypotonia, abnormal body composition, psychomotor retardation, and hyperphagia. Recombinant human growth hormone (rhGH) treatment improves the symptoms in children with PWS, and early treatment results in more favorable outcomes. However, systematic studies in infants and toddlers under 2 years of age are lacking. This multicenter, randomized, active-controlled, parallel-group, open-label, Phase III study aimed to evaluate the safety of rhGH (Eutropin, LG Chem, Ltd.) and its efficacy on growth, body composition, and motor and cognitive development in infants and toddlers with PWS compared with a comparator treatment (Genotropin, Pfizer, Inc.). Eligible Korean infants or toddlers with PWS were randomly assigned to receive Eutropin or comparator (both 0.24 mg/kg/week, 6 times/week) for 1 year. Height standard deviation score (SDS), body composition, and motor and cognitive development were measured.

Results

Thirty-four subjects (less than 24 months old) were randomized into either the Eutropin (N = 17) group or the comparator (N = 17) group. After 52 weeks of rhGH treatment, height SDS and lean body mass increased significantly from baseline in both groups: the mean height SDS change (SD) was 0.75 (0.59) in the Eutropin group and 0.95 (0.66) in the comparator group, and the mean lean body mass change (SD) was 2377.79 (536.25) g in the Eutropin group and 2607.10 (641.36) g in the comparator group. In addition, percent body fat decreased significantly: the mean (SD) change from baseline was − 8.12% (9.86%) in the Eutropin group and − 7.48% (10.26%) in the comparator group. Motor and cognitive developments were also improved in both groups after the 1-year treatment. The incidence of adverse events was similar between the groups.

Conclusions

rhGH treatment for 52 weeks in infants and toddlers with PWS improved growth, body composition, and motor and cognitive development, and efficacy and safety outcomes of Eutropin were comparable to those of Genotropin. Hence, Eutropin is expected to provide safe and clinically meaningful improvements in pediatric patients with PWS.

Trial registration

The study was registered at ClinicalTrials.gov (identifier: NCT02204163) on July 30, 2014.

URL: https://clinicaltrials.gov/ct2/show/NCT02204163?term=NCT02204163&rank=1

Early motor and pre-linguistic verbal development in Prader-Willi syndrome - A case report

BACKGROUND

Prader-Willi syndrome (PWS) is a rare genetic disorder. Infants with PWS show a neurodevelopmental dysfunction which entails a delayed motor and language development, but studies on their spontaneous movements (i.e. general movements) or pre-linguistic speech-language development before 6 months of age are missing so far.

AIM

To describe early motor and pre-linguistic verbal development in an infant with PWS.

METHODS AND PROCEDURES

Prospective case report; in addition to the assessment of general movements and the concurrent movement repertoire, we report on early verbal forms, applying the Stark Assessment of Early Vocal Development-Revised.

OUTCOMES AND RESULTS

General movements were abnormal on days 8 and 15. No fidgety movements were observed at 11 weeks; they only emerged at 17 weeks and lasted until at least 27 weeks post-term. The movement character was monotonous, and early motor milestones were only achieved with a delay. At 27 weeks the infant produced age-adequate types of vocalisations. However, none of the canonical-syllable vocalisations that typically emerge at that age were observed. Early vocalisations appeared monotonous and with a peculiarly harmonic structure.

CONCLUSIONS AND IMPLICATIONS

Early motor and pre-linguistic verbal behaviours were monotonous in an infant with PWS throughout his first 6 months of life. This suggests that early signs of neurodevelopmental dysfunction (i.e. abnormal general movements) might already be diagnosed in infants with PWS during their first weeks of life, potentially enabling us to diagnose and intervene at an early stage.

