Growth charts for non-growth hormone treated Prader-Willi syndrome

Growth Charts for Children With Arthrogryposis Multiplex Congenita

Children with arthrogryposis multiplex congenita (AMC) often demonstrate growth differences compared with typically developing (TD) children. However, growth charts have not been developed for this population. The purpose of this study was to create AMC-specific growth charts and to compare these values to those of TD children. A retrospective review of height/length and weight for 206 children with AMC was performed. Growth charts were developed and stratified over seven percentiles; these were then compared with growth charts of TD children. Children with AMC tend to be smaller in stature and weight compared with TD children, particularly in the first 36 months of life. Thereafter, weight values trend toward the 50th percentile of TD children, but height/length values persist around the 5th percentile of TD children. The development of AMC-specific growth charts provides health care providers an objective tool to evaluate growth patterns of patients with AMC.

Development of disease-specific growth charts for Korean children with Beckwith-Wiedemann syndrome

Beckwith-Wiedemann syndrome (BWS) is an epigenetic overgrowth syndrome. Despite its distinctive growth pattern, the detailed growth trajectories of children with BWS remain largely unknown. We retrospectively analyzed 413 anthropometric measurements over an average of 4.4 years of follow-up in 51 children with BWS. We constructed sex-specific percentile curves for height, weight, and head circumference using a generalized additive model for location, scale, and shape. Males with BWS exhibited greater height at all ages evaluated, weight before the age of 10, and head circumference before the age of 9 than those of the general population. Females with BWS showed greater height before the age of 7, weight before the age of 4.5, and head circumference before the age of 7 than those of the general population. At the latest follow-up visit at a mean 8.4 years of age, bone age was significantly higher than chronological age. Compared to paternal uniparental disomy (pUPD), males with imprinting center region 2-loss of methylation (IC2-LOM) had higher standard deviation score (SDS) for height and weight, while females with IC2-LOM showed larger SDS for head circumference. These disease-specific growth charts can serve as valuable tools for clinical monitoring of children with BWS.

Standardized growth charts for children with osteogenesis imperfecta

BACKGROUND

Osteogenesis imperfecta (OI) is associated with short stature, which is mild, severe and moderate in OI types I, III and IV, respectively. Standardized OI type- and sex-specific growth charts across all pediatric ages do not exist.

METHODS

We assessed 573 individuals with OI (type I, III or IV), each with at least one height measurement between ages 3 months and 20 years (total 6523 observations). Analogous to the Centers for Disease Control pediatric growth charts, we generated OI type- and sex-specific growth charts for infants (ages 3-36 months) as well as children and adolescents (ages 2-20 years). Growth curves were fitted to the data using the LMS method and percentiles were smoothed.

RESULTS

Age was associated with a decline in height z-scores (p < 0.001 for all OI types), which was more pronounced in females. Height multiplier curves were produced to predict adult height in children with OI. Among individuals with OI type I, those with COL1A1 pathogenic variants leading to haploinsufficiency were taller than those with COL1A1 or COL1A2 pathogenic variants not leading to haploinsufficiency.

CONCLUSION

Our standardized OI type- and sex-specific growth charts can be used to assess the growth of individuals with OI from infancy to adulthood.

IMPACT

Standardized osteogenesis imperfecta (OI) type- and sex-specific growth charts across all pediatric ages do not exist. Our study is the first to generate OI type- and sex-specific growth charts across all pediatric ages. Our height multiplier curves can be utilized to predict adult height in children with OI.

The past, present, and future of child growth monitoring: A review and primer for clinical genetics

Child growth measurements are critical vital signs to track, with every individual child growth curve potentially revealing a story about a child's health and well-being. Simply put, every baby born requires basic building blocks to grow and thrive: proper nutrition, love and care, and medical health. To ensure that every child who is missing one of these vital aspects is identified, growth is traditionally measured at birth and each well-child visit. While the blue and pink growth curves appear omnipresent in pediatric clinics, it is surprising to realize that their use only became standard of care in 1977 when the National Center for Health Statistics (NCHS) adopted the growth curve as a clinical tool for health. Behind this practice lies a socioeconomically, culturally, and politically complex interplay of individuals and institutions around the world. In this review, we highlight the often forgotten past, current state of practice, and future potential of this powerful clinical tool: the growth reference chart, with a particular focus on clinical genetics practice. The goal of this article is to understand ongoing work in the field of anthropometry (the scientific study of human measurements) and its direct impact on modern pediatric and genetic patient care.

Premature adrenarche in Prader-Willi syndrome is associated with accelerated pre-pubertal growth and advanced bone age

OBJECTIVES

Prader-Willi syndrome (PWS) is characterized by obesity, growth hormone deficiency, hypogonadism, and a high prevalence of premature adrenarche despite reported hypothalamic-pituitary-adrenal axis dysfunction. While idiopathic premature adrenarche is associated with accelerated pre-pubertal growth and advanced bone age, the consequences of elevated adrenal androgens on growth and bone maturation in PWS remain unknown. This study therefore sought to describe age-related changes in dehydroepiandrosterone sulfate (DHEAS) and their effects on growth and bone maturation in PWS.

