Down syndrome (DS) is associated with psychomotor retardation, short stature and endocrine dysfunction. Statural growth is a well-known indicator of health. The growth in DS differs markedly from that of other children and there is a 20 cm reduction of final height as compared to target height. We developed growth charts specific for Swedish children with DS, in order to facilitate early diagnosis of concomitant diseases that influence growth. The growth charts are available for paediatricians and child health care professionals in Sweden. The mechanism underlying the impaired growth in DS is unknown. Height is influenced by parental factors, energy intake, hormone balance and general health. In DS, genetic factors deriving from the extra chromosome 21 further affect growth. Children with DS seem to have reasonable levels of growth hormone (GH), even though GH treatment for limited periods of time improves growth velocity. Within the present project, the subjects of a previous study on early GH therapy in DS were followed up regarding late effects. We found a larger adult head circumference and better psychomotor abilities in the previously treated subjects despite a lack of effect on final height. In adult life, GH has effects on psychological well-being and metabolism. The clinical features in adults with DS might indicate impaired GH secretion. Ten young adults with DS were studied and compared with ten healthy controls. The GH secretion in the DS subjects did not differ from that in the controls. The fat body mass percentage was increased in DS, in line with the high prevalence of overweight/obesity. The finding of an increased HOMA index as well as a high relative rate of hepatic glucose production in DS indicates reduced insulin sensitivity both peripherally and in the liver. Thyroid dysfunction is common in DS. There is a 30-fold increase in congenital hypothyroidism, and acquired hypothyroidism has been reported to be present in up to 50% of adults with DS. We collected neonatal screening results and hospital records for the first ten years of life of 68 children with DS. The mean TSH concentration was increased neonatally, indicating marginal hypothyroidism early in life in DS. However, the neonatal TSH level did not predict development of manifest hypothyroidism later in life. / Downs syndrom (DS) är en vanlig kromosomavvikelse. Kortvuxenhet och psykomotorisk utvecklingsstörning är kardinaltecken vid DS. Endokrina avvikelser är också frekvent förekommande. Tillväxt är en bra indikator på barns hälsa. Nyfödda barn med DS är kortare än andra nyfödda, och skillnaden i längd ökar under barndomen. Sjukdomar som påverkar tillväxten upptäcks ofta via ett förändrat tillväxtmönster. Detta kan lätt förbises vid DS eftersom tillväxten redan är avvikande. Användning av syndromspecifika tillväxtkurvor ökar möjligheterna till diagnostik av sjukdomar som stör längdtillväxten. Vi har framställt tillväxtkurvor för barn med DS, vilka finns tillgängliga inom svensk barnsjukvård och barnhälsovård. Längdtillväxt styrs av nedärvda faktorer från föräldrarna liksom av nutrition, hälsa och hormoner. Genetiska faktorer, kopplade till kromosom 21, kan påverka tillväxten vid DS, men tillväxtstörningens exakta bakgrund är inte känd. I vuxen ålder är personer med DS ungefär 20 cm kortare än förväntat med hänsyn till föräldralängder. Trots att barn med DS har relativt normala nivåer av tillväxthormon (STH eller GH) förbättras deras tillväxt vid STH-behandling. Inom avhandlingsarbetet följde vi upp ungdomar med DS, vilka behandlats med STH i tidig barndom. Vi kunde påvisa större huvudomfång samt förbättrad kognitiv och motorisk förmåga, trots avsaknad av effekt på slutlängden. Tillväxthormon har i vuxen ålder effekt både på ämnesomsättning och psykologiskt välbefinnande. Vuxna individer med DS uppvisar flera tecken förenliga med STH-brist. Vi jämförde tio unga vuxna med DS med tio friska kontrollindivider avseende förmågan att insöndra STH. STH-insöndringen hos individerna med DS skiljde sig inte från den hos kontrollerna. Vid samtidig undersökning av kroppssammansättning påvisades en ökad andel kroppsfett hos individerna med DS, resultat i linje med den frekventa förekomsten av övervikt/fetma. Individerna med DS hade en förhöjd glukosproduktion, som tillsammans med ett ökat HOMA-index talar för förekomst av minskad insulinkänslighet både på levernivå och perifert. Brist på sköldkörtelhormon är mycket vanligt vid DS och upp till hälften av vuxna med DS kan ha hypotyreos. Vi studerade 68 barn med DS avseende nivåer av tyroideastimulerande hormon (TSH) vid PKU-provtagning. Vi följde också barnens journalhandlingar från de tio första levnadsåren i syfte att undersöka om den neonatala TSH-nivån kan prediktera framtida underfunktion av sköldkörteln. Resultaten visade att barn med DS har en förhöjd nivå av TSH neonatalt, vilket indikerar en brist på sköldkörtelhormon redan i nyföddhetsperioden, men nivån förutsäger inte utveckling av manifest hypotyreos senare under barndomen.