Preclinical Testing in Translational Animal Models of Prader-Willi Syndrome: Overview and Gap Analysis

Prader-Willi syndrome (PWS) is a rare neurodevelopmental disorder causing endocrine, musculoskeletal, and neurological dysfunction. PWS is caused by the inactivation of contiguous genes, complicating the development of targeted therapeutics. Clinical trials are now underway in PWS, with more trials to be implemented in the next few years. PWS-like endophenotypes are recapitulated in gene-targeted mice in which the function of one or more PWS genes is disrupted. These animal models can guide priorities for clinical trials or provide information about efficacy of a compound within the context of the specific disease. We now review the current status of preclinical studies that measure the effect of therapeutics on PWS-like endophenotypes. Seven categories of therapeutics (oxytocin and related compounds, K⁺-ATP channel agonists, melanocortin 4 receptor agonists, incretin mimetics and/or GLP-1 receptor agonists, cannabinoids, ghrelin agents, and Caralluma fimbriata [cactus] extract) have been tested for their effect on endophenotypes in both PWS animal models and clinical trials. Many other therapeutics have been tested in clinical trials, but not preclinical models of PWS or vice versa. Fostering dialogs among investigators performing preclinical validation of animal models and those implementing clinical studies will accelerate the discovery and translation of therapies into clinical practice in PWS.

Improved Mental and Motor Development During 3 Years of GH Treatment in Very Young Children With Prader-Willi Syndrome

CONTEXT

Infants and toddlers with Prader-Willi syndrome (PWS) have mental and motor developmental delay. Short-term data suggest a positive effect of GH on mental and motor development in infants and children with PWS. There are, however, no longer-term results about the effects of GH treatment on mental and motor development.

OBJECTIVE

To investigate the longer-term effects of GH on psychomotor development in infants and toddlers with PWS and the effect of age at start of GH treatment on psychomotor development.

DESIGN

Prospective cohort study during 3 years of GH treatment.

SETTING

The PWS Reference Center in the Netherlands.

INTERVENTION

All children were treated with GH 1 mg/m2/d (≈0.035 mg/kg/d).

MAIN OUTCOME MEASURES

Mental and motor developmental age assessed with Bayleys Scales of Infant Development II and expressed as percentage of the expected development (100%).

RESULTS

During 3 years of GH, mean (SEM) mental development increased from 58.1% (2.8) at baseline to 79.6% (3.7), and motor development increased from 41.9% (2.9) to 78.2% (3.9; both P < 0.01). A lower baseline psychomotor development and a younger age at start of GH treatment were associated with a higher increase in mental and motor development (P < 0.01).

CONCLUSIONS

Mental and motor development increased significantly during 3 years of GH treatment, reducing the gap between infants with PWS and healthy peers. A younger age at start of GH treatment leads to greater improvement in psychomotor development.

Shared Decision-Making in Growth Hormone Therapy-Implications for Patient Care

Several studies have shown that adherence to growth hormone therapy (GHT) is not optimal. There are several reasons why patients may not fully adhere to their treatment regimen and this may have implications on treatment success, patient outcomes and healthcare spending and resourcing. A change in healthcare practices, from a physician paternalistic to a more patient autonomous approach to healthcare, has encouraged a greater onus on a shared decision-making (SDM) process whereby patients are actively encouraged to participate in their own healthcare decisions. There is growing evidence to suggest that SDM may facilitate patient adherence to GHT. Improved adherence to therapy in this way may consequently positively impact treatment outcomes for patients. Whilst SDM is widely regarded as a healthcare imperative, there is little guidance on how it should be best implemented. Despite this, there are many opportunities for the implementation of SDM during the treatment journey of a patient with a GH-related disorder. Barriers to the successful practice of SDM within the clinic may include poor patient education surrounding their condition and treatment options, limited healthcare professional time, lack of support from clinics to use SDM, and healthcare resourcing restrictions. Here we discuss the opportunities for the implementation of SDM and the barriers that challenge its effective use within the clinic. We also review some of the potential solutions to overcome these challenges that may prove key to effective patient participation in treatment decisions. Encouraging a sense of empowerment for patients will ultimately enhance treatment adherence and improve clinical outcomes in GHT.