METHODS

This retrospective observational study included 62 children with PWS. Simple and multiple regression models were constructed to relate age and BMI-SDS with DHEAS levels. Height velocity was compared to age and sex-based norms with t-tests and two-way ANOVA. Patterns in bone age Z-score were examined with two-way ANOVA, and the contributions of age, BMI-SDS, and DHEAS to bone age Z-score were analyzed with multiple regression.

RESULTS

DHEAS levels rose earlier and were less strongly correlated with age in males and females with PWS (R²=0.12 and 0.30) compared to healthy controls (R²=0.89 and 0.88) in a pattern unrelated to BMI-SDS (adjusted R²=0.076, p=0.10 for age, and 0.29 for BMI-SDS). Mid-childhood height velocity was increased in males and preserved in females with PWS before declining at the age of expected puberty (p<0.0001). Peri-adrenarchal bone age was advanced in a manner associated with DHEAS but not BMI-SDS (p<0.0001; adjusted R²=0.48, p=0.0014 for DHEAS, and 0.78 for BMI-SDS).

CONCLUSIONS

An obesity-independent increase in adrenal androgens is associated with accelerated mid-childhood growth and bone maturation in PWS.

Genetic conditions of short stature: A review of three classic examples

Noonan, Turner, and Prader-Willi syndromes are classical genetic disorders that are marked by short stature. Each disorder has been recognized for several decades and is backed by extensive published literature describing its features, genetic origins, and optimal treatment strategies. These disorders are accompanied by a multitude of comorbidities, including cardiovascular issues, endocrinopathies, and infertility. Diagnostic delays, syndrome-associated comorbidities, and inefficient communication among the members of a patient's health care team can affect a patient's well-being from birth through adulthood. Insufficient information is available to help patients and their multidisciplinary team of providers transition from pediatric to adult health care systems. The aim of this review is to summarize the clinical features and genetics associated with each syndrome, describe best practices for diagnosis and treatment, and emphasize the importance of multidisciplinary teams and appropriate care plans for the pediatric to adult health care transition.

BDV Syndrome: An Emerging Syndrome With Profound Obesity and Neurodevelopmental Delay Resembling Prader-Willi Syndrome

CONTEXT

CPE encodes carboxypeptidase E, an enzyme that converts proneuropeptides and propeptide hormones to bioactive forms. It is widely expressed in the endocrine and central nervous system. To date, 4 individuals from 2 families with core clinical features including morbid obesity, neurodevelopmental delay, and hypogonadotropic hypogonadism, harboring biallelic loss-of-function (LoF) CPE variants, have been reported.

OBJECTIVE

We describe 4 affected individuals from 3 unrelated consanguineous families, 2 siblings of Syrian, 1 of Egyptian, and 1 of Pakistani descent, all harboring novel homozygous CPE LoF variants.

METHODS

After excluding Prader-Willi syndrome (PWS), exome sequencing was performed in both Syrian siblings. The variants identified in the other 2 individuals were reported as research variants in a large-scale exome study and in the ClinVar database. Computational modeling of all possible missense alterations allowed assessing CPE tolerance to missense variants.

RESULTS

All affected individuals were severely obese with neurodevelopmental delay and other endocrine anomalies. Three individuals from 2 families shared the same CPE homozygous truncating variant c.361C > T, p.(Arg121*), while the fourth carried the c.994del, p.(Ser333Alafs*22) variant. Comparison of clinical features with previously described cases and standardization according to the Human Phenotype Ontology terms indicated a recognizable clinical phenotype, which we termed Blakemore-Durmaz-Vasileiou (BDV) syndrome. Computational analysis indicated high conservation of CPE domains and intolerance to missense changes.

CONCLUSION

Biallelic truncating CPE variants are associated with BDV syndrome, a clinically recognizable monogenic recessive syndrome with childhood-onset obesity, neurodevelopmental delay, hypogonadotropic hypogonadism, and hypothyroidism. BDV syndrome resembles PWS. Our findings suggest missense variants may also be clinically relevant.

Prader-Willi syndrome: reflections on seminal studies and future therapies

Prader-Willi syndrome (PWS) is caused by the loss of function of the paternally inherited 15q11-q13 locus. This region is governed by genomic imprinting, a phenomenon in which genes are expressed exclusively from one parental allele. The genomic imprinting of the 15q11-q13 locus is established in the germline and is largely controlled by a bipartite imprinting centre. One part, termed the Prader-Willi syndrome imprinting center (PWS-IC), comprises a CpG island that is unmethylated on the paternal allele and methylated on the maternal allele. The second part, termed the Angelman syndrome imprinting centre, is required to silence the PWS_IC in the maternal germline. The loss of the paternal contribution of the imprinted 15q11-q13 locus most frequently occurs owing to a large deletion of the entire imprinted region but can also occur through maternal uniparental disomy or an imprinting defect. While PWS is considered a contiguous gene syndrome based on large-deletion and uniparental disomy patients, the lack of expression of only non-coding RNA transcripts from the SNURF-SNRPN/SNHG14 may be the primary cause of PWS. Patients with small atypical deletions of the paternal SNORD116 cluster alone appear to have most of the PWS related clinical phenotypes. The loss of the maternal contribution of the 15q11-q13 locus causes a separate and distinct condition called Angelman syndrome. Importantly, while much has been learned about the regulation and expression of genes and transcripts deriving from the 15q11-q13 locus, there remains much to be learned about how these genes and transcripts contribute at the molecular level to the clinical traits and developmental aspects of PWS that have been observed.