Introduction: The epidemic of overweight and obesity both worldwide and in Canada is indicative of the need for proper growth monitoring beginning at birth. This study evaluated Family Physician’s (FP) Level of Use (LoU) of the recommended 2006 and 2007 World Health Organization (WHO) Growth Charts for monitoring their paediatric patients’ growth. It explored factors influencing LoU, utilizing the Diffusion of Innovations (DOI) theory and Ecological Framework for Effective Implementation (EFEI) as guiding models. FPs’ awareness of resources to support paediatric weight management was also assessed. Methods: A survey was distributed to FP in British Columbia (BC), Canada (N = 2853). The survey addressed provider and innovation characteristics, prevention delivery and support system factors, and barriers and facilitators to chart use. Correlations and multiple linear regression were used to determine correlates and predictors of LoU. Results: Sixty-two surveys were returned (2.2%). WHO Growth Chart LoU was 80.4%. Six variables significantly predicted LoU, including age (β = -.28, t = -3.15, p < .05), practicing in Fraser Health Authority region (β = -.24, t = -2.67, p < .05), assessing head circumference of birth to two year olds (β = .23, t = 2.45, p < .05), perceived growth chart accessibility (β = .39, t = 4.22, p < .05) and compatibility (β = .47, t = 5.27, p < .05), and innovativeness (β = -.37, t = -4.11, p < .05). These variables accounted for 69% of the variance in LoU. The most commonly identified barrier and facilitator to chart use was related to the Electronic Medical Record (EMR) system. FPs’ awareness of resources to support overweight paediatric patients was low. Conclusion: The majority of FP in BC in this sample had adopted the WHO Growth Charts. The results showed partial support for DOI theory and EFEI derived factors. Despite a small sample size, the findings highlighted the importance of installing the charts in the EMR systems, and can provide a foundation for future public health dissemination efforts and research on medical guideline implementation. / Graduate / 0573 / 0769 / erand@uvic.ca

Introduction: The epidemic of overweight and obesity both worldwide and in Canada is indicative of the need for proper growth monitoring beginning at birth. This study evaluated Family Physician’s (FP) Level of Use (LoU) of the recommended 2006 and 2007 World Health Organization (WHO) Growth Charts for monitoring their paediatric patients’ growth. It explored factors influencing LoU, utilizing the Diffusion of Innovations (DOI) theory and Ecological Framework for Effective Implementation (EFEI) as guiding models. FPs’ awareness of resources to support paediatric weight management was also assessed. Methods: A survey was distributed to FP in British Columbia (BC), Canada (N = 2853). The survey addressed provider and innovation characteristics, prevention delivery and support system factors, and barriers and facilitators to chart use. Correlations and multiple linear regression were used to determine correlates and predictors of LoU. Results: Sixty-two surveys were returned (2.2%). WHO Growth Chart LoU was 80.4%. Six variables significantly predicted LoU, including age (β = -.28, t = -3.15, p < .05), practicing in Fraser Health Authority region (β = -.24, t = -2.67, p < .05), assessing head circumference of birth to two year olds (β = .23, t = 2.45, p < .05), perceived growth chart accessibility (β = .39, t = 4.22, p < .05) and compatibility (β = .47, t = 5.27, p < .05), and innovativeness (β = -.37, t = -4.11, p < .05). These variables accounted for 69% of the variance in LoU. The most commonly identified barrier and facilitator to chart use was related to the Electronic Medical Record (EMR) system. FPs’ awareness of resources to support overweight paediatric patients was low. Conclusion: The majority of FP in BC in this sample had adopted the WHO Growth Charts. The results showed partial support for DOI theory and EFEI derived factors. Despite a small sample size, the findings highlighted the importance of installing the charts in the EMR systems, and can provide a foundation for future public health dissemination efforts and research on medical guideline implementation. / Graduate / 0573 / 0769 / erand@uvic.ca