Cognitive and adaptive advantages of growth hormone treatment in children with Prader-Willi syndrome

BACKGROUND

People with Prader-Willi syndrome (PWS) typically have mild to moderate intellectual deficits, compulsivity, hyperphagia, obesity, and growth hormone deficiencies. Growth hormone treatment (GHT) in PWS has well-established salutatory effects on linear growth and body composition, yet cognitive benefits of GHT, seen in other patient groups, have not been well studied in PWS.

METHODS

Study 1 included 96 children and youth with PWS aged 4-21 years who naturalistically varied in their exposures to GHT. Controlling for socioeconomic status, analyses compared cognitive and adaptive behavior test scores across age-matched treatment naïve versus growth hormone treated children. Study II assessed if age of treatment initiation or treatment duration was associated with subsequent cognition or adaptive behavior in 127, 4- to 21-year olds with PWS. Study III longitudinally examined cognitive and adaptive behavior in 168 participants who were either consistently on versus off GHT for up to 4-5 years.

RESULTS

Compared to the treatment naïve group, children receiving GHT had significantly higher Verbal and Composite IQs, and adaptive communication and daily living skills. Children who began treatment before 12 months of age had higher Nonverbal and Composite IQs than children who began treatment between 1 and 5 years of age. Longitudinally, the groups differed in their intercepts, but not slopes, with each group showing stable IQ and adaptive behavior scores over time.

CONCLUSIONS

Cognitive and adaptive advantages should be considered an ancillary benefit and additional justification for GHT in people with PWS. Future efforts need to target apparent socioeconomic inequities in accessing GHT in the PWS population.

Alberta Infant Motor Scale (AIMS) Performance of Greek Preterm Infants: Comparisons With Full-Term Infants of the Same Nationality and Impact of Prematurity-Related Morbidity Factors

BACKGROUND

Only a few studies have been conducted with the objective of creating norms of the Alberta Infant Motor Scale (AIMS) for the assessment of gross motor development of preterm infants. The AIMS performance of preterm infants has been compared with that of the Canadian norms of full-term infants, but not with that of full-term infants of the same nationality. Moreover, the possible impact of prematurity-related morbidity factors on AIMS performance is unknown.

OBJECTIVES

The aims of this study were: (1) to evaluate AIMS trajectory in a large population of Greek preterm infants and create norms, (2) to compare it with the AIMS trajectory of Greek full-term infants, and (3) to examine the possible influence of neonatal morbidity on AIMS scores in the preterm sample.

DESIGN

This was a cross-sectional study.

METHODS

Mean AIMS scores were compared, per month (1-19), between 403 preterm infants (≤32 weeks of age, corrected for prematurity) and 1,038 full-term infants. In preterm infants, the association of AIMS scores with respiratory distress syndrome (RDS), intraventricular hemorrhage (IVH) of grade ≤III, bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), and sepsis was assessed by hierarchical regression analysis.

RESULTS

Alberta Infant Motor Scale scores were significantly lower in preterm infants than in full-term infants. Mean AIMS scores in preterm infants were significantly associated with RDS (b=-1.93; 95% CI=-2.70, -1.16), IVH (b=-0.97; 95% CI=-1.69, -0.25), and ROP (b=-1.12; 95% CI=-1.99, -0.24) but not with BPD or sepsis in hierarchical regression analysis.

CONCLUSIONS

Alberta Infant Motor Scale norms were created for Greek preterm infants. This study confirms that AIMS trajectories of preterm infants are below those of full-term infants of the same nationality. The influence of morbidity factors, including RDS, IVH, and ROP, should be taken into account when administering the AIMS in preterm infants.