Congenital ichthyosis in Prader-Willi syndrome associated with maternal chromosome 15 uniparental disomy: Case report and review of autosomal recessive conditions unmasked by UPD

Prader-Willi syndrome (PWS) is a prototypic genetic condition related to imprinting. Causative mechanisms include paternal 15q11-q13 deletion, maternal chromosome 15 uniparental disomy (UPD15), Prader-Willi Syndrome/Angelman Syndrome (PWS/AS) critical region imprinting defects, and complex chromosomal rearrangements. Maternal UPD15-related PWS poses risks of concomitant autosomal recessive (AR) disorders when the mother carries a pathogenic variant in one of the genes on chromosome 15 associated with autosomal recessive inherited disease. Co-occurrence of autosomal recessive conditions in the setting of UPD leads to increased complexity of the clinical phenotype, and may delay the diagnosis of PWS. We report a patient with PWS and associated congenital ichthyosis due to maternal UPD15, and a homozygous novel pathogenic variant in ceramide synthase 3 (CERS3). We also review the literature of associated disorders reported in the setting of maternal UPD15-related PWS and provide a summary of the previously described CERS3 variants. This represents the second case of autosomal recessive congenital ichthyosis (ARCI) in the setting of PWS and UPD15. There needs to be a high index of suspicion of this genetic mechanism when there is unexpected phenotype or evolution of the clinical course in a patient with PWS.

Growth Trajectories in Genetic Subtypes of Prader-Willi Syndrome

Prader–Willi syndrome (PWS) is a rare disorder caused by the loss of expression of genes on the paternal copy of chromosome 15q11-13. The main molecular subtypes of PWS are the deletion of 15q11-13 and non-deletion, and differences in neurobehavioral phenotype are recognized between the subtypes. This study aimed to investigate growth trajectories in PWS and associations between PWS subtype (deletion vs. non-deletion) and height, weight and body mass index (BMI). Growth data were available for 125 individuals with PWS (63 males, 62 females), of which 72 (57.6%) had the deletion subtype. There was a median of 28 observations per individual (range 2–85), producing 3565 data points distributed from birth to 18 years of age. Linear mixed models with cubic splines, subject-specific random effects and an autoregressive correlation structure were used to model the longitudinal growth data whilst accounting for the nature of repeated measures. Height was similar for males in both PWS subtypes, with non-deletion females being shorter than deletion females for older ages. Weight and BMI were estimated to be higher in the deletion subtype compared to the non-deletion subtype, with the size of difference increasing with advancing age for weight. These results suggest that individuals with deletion PWS are more prone to obesity.

Mowat-Wilson syndrome: growth charts

BACKGROUND

Mowat-Wilson syndrome (MWS; OMIM #235730) is a genetic condition caused by heterozygous mutations or deletions of the ZEB2 gene. It is characterized by moderate-severe intellectual disability, epilepsy, Hirschsprung disease and multiple organ malformations of which congenital heart defects and urogenital anomalies are the most frequent ones. To date, a clear description of the physical development of MWS patients does not exist. The aim of this study is to provide up-to-date growth charts specific for infants and children with MWS. Charts for males and females aged from 0 to 16 years were generated using a total of 2865 measurements from 99 MWS patients of different ancestries. All data were collected through extensive collaborations with the Italian MWS association (AIMW) and the MWS Foundation. The GAMLSS package for the R statistical computing software was used to model the growth charts. Height, weight, body mass index (BMI) and head circumference were compared to those from standard international growth charts for healthy children.

RESULTS

In newborns, weight and length were distributed as in the general population, while head circumference was slightly smaller, with an average below the 30th centile. Up to the age of 7 years, weight and height distribution was shifted to slightly lower values than in the general population; after that, the difference increased further, with 50% of the affected children below the 5th centile of the general population. BMI distribution was similar to that of non-affected children until the age of 7 years, at which point values in MWS children increased with a less steep slope, particularly in males. Microcephaly was sometimes present at birth, but in most cases it developed gradually during infancy; many children had a small head circumference, between the 3rd and the 10th centile, rather than being truly microcephalic (at least 2 SD below the mean). Most patients were of slender build.

CONCLUSIONS

These charts contribute to the understanding of the natural history of MWS and should assist pediatricians and other caregivers in providing optimal care to MWS individuals who show problems related to physical growth. This is the first study on growth in patients with MWS.

New Features for Child Metrics: Further Growth References and Blood Pressure Calculations

Many new features have recently been incorporated to ÇEDD Çözüm/Child Metrics, an online and freely accessible scientific toolset. Various auxological assessments can now be made with data of children with genetic diseases (Prader Willi syndrome, Noonan syndrome, Turner syndrome, Down syndrome, and Achondroplasia) and preterm and term newborns. More detailed reports for height, weight, and body mass index data of a given child are now available. Last but not least, office and 24-hour ambulatory blood pressure values can be analyzed according to normative data.

Growth charts for Thai children with Prader-Willi syndrome aged 0-18 years

BACKGROUND

Prader-Willi syndrome (PWS) is a multisystem genetic disorder, which has a typical eating behavior and growth pattern. In the infancy period, children with PWS have low body weight followed by hyperphagia in later childhood. Disease-specific growth charts have been recommended for monitoring PWS patients. Previous literature demonstrated growth differences among individuals with PWS of different ethnicity.