A Síndrome de Noonan (SN) é caracterizada por baixa estatura proporcionada de início pós-natal, dismorfismos faciais, cardiopatia congênita e deformidade torácica. A frequência da SN é estimada entre 1:1000 e 1:2500 nascidos vivos, com distribuição semelhante em ambos os sexos. A herança é autossômica dominante com penetrância completa, porém a maioria dos casos é esporádica. Até o momento, mutações em genes da via RAS-MAPK (PTPN11, KRAS, SOS1, RAF1, MEK1, NRAS e SHOC2) foram identificadas em aproximadamente 70% dos pacientes. Uma das principais características fenotípicas da SN é a baixa estatura pós-natal, embora o mecanismo fisiopatológico do déficit de crescimento nesta síndrome ainda não esteja totalmente esclarecido. Estudos que avaliaram o padrão de crescimento linear em crianças com SN foram realizados anteriormente ao conhecimento do diagnóstico molecular dessa síndrome. No presente estudo, avaliamos a frequência de mutação nos genes PTPN11, SOS1, RAF1 e KRAS em 152 pacientes com SN e o padrão de crescimento linear (altura) e ponderal [índice de massa corpórea (IMC)] dos pacientes com mutação identificada. No total, mutações nos genes relacionados foram encontradas em 99 pacientes (65%) do nosso estudo, com predominância do gene PTPN11 (47%), seguido do SOS1 (9%), RAF1 (7%) e KRAS (3%). Foram construídas curvas específicas para SN de Altura e IMC para idade e sexo utilizando o método LMS. Os pacientes com SN apresentaram crescimento pré-natal preservado, porém o comprometimento do crescimento pós-natal foi observado desde o primeiro ano de vida, atingindo uma altura final de -2,5 e -2,2 desvios-padrão da média para população brasileira em homens e mulheres, respectivamente. O prejuízo da altura foi maior nos pacientes com mutação no gene RAF1 em comparação com os genes PTPN11 e SOS1. O IMC dos pacientes com SN apresentou queda de 1 desvio-padrão em relação à média da população brasileira normal. O comprometimento do IMC foi menor nos pacientes carreadores de mutação no RAF1. Pacientes com mutação nos genes PTPN11 e SOS1 apresentaram maior frequência de estenose de valva pulmonar, enquanto a miocardiopatia hipertrófica foi mais frequente nos pacientes com mutação no gene RAF1. A variabilidade fenotípica observada nos pacientes com mutação no PTPN11 não pode ser explicada pelo grau que estas mutações influenciam a atividade tirosina fosfatase da SHP-2 nem pela presença de polimorfismos no gene KRAS. Com a análise dos éxons 3, 8 e 13 do PTPN11, seguido dos éxons 6 e 10 do SOS1 e éxon 7 do RAF1 identificamos 86% dos pacientes carreadores de mutações nos genes relacionados, propondo uma forma mais eficiente de avaliação molecular na SN. Acreditamos que a variabilidade fenotípica presente nessa síndrome esteja diretamente ligada aos diferentes papéis exercidos pelas proteínas que participam da via RAS/MAPK. Entretanto, mais estudos em relação à via RAS/MAPK serão necessários para esclarecer as questões relacionadas ao crescimento e outras características fenotípicas da SN / Noonan Syndrome (NS) is characterized by distinctive facial features, short stature and congenital heart defects. The estimated prevalence is 1:1000 to 1:2500 live births, affecting equally both sexes. It is an autosomal dominant disorder with complete penetrance, but most cases are sporadic. To date, mutations in the RAS/MAPK pathway genes (PTPN11, KRAS, SOS1, RAF1, MEK1, NRAS and SHOC2) were identified in approximately 70% of patients. One of the cardinal signs of NS is proportional postnatal