Growth hormone therapy for Prader-willi syndrome: challenges and solutions

Prader-Willi syndrome (PWS) is characterized by a dysregulation of growth hormone (GH)/insulin-like growth factor I axis, as the consequence of a complex hypothalamic involvement. PWS' clinical picture seems to resemble the classic non-PWS GH deficiency (GHD), including short stature, excessive body fat, decreased muscle mass, and impaired quality of life. GH therapy is able to ameliorate the phenotypic appearance of the syndrome, as well as to improve body composition, physical strength, and cognitive level. In this regard, however, some pathophysiologic and clinical questions still remain, representing a challenge to give the most appropriate care to PWS patients. Data about the prevalence of GHD in PWS children are not unequivocal, ranging from 40% to 100%. In this context, to establish whether the presence (or not) of GHD may have a different effect on clinical course during GH therapy may be helpful. In addition, the comparison of GH effects in PWS children diagnosed as small for gestational age with those obtained in subjects born appropriate for gestational age is of potential interest for future trials. Emerging information seems to demonstrate the maintenance of beneficial effects of GH therapy in PWS subjects after adolescent years. Thus, GH retesting after achievement of final height should be taken into consideration for all PWS patients. However, it is noteworthy that GH administration exerts positive effects both in PWS adults with and without GHD. Another critical issue is to clarify whether the genotype-phenotype correlations may be relevant to specific outcome measures related to GH therapy. Moreover, progress of our understanding of the role of GH replacement and concomitant therapies on bone characteristics of PWS is required. Finally, a long-term surveillance of benefits and risks of GH therapy is strongly recommended for PWS population, since most of the current studies are uncontrolled and of short duration.

Behavior in children with Prader-Willi syndrome before and during growth hormone treatment: a randomized controlled trial and 8-year longitudinal study

Information on behavior of children with Prader-Willi syndrome (PWS) and the effect of growth hormone (GH) treatment is scarce. Parents report less problem behavior during GH treatment. Forty-two pre-pubertal children, aged 3.5-14 years were studied in a randomized controlled GH trial (RCT) during 2 years, followed by a longitudinal study during 8 years of GH treatment. Behavior was measured annually by the Developmental Behavior Checklist for children with intellectual disability (DBC) and a Dutch questionnaire to evaluate social behavioral problems in children, the Children's Social Behavior Questionnaire (CSBQ). Problem behavior measured by the DBC in children with PWS was similar compared to peers with comparable intellectual disability. Scores on 'Social disabilities' subscale were however significantly higher compared to the DBC total score (p < 0.01). A lower IQ was associated with more self-absorbed behavior, more communication problems and more problem behavior in general. Problem behavior measured by the CSBQ was similar compared to peers with a comparable intellectual disability, but children with PWS scored significantly higher on the 'Not tuned', 'Understanding', and 'Stereotyped' subscales than the CSBQ total score (p < 0.05 for all subscales and p = 0.001 for the 'Not tuned'-subscale). There were no significant effects of GH treatment during the RCT and 8 years of GH treatment. Children with PWS showed similar problem behavior as a reference population with a comparable intellectual disability. Social problems were the most pronounced within-problem behavior in PWS. In contrast to our expectations and parents reports, our study shows no improvement but also no deterioration of behavioral problems in children with PWS during long-term GH treatment.

Visual-motor integration in children with Prader-Willi syndrome

BACKGROUND

Prader-Willi syndrome (PWS) is characterised by hypotonia, hypogonadism, short stature, obesity, behavioural problems, intellectual disability, and delay in language, social and motor development. There is very limited knowledge about visual-motor integration in children with PWS.

METHOD

Seventy-three children with PWS aged 7-17 years were included. Visual-motor integration was assessed using the Beery Visual-motor Integration test at the start of the study and after 2 years. The association between visual-motor integration and age, gender, genetic subtype and intelligence was assessed.