METHODS

A retrospective multicenter study was performed in PWS patients from different areas of Thailand included collaboration with the Thai PWS support group during 2000-2017. Baseline characteristics and anthropometric data were reviewed. Both growth hormone and non-growth hormone received patients were included, but the data after receiving GH were excluded before curve construction. Growth charts for Thai PWS compared to the 50th normative centile were constructed using Generalized Least Squares (GLS) methods. Curve smoothing was performed by Fractional Polynomials and Exponential Transformation.

RESULT

One hundred and thirteen patients with genetically confirmed PWS (55 males and 58 females) were enrolled. Fifty percent of patients were diagnosed less than 6 months of age. We developed growth charts for non-growth hormone treated Thai children with PWS aged between 0 and 18 years. A growth pattern was similar to other ethnicities while there were some differences. Mean birth weight of PWS patients was less than that of typical newborns. Mean adult height at 18 years of age in Thai children with PWS was lower than that in American children, but taller than Japanese. Mean weight of Thai PWS males at 18 years of age was more than those from other countries.

CONCLUSION

This study is the first to document PWS-specific growth charts in Southeast Asian population. These growth charts will be useful in improving the quality of patient care and in evaluating the impact of growth hormone treatment in the future.

Early Diagnosis in Prader-Willi Syndrome Reduces Obesity and Associated Co-Morbidities

Prader–Willi syndrome (PWS) is an imprinting genetic disorder characterized by lack of expression of genes on the paternal chromosome 15q11–q13 region. Growth hormone (GH) replacement positively influences stature and body composition in PWS. Our hypothesis was that early diagnosis delays onset of obesity in PWS. We studied 352 subjects with PWS, recruited from the NIH Rare Disease Clinical Research Network, to determine if age at diagnosis, ethnicity, gender, and PWS molecular class influenced the age they first become heavy, as determined by their primary care providers, and the age they first developed an increased appetite and began seeking food. The median ages that children with PWS became heavy were 10 years, 6 years and 4 years for age at diagnosis < 1 year, between 1 and 3 years, and greater than 3 years of age, respectively. The age of diagnosis and ethnicity were significant factors influencing when PWS children first became heavy (p < 0.01), however gender and the PWS molecular class had no influence. Early diagnosis delayed the onset of becoming heavy in individuals with PWS, permitting early GH and other treatment, thus reducing the risk of obesity-associated co-morbidities. Non-white individuals had an earlier onset of becoming heavy.

Requirements for improving health and well-being of children with Prader-Willi syndrome and their families

Prader-Willi syndrome (PWS) is a rare genetic condition with multi-system involvement. The literature was reviewed to describe neurodevelopment and the behavioural phenotype, endocrine and metabolic disorders and respiratory and sleep functioning. Implications for child and family quality of life were explored. Challenging behaviours contribute to poorer well-being and quality of life for both the child and caregiver. Recent evidence indicates healthy outcomes of weight and height can be achieved with growth hormone therapy and dietary restriction and should be the current target for all individuals with PWS. Gaps in the literature included therapies to manage challenging behaviours, as well as understanding the effects of growth hormone on respiratory and sleep function. New knowledge regarding the transition of children and families from schooling and paediatric health services to employment, accommodation and adult health services is also needed. Developing a national population-based registry could address these knowledge gaps and inform advocacy for support services that improve the well-being of individuals with PWS and their families.

Anthropometric characteristics of newborns with Prader-Willi syndrome

This is a retrospective multicenter nationwide Italian study collecting neonatal anthropometric data of Caucasian subjects with Prader-Willi syndrome (PWS) born from 1988 to 2018. The aim of the study is to provide percentile charts for weight and length of singletons with PWS born between 36 and 42 gestational weeks. We collected the birth weight and birth length of 252 male and 244 female singleton live born infants with both parents of Italian origin and PWS genetically confirmed. Percentile smoothed curves of birth weight and length for gestational age were built through Cole's lambda, mu, sigma method. The data were compared to normal Italian standards. Newborns with PWS showed a lower mean birth weight, by 1/2 kg, and a shorter mean birth length, by 1 cm, than healthy neonates. Females with a 15q11-13 deletion were shorter than those with maternal uniparental maternal disomy of chromosome 15 (p < .0001). The present growth curves may be useful as further traits in supporting a suspicion of PWS in a newborn. Because impaired prenatal growth increases risk of health problems later in life, having neonatal anthropometric standards could be helpful to evaluate possible correlations between the presence or absence of small gestational age and some clinical and metabolic aspects of PWS.

Development of disorder-specific normative data for growth in children with cerebral palsy