short stature although the physiopathological mechanism of growth impairment remains unclear. The current knowledge about the natural history of growth associated with NS was described before molecular diagnosis era. In this study, we performed PTPN11, SOS1, RAF1, and KRAS mutation analysis in a cohort of 152 NS patients and studied the natural linear (height) and ponderal growth [body mass index (BMI)] of NS patients with related mutations. Mutations in NS-causative genes were found in 99 patients (65%) of our cohort. The most common mutated gene was PTPN11 (47%), followed by SOS1 (9%), RAF1 (7%) and KRAS (3%). Sex-specific percentile curves for height and BMI were constructed using the LMS method. NS patients had birth weight and length within normal ranges but the postnatal growth impairment was observed during the first year of life, reaching a final height of -2.3 and -2.2 standard deviations from the mean for Brazilian healthy men and women, respectively. Postnatal growth impairment was higher in RAF1 mutation patients than in patients with SOS1 and PTPN11 mutations. BMI values in NS patients were lower in comparison with normal Brazilian population. BMI values were higher in patients with RAF1 mutations than in patients with other genotypes. Patients with mutations in PTPN11 and SOS1 genes were more likely to have pulmonary valve stenosis, whereas hypertrophic cardiomyopathy was more common in patients with mutations in the gene RAF1. The intensity of constitutive tyrosine phosphatase activity of SHP-2 due to PTPN11 mutations, as well as the presence of polymorphisms in KRAS gene did not influence the phenotype of NS patients with mutation in PTPN11 gene. Analysis of exons 3, 8 and 13 of PTPN11 gene, followed by exons 6 and 10 of SOS1 gene and exon 7of RAF1 gene identified 86% of patients harboring mutations in related genes, suggesting a more efficient evaluation of NS molecular diagnosis. We believe that the phenotypic variability in this syndrome is directly linked to the different roles played by proteins that participate in RAS/MAPK pathway. However, further studies in RAS/MAPK pathway are needed to clarify issues related to growth and other phenotypic characteristics of SN

A Síndrome de Noonan (SN) é caracterizada por baixa estatura proporcionada de início pós-natal, dismorfismos faciais, cardiopatia congênita e deformidade torácica. A frequência da SN é estimada entre 1:1000 e 1:2500 nascidos vivos, com distribuição semelhante em ambos os sexos. A herança é autossômica dominante com penetrância completa, porém a maioria dos casos é esporádica. Até o momento, mutações em genes da via RAS-MAPK (PTPN11, KRAS, SOS1, RAF1, MEK1, NRAS e SHOC2) foram identificadas em aproximadamente 70% dos pacientes. Uma das principais características fenotípicas da SN é a baixa estatura pós-natal, embora o mecanismo fisiopatológico do déficit de crescimento nesta síndrome ainda não esteja totalmente esclarecido. Estudos que avaliaram o padrão de crescimento linear em crianças com SN foram realizados anteriormente ao conhecimento do diagnóstico molecular dessa síndrome. No presente estudo, avaliamos a frequência de mutação nos genes PTPN11, SOS1, RAF1 e KRAS em 152 pacientes com SN e o padrão de crescimento linear (altura) e ponderal [índice de massa corpórea (IMC)] dos pacientes com mutação identificada. No total, mutações nos genes relacionados foram encontradas em 99 pacientes (65%) do nosso estudo, com predominância do gene PTPN11 (47%), seguido do SOS1 (9%), RAF1 (7%) e KRAS (3%). Foram construídas curvas específicas para SN de Altura e IMC para idade e sexo utilizando o método LMS. Os pacientes com SN apresentaram crescimento pré-natal preservado, porém o comprometimento do crescimento pós-natal foi observado desde o primeiro ano de vida, atingindo uma altura final de -2,5 e -2,2 desvios-padrão da média para população brasileira em homens e