RESULTS

Children with PWS scored 'very low' (-3 standard deviations) in visual-motor integration and 'below average' (-1 standard deviation) in visual perception and motor coordination compared with typically developing children. Visual-motor integration was higher in children with a deletion (β = -0.170, P = 0.037), in older children (β = 0.222, P = 0.009) and in those with a higher total IQ (β = 0.784, P < 0.001). Visual perception was higher with a deletion (β = -0.193, P = 0.044) and higher IQ (β = -0.618, P < 0.001), but motor coordination was only higher with a higher total IQ (β = 0.429, P = 0.001). Visual perception and motor coordination were not associated with age or gender. There was a trend for visual-motor integration decline over the 2 year follow-up period (P = 0.099). Visual perception and motor coordination did not change over the follow-up period.

CONCLUSIONS

Visual-motor integration is very poor in children with PWS. Children scored higher on the time-limited subtests for visual perception and motor coordination than the combined test for visual-motor integration. Separation of visual-motor integration tasks into pure visual or motor tasks and allowing sufficient time to perform the tasks might improve daily activities, both at home and at school.

Growth hormone therapy, muscle thickness, and motor development in Prader-Willi syndrome: an RCT

OBJECTIVE

To investigate the effect of physical training combined with growth hormone (GH) on muscle thickness and its relationship with muscle strength and motor development in infants with Prader-Willi syndrome (PWS).

METHODS

In a randomized controlled trial, 22 infants with PWS (12.9 ± 7.1 months) were followed over 2 years to compare a treatment group (n = 10) with a waiting-list control group (n = 12). Muscle thickness of 4 muscle groups was measured by using ultrasound. Muscle strength was evaluated by using the Infant Muscle Strength meter. Motor performance was measured with the Gross Motor Function Measurement. Analyses of variance were used to evaluate between-group effects of GH on muscle thickness at 6 months and to compare pre- and posttreatment (after 12 months of GH) values. Multilevel analyses were used to evaluate effects of GH on muscle thickness over time, and multilevel bivariate analyses were used to test relationships between muscle thickness, muscle strength, and motor performance.

RESULTS

A significant positive effect of GH on muscle thickness (P < .05) was found. Positive relationships were found between muscle thickness and muscle strength (r = 0.61, P < .001), muscle thickness and motor performance (r = 0.81, P < .001), and muscle strength and motor performance (r = 0.76, P < .001).

CONCLUSIONS

GH increased muscle thickness, which was related to muscle strength and motor development in infants with PWS. Catch-up growth was faster in muscles that are most frequently used in early development. Because this effect was independent of GH, it suggests a training effect.

Prader-Willi syndrome: a single center's experience in Korea

PURPOSE

Prader-Willi syndrome (PWS) is a complex genetic disorder that results from the lack of paternally expressed genes in the chromosome 15q11-q13 region. This study was performed to delineate the clinical features of PWS infants and toddlers and the effects of two-year growth hormone (GH) treatment according to gender and age at the start of treatment.

METHODS

The clinical characteristics and the results of the GH treatment were reviewed retrospectively for 30 PWS patients diagnosed by molecular genetic testing and clinical manifestations.

RESULTS

The mean age at diagnosis with PWS was 13.7 months (2-47 months of age). All patients showed the characteristics of facial dysmorphism, including brown hair and almond-shaped eyes. Most patients showed developmental delays/mental retardation (93.3%), cryptorchidism (75%), feeding problems in infancy (73.3%), and neonatal or infantile hypotonia (66.7%). Among 30 patients, 14 PWS infants and toddlers had been treated with GH for more than two years. Two years of GH treatment resulted in an improvement in head circumference-standard deviation score (HC-SDS), body weight-SDS, insulin-like growth factor-1 (IGF-1) SDS, IGF binding protein-3 (IGFBP-3) SDS, lean body mass, and bone mineral content, especially in IGFBP-3 SDS and motor development in PWS patients younger than two years of age. There was significant increase in IGF-1 SDS and IGFBP-3 SDS among male PWS patients after GH treatment.

CONCLUSION

Our study showed increases in IGFBP-3 SDS and an improvement in motor development among individuals under two years of age after GH treatment, and significant difference in IGF-1 SDS and IGFBP-3 SDS by gender.