The purpose of this study was to create growth-percentiles for Caucasian children with cerebral palsy (CP). The studied parameters were height and age. In a retrospective analysis, we converted measurements collected in our center to create disorder-specific percentiles of normative data. Patients were stratified due to sex (male and female) and to mobility levels using the gross motor function classification system (GMFCS) (A = walking; GMFCS I-III, B = non walking; GMFCS IV-V) into four groups. In total, 2363 measurements in patients 0-18 years were collected. The mean age for group "Am" was 6.8 years (n = 862), group "Bm" 7.6 years (n = 563), group "Af" 7.7 years (n = 600), and group "Bf" 8.2 years (n = 366). The created percentiles for all groups were below the reference percentiles for healthy Caucasian children (KiGGS). The median curve for children with GMFCS levels I-III is slightly above the 3rd percentile, whereas the 50th percentile for GMFCS levels IV-V is mostly below the 3rd KiGGS centile.Conclusion: In conclusion, children with cerebral palsy are smaller than healthy children. The difference between 50th percentile of CP patients compared to healthy children supports the need for the use of disorder-specific growth charts. Those charts can help clinicians differentiate growth disorders in patients with CP. What is Known: • Children with cerebral palsy are shorter than healthy children and height is influenced by level of ambulation. • Currently, only reference percentiles of American children with mixed ethical backgrounds are available to evaluate growth. What is New: • This paper presents disorder-specific reference percentiles for longitudinal growth of Caucasian children with cerebral palsy depending on motor function. • These percentiles allow to asses longitudinal growth in children with cerebral palsy to detect other additional diseases impairing growth.

Prader-Willi Syndrome - Clinical Genetics, Diagnosis and Treatment Approaches: An Update

BACKGROUND

Prader-Willi Syndrome (PWS) is a neurodevelopmental genomic imprinting disorder with lack of expression of genes inherited from the paternal chromosome 15q11-q13 region usually from paternal 15q11-q13 deletions (about 60%) or maternal uniparental disomy 15 or both 15s from the mother (about 35%). An imprinting center controls the expression of imprinted genes in the chromosome 15q11-q13 region. Key findings include infantile hypotonia, a poor suck, failure to thrive and hypogonadism/hypogenitalism. Short stature and small hands/feet due to growth and other hormone deficiencies, hyperphagia and marked obesity occur in early childhood, if uncontrolled. Cognitive and behavioral problems (tantrums, compulsions, compulsive skin picking) are common.

OBJECTIVE

Hyperphagia and obesity with related complications are major causes of morbidity and mortality in PWS. This report will describe an accurate diagnosis with determination of specific genetic subtypes, appropriate medical management and best practice treatment approaches.

METHODS AND RESULTS

An extensive literature review was undertaken related to genetics, clinical findings and laboratory testing, clinical and behavioral assessments and summary of updated health-related information addressing the importance of early PWS diagnosis and treatment. A searchable, bulleted and formatted list of topics is provided utilizing a Table of Contents approach for the clinical practitioner.

CONCLUSION

Physicians and other health care providers can use this review with clinical, genetic and treatment summaries divided into sections pertinent in the context of clinical practice. Frequently asked questions by clinicians, families and other interested participants or providers will be addressed.

Schaaf-Yang syndrome overview: Report of 78 individuals

Schaaf-Yang Syndrome (SYS) is a genetic disorder caused by truncating pathogenic variants in the paternal allele of the maternally imprinted, paternally expressed gene MAGEL2, located in the Prader-Willi critical region 15q11-15q13. SYS is a neurodevelopmental disorder that has clinical overlap with Prader-Willi Syndrome in the initial stages of life but becomes increasingly distinct throughout childhood and adolescence. Here, we describe the phenotype of an international cohort of 78 patients with nonsense or frameshift mutations in MAGEL2. This cohort includes 43 individuals that have been reported previously, as well as 35 newly identified individuals with confirmed pathogenic genetic variants. We emphasize that intellectual disability/developmental delay, autism spectrum disorder, neonatal hypotonia, infantile feeding problems, and distal joint contractures are the most consistently shared features of patients with SYS. Our results also indicate that there is a marked prevalence of infantile respiratory distress, gastroesophageal reflux, chronic constipation, skeletal abnormalities, sleep apnea, and temperature instability. While there are many shared features, patients with SYS are characterized by a wide phenotypic spectrum, including a variable degree of intellectual disability, language development, and motor milestones. Our results indicate that the variation in phenotypic severity may depend on the specific location of the truncating mutation, suggestive of a genotype-phenotype association. This evidence may be useful in both prenatal and pediatric genetic counseling.

Prader-Willi syndrome and early-onset morbid obesity NIH rare disease consortium: A review of natural history study

We describe the National Institutes of Health rare disease consortium for Prader-Willi syndrome (PWS) developed to address concerns regarding medical care, diagnosis, growth and development, awareness, and natural history. PWS results from errors in genomic imprinting leading to loss of paternally expressed genes due to 15q11-q13 deletion, maternal disomy 15 or imprinting defects. The 8 year study was conducted at four national sites on individuals with genetically confirmed PWS and early-onset morbid obesity (EMO) with data accumulated to gain a better understanding of the natural history, cause and treatment of PWS. Enrollment of 355 subjects with PWS and 36 subjects with EMO began in September 2006 with study completion in July 2014. Clinical, genetic, cognitive, behavior, and natural history data were systematically collected along with PWS genetic subtypes, pregnancy and birth history, mortality, obesity, and cognitive status with study details as important endpoints in both subject groups. Of the 355 individuals with PWS, 217 (61%) had the 15q11-q13 deletion, 127 (36%) had maternal disomy 15, and 11 (3%) had imprinting defects. Six deaths were reported in our PWS cohort with 598 cumulative years of study exposure and one death in the EMO group with 42 years of exposure. To our knowledge, this description of a longitudinal study in PWS represents the largest and most comprehensive cohort useful for investigators in planning comparable studies in other rare disorders. Ongoing studies utilizing this database should have a direct impact on care and services, diagnosis, treatment, genotype-phenotype correlations, and clinical outcomes in PWS.

Review of Prader-Willi syndrome: the endocrine approach

Prader-Willi syndrome (PWS) is a complex genetic disorder with implications on the endocrine and neurologic systems, metabolism, and behavior. Early in life, PWS is characterized by hypotonia and failure to thrive, followed by obesity and hyperphagia. Patients with PWS develop hypothalamic dysfunction which may lead growth hormone deficiency (GHD), hypogonadism, hypothyroidism, adrenal insufficiency, and poor bone mineral density (BMD). In addition to hypothalamic dysfunction, individuals with PWS have increased risk for obesity which may be complicated by metabolic syndrome and type 2 diabetes mellitus (T2DM). In this paper, we will review the current literature pertaining to the endocrine concerns of PWS and current recommendations for screening and management of these conditions.

Obesity in adults with 22q11.2 deletion syndrome

PURPOSE

To characterize the prevalence of and contributing factors to adult obesity in the most common recurrent copy-number variation (CNV), 22q11.2 deletion, given that other rare CNVs are known to have obesity phenotypes.

METHODS

In 207 adults with 22q11.2 deletion syndrome (22q11.2DS), we used available height and weight measurements to calculate body mass index (BMI) and recorded associated factors that could play a role in obesity. We used the maximum BMI per subject and logistic regression to test a model predicting obesity class.

RESULTS

The prevalence of obesity (BMI ≥30) in 22q11.2DS (n = 90, 43.5%; at median age of 26.7 years) was significantly greater than for Canadian norms (odds ratio (OR) 2.30, 95% confidence interval (CI) = 1.74-3.02, P < 0.0001), even after excluding individuals with a history of antipsychotic use. The regression model was significant (P < 0.0001). Psychotropic medication use and age, but not sex or presence of intellectual disability, were associated with higher obesity level. Ten (4.8%) individuals were diagnosed with type 2 diabetes at a median age of 39.5 years; the prevalence was higher in those with obesity (P < 0.01).

CONCLUSION

The results suggest that adult obesity is related to the 22q11.2 deletion. The findings expand the potential genetic causes of obesity and have important implications for management of 22q11.2DS.Genet Med 19 2, 204-208.

Diagnosis and treatment of GH deficiency in Prader-Willi syndrome

Prader-Willi syndrome (PWS) results from under-expression of the paternally-derived chromosomal region 15q11-13. Growth failure is a recognized feature of PWS, and both quantitative and qualitative defects of the GH/IGF-I axis revealing GH deficiency (GHD) have been demonstrated in most children with PWS. In PWS adults, criteria for GHD are biochemically fulfilled in 8-38% of the studied cohorts. Published data support benefits of early institution of GH therapy (GHT) in PWS children, with positive effects on statural growth, body composition, metabolic homeostasis, and neurocognitive function. Like in pediatric PWS, GHT also yields beneficial effects on lean and body fat, exercise capacity, and quality of life of PWS adults. Although GHT has been generally administered safely in PWS children and adults, careful surveillance of risks is mandatory during prolonged GH replacement for all PWS individuals.

A boy with Prader-Willi syndrome: unmasking precocious puberty during growth hormone replacement therapy

Prader-Willi syndrome (PWS) is a genetic disorder frequently characterized by obesity, growth hormone deficiency, genital abnormalities, and hypogonadotropic hypogonadism. Incomplete or delayed pubertal development as well as premature adrenarche are usually found in PWS, whereas central precocious puberty (CPP) is very rare. This study aimed to report the clinical and biochemical follow-up of a PWS boy with CPP and to discuss the management of pubertal growth. By the age of 6, he had obesity, short stature, and many clinical criteria of PWS diagnosis, which was confirmed by DNA methylation test. Therapy with recombinant human growth hormone (rhGH) replacement (0.15 IU/kg/day) was started. Later, he presented psychomotor agitation, aggressive behavior, and increased testicular volume. Laboratory analyses were consistent with the diagnosis of CPP (gonadorelin-stimulated LH peak 15.8 IU/L, testosterone 54.7 ng/dL). The patient was then treated with gonadotropin-releasing hormone analog (GnRHa). Hypothalamic dysfunctions have been implicated in hormonal disturbances related to pubertal development, but no morphologic abnormalities were detected in the present case. Additional methylation analysis (MS-MLPA) of the chromosome 15q11 locus confirmed PWS diagnosis. We presented the fifth case of CPP in a genetically-confirmed PWS male. Combined therapy with GnRHa and rhGH may be beneficial in this rare condition of precocious pubertal development in PWS.

Growth Charts for Prader-Willi Syndrome During Growth Hormone Treatment

The purpose of the current study was to develop syndrome-specific standardized growth curves for growth hormone-treated Prader-Willi syndrome (PWS) individuals aged 0 to 18 years. Anthropometric growth-related measures were obtained on 171 subjects with PWS who were treated with growth hormone for at least 40% of their lifespan. They had no history of scoliosis. PWS standardized growth curves were developed for 7 percentile ranges using the LMS method for weight, height, head circumference, weight/length, and BMI along with normative 3rd, 50th, and 97th percentiles plotted using control data from the literature and growth databases. Percentiles were plotted on growth charts for comparison purposes. Growth hormone treatment appears to normalize stature and markedly improves weight in PWS compared with standardized curves for non-growth hormone-treated PWS individuals. Growth chart implications and recommended usage are discussed.

Progress in pediatrics in 2015: choices in allergy, endocrinology, gastroenterology, genetics, haematology, infectious diseases, neonatology, nephrology, neurology, nutrition, oncology and pulmonology

This review focuses key advances in different pediatric fields that were published in Italian Journal of Pediatrics and in international journals in 2015. Weaning studies continue to show promise for preventing food allergy. New diagnostic tools are available for identifying the allergic origin of allergic-like symptoms. Advances have been reported in obesity, short stature and autoimmune endocrine disorders. New molecules are offered to reduce weight gain and insulin-resistance in obese children. Regional investigations may provide suggestions for preventing short stature. Epidemiological studies have evidenced the high incidence of Graves' disease and Hashimoto's thyroiditis in patients with Down syndrome. Documentation of novel risk factors for celiac disease are of use to develop strategies for prevention in the population at-risk. Diagnostic criteria for non-celiac gluten sensitivity have been reported. Negative effect on nervous system development of the supernumerary X chromosome in Klinefelter syndrome has emerged. Improvements have been made in understanding rare diseases such as Rubinstein-Taybi syndrome. Eltrombopag is an effective therapy for immune trombocytopenia. Children with sickle-cell anemia are at risk for nocturnal enuresis. Invasive diseases caused by Streptococcus pyogenes are still common despite of vaccination. No difference in frequency of antibiotic prescriptions for acute otitis media between before the publication of the national guideline and after has been found. The importance of timing of iron administration in low birth weight infants, the effect of probiotics for preventing necrotising enterocolitis and perspectives for managing jaundice and cholestasis in neonates have been highlighted. New strategies have been developed to reduce the risk for relapse in nephrotic syndrome including prednisolone during upper respiratory infection. Insights into the pathophysiology of cerebral palsy, arterial ischemic stroke and acute encephalitis may drive advances in treatment. Recommendations on breastfeeding and complementary feeding have been updated. Novel treatments for rhabdomyosarcoma should be considered for paediatric patients. Control of risk factors for bronchiolitis and administration of pavilizumab for preventing respiratory syncytial virus infection may reduce hospitalization. Identification of risk factors for hospitalization in children with wheezing can improve the management of this disease. Deletions or mutations in genes encoding proteins for surfactant function may cause diffuse lung disease.

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.

Single Gene and Syndromic Causes of Obesity: Illustrative Examples

Obesity is a significant health problem in westernized societies, particularly in the United States where it has reached epidemic proportions in both adults and children. The prevalence of childhood obesity has doubled in the past 30 years. The causation is complex with multiple sources, including an obesity promoting environment with plentiful highly dense food sources and overall decreased physical activity noted for much of the general population, but genetic factors clearly play a role. Advances in genetic technology using candidate gene approaches, genome-wide association studies, structural and expression microarrays, and next generation sequencing have led to the discovery of hundreds of genes recognized as contributing to obesity. Polygenic and monogenic causes of obesity are now recognized including dozens of examples of syndromic obesity with Prader-Willi syndrome, as a classical example and recognized as the most common known cause of life-threatening obesity. Genetic factors playing a role in the causation of obesity will be discussed along with the growing evidence of single genes and the continuum between monogenic and polygenic obesity. The clinical and genetic aspects of four classical but rare obesity-related syndromes (ie, Prader-Willi, Alström, fragile X, and Albright hereditary osteodystrophy) will be described and illustrated in this review of single gene and syndromic causes of obesity.

Prader-Willi Syndrome: A spectrum of anatomical and clinical features

Prader-Willi Syndrome (PWS) is estimated to affect 400,000 people worldwide. First described clinically in 1956, PWS is now known to be a result of a genetic mutation, involving Chromosome 15. The phenotypical appearance of individuals with the syndrome follows a similar developmental course. During infancy, universal hypotonia accompanied by feeding problems, hypogonadism, and dolichocephaly are evident. Characteristic facial features such as narrow bifrontal diameter, almond-shaped eyes, and small mouth (with downturned corners and thin upper lip) may also be evident at this stage. In early childhood, the craniofacial features become more obvious and a global developmental delay is observed. Simultaneously, individuals develop hyperphagia that leads to excessive or rapid weight gain, which, if untreated, exists throughout their lifespan and may predispose them to numerous, serious health issues. The standard tool for differential diagnosis of PWS is genetic screening; however, clinicians also need to be aware of the characteristic features of this disorder, including differences between the genetic subtypes. As the clinical manifestations of the syndrome vary between individuals and become evident at different developmental time points, early assessment is hindered. This article focuses on the clinical and anatomical manifestations of the syndrome and highlights the areas of discrepancy and limitations within the existing literature. Clin. Anat. 29:590-605, 2016. © 2016 Wiley Periodicals, Inc.

Prader-Willi Syndrome: Clinical Genetics and Diagnostic Aspects with Treatment Approaches

BACKGROUND

Prader-Willi syndrome (PWS) is a neuro-developmental genetic disorder due to lack of expression of genes inherited from the paternal chromosome 15q11-q13 region with three main genetic subtypes. These include paternal 15q11-q13 deletion (about 70% of cases), maternal uniparental disomy 15 or both 15s from the mother (20-30% of cases), and defects in the imprinting center (1-3%) which controls the expression of imprinted genes in this chromosome region. Clinical manifestations include infantile hypotonia with a poor suck resulting in failure to thrive, short stature, small hands/feet and hypogonadism/hypogenitalism due to growth and other hormone deficiencies, hyperphagia and excessive weight gain with obesity and cognitive and behavioral problems including obsessive compulsions, tantrums and self-injury. The phenotype is likely related to hypothalamic dysfunction.

OBJECTIVE

Hyperphagia and obesity with related complications are major causes of morbidity and mortality in PWS requiring accurate diagnosis, appropriate medical management and treatment; the major objective of our report.

METHODS AND RESULTS

An extensive review of the literature was undertaken including genetics, clinical and behavioral aspects, and updated health-related information addressing the importance of early diagnosis and treatment of individuals with Prader-Willi syndrome. A searchable, bulleted and formatted list of topics related to this obesity syndrome was provided utilizing a Table of Contents approach for the clinical practitioner.

CONCLUSIONS

Physicians and other health care providers can use this review with clinical, genetic and treatment summaries divided into sections that are pertinent in the context of clinical practice. Finally, frequently asked questions by clinicians, families and other interested participants will be addressed.

Prader-Willi syndrome: a review of clinical, genetic, and endocrine findings

INTRODUCTION

Prader-Willi syndrome (PWS) is a multisystemic complex genetic disorder caused by lack of expression of genes on the paternally inherited chromosome 15q11.2-q13 region. There are three main genetic subtypes in PWS: paternal 15q11-q13 deletion (65-75 % of cases), maternal uniparental disomy 15 (20-30 % of cases), and imprinting defect (1-3 %). DNA methylation analysis is the only technique that will diagnose PWS in all three molecular genetic classes and differentiate PWS from Angelman syndrome. Clinical manifestations change with age with hypotonia and a poor suck resulting in failure to thrive during infancy. As the individual ages, other features such as short stature, food seeking with excessive weight gain, developmental delay, cognitive disability and behavioral problems become evident. The phenotype is likely due to hypothalamic dysfunction, which is responsible for hyperphagia, temperature instability, high pain threshold, hypersomnia and multiple endocrine abnormalities including growth hormone and thyroid-stimulating hormone deficiencies, hypogonadism and central adrenal insufficiency. Obesity and its complications are the major causes of morbidity and mortality in PWS.

METHODS

An extensive review of the literature was performed and interpreted within the context of clinical practice and frequently asked questions from referring physicians and families to include the current status of the cause and diagnosis of the clinical, genetics and endocrine findings in PWS.

CONCLUSIONS

Updated information regarding the early diagnosis and management of individuals with Prader-Willi syndrome is important for all physicians and will be helpful in anticipating and managing or modifying complications associated with this rare obesity-related disorder.

Laparoscopic sleeve gastrectomy in children and adolescents with Prader-Willi syndrome: a matched-control study

BACKGROUND

Obesity is a leading cause of mortality and morbidity in Prader-Willi syndrome (PWS).

OBJECTIVES

To study weight loss and growth after laparoscopic sleeve gastrectomy (LSG) in pediatric patients with PWS compared with those without the syndrome.

SETTING

Academic center with a standardized care pathway for pediatric bariatric surgery as a part of a prospective clinical outcome study on children and adolescents undergoing weight loss surgery.

METHODS

Clinical data of all PWS patients who underwent LSG were abstracted from our prospective database, which included all pediatric patients who underwent bariatric surgery. These data were then compared with a 1:3 non-PWS group matched for age, gender, and body mass index (BMI). Data for up to 5 years follow-up were analyzed.

RESULTS

The 24 PWS patients (mean age 10.7; 6<8 yr old, range 4.9-18) had a preoperative BMI of 46.2 ± 12.2 kg/m(2). All PWS patients had obstructive sleep apnea (OSA), 62% had dyslipidemia, 43% had hypertension, and 29% had diabetes mellitus. BMI change at the first, second, third, fourth, and fifth annual visits was -14.7 (n = 22 patients), -15.0 (n = 18), 12.2 (n = 13), -12.7 (n = 11), and -10.7 (n = 7), respectively, in the PWS group, whereas the non-PWS group had a BMI change of -15.9 (n = 67), -18.0 (n = 50), -18.4 (n = 47), -18.9 (n = 26), and -19.0 (n = 20), respectively. No significant difference was observed in postoperative BMI change (P = .2-.7) or growth (postoperative height z-score P value at each annual visit = .2-.8); 95% of co-morbidities in both groups were in remission or improved, with no significant difference in the rate of co-morbidity resolution after surgery (P = .73). One PWS patient was readmitted 5 years after surgery with recurrence of OSA and heart failure. No other readmissions occurred, and there were no reoperations, postoperative leaks, or other complications. No mortality or major morbidity was observed during the 5 years of follow-up. Among the PWS patients who reached their follow-up visit time points the total follow-up rate was 94.1%, whereas in the non-PWS group it was 97%. All patients who missed a follow-up visit were subsequently seen in future follow-ups, and no patient was lost to follow-up in either group.

CONCLUSIONS

PWS children and adolescents underwent effective weight loss and resolution of co-morbidities after LSG, without mortality, significant morbidity, or slowing of growth. LSG should be offered to obese PWS patients with heightened mortality particularly because no other effective alternative therapy is available.