mulheres, respectivamente. O prejuízo da altura foi maior nos pacientes com mutação no gene RAF1 em comparação com os genes PTPN11 e SOS1. O IMC dos pacientes com SN apresentou queda de 1 desvio-padrão em relação à média da população brasileira normal. O comprometimento do IMC foi menor nos pacientes carreadores de mutação no RAF1. Pacientes com mutação nos genes PTPN11 e SOS1 apresentaram maior frequência de estenose de valva pulmonar, enquanto a miocardiopatia hipertrófica foi mais frequente nos pacientes com mutação no gene RAF1. A variabilidade fenotípica observada nos pacientes com mutação no PTPN11 não pode ser explicada pelo grau que estas mutações influenciam a atividade tirosina fosfatase da SHP-2 nem pela presença de polimorfismos no gene KRAS. Com a análise dos éxons 3, 8 e 13 do PTPN11, seguido dos éxons 6 e 10 do SOS1 e éxon 7 do RAF1 identificamos 86% dos pacientes carreadores de mutações nos genes relacionados, propondo uma forma mais eficiente de avaliação molecular na SN. Acreditamos que a variabilidade fenotípica presente nessa síndrome esteja diretamente ligada aos diferentes papéis exercidos pelas proteínas que participam da via RAS/MAPK. Entretanto, mais estudos em relação à via RAS/MAPK serão necessários para esclarecer as questões relacionadas ao crescimento e outras características fenotípicas da SN / Noonan Syndrome (NS) is characterized by distinctive facial features, short stature and congenital heart defects. The estimated prevalence is 1:1000 to 1:2500 live births, affecting equally both sexes. It is an autosomal dominant disorder with complete penetrance, but most cases are sporadic. To date, mutations in the RAS/MAPK pathway genes (PTPN11, KRAS, SOS1, RAF1, MEK1, NRAS and SHOC2) were identified in approximately 70% of patients. One of the cardinal signs of NS is proportional postnatal short stature although the physiopathological mechanism of growth impairment remains unclear. The current knowledge about the natural history of growth associated with NS was described before molecular diagnosis era. In this study, we performed PTPN11, SOS1, RAF1, and KRAS mutation analysis in a cohort of 152 NS patients and studied the natural linear (height) and ponderal growth [body mass index (BMI)] of NS patients with related mutations. Mutations in NS-causative genes were found in 99 patients (65%) of our cohort. The most common mutated gene was PTPN11 (47%), followed by SOS1 (9%), RAF1 (7%) and KRAS (3%). Sex-specific percentile curves for height and BMI were constructed using the LMS method. NS patients had birth weight and length within normal ranges but the postnatal growth impairment was observed during the first year of life, reaching a final height of -2.3 and -2.2 standard deviations from the mean for Brazilian healthy men and women, respectively. Postnatal growth impairment was higher in RAF1 mutation patients than in patients with SOS1 and PTPN11 mutations. BMI values in NS patients were lower in comparison with normal Brazilian population. BMI values were higher in patients with RAF1 mutations than in patients with other genotypes. Patients with mutations in PTPN11 and SOS1 genes were more likely to have pulmonary valve stenosis, whereas hypertrophic cardiomyopathy was more common in patients with mutations in the gene RAF1. The intensity of constitutive tyrosine phosphatase activity of SHP-2 due to PTPN11 mutations, as well as the presence of polymorphisms in KRAS gene did not influence the phenotype of NS patients with mutation in PTPN11 gene. Analysis of exons 3, 8 and 13 of PTPN11 gene, followed by exons 6 and 10 of SOS1 gene and exon 7of RAF1 gene identified 86% of patients harboring mutations in related genes, suggesting a more efficient evaluation of NS molecular diagnosis. We believe that the phenotypic variability in this syndrome is directly linked to the different roles played by proteins that participate in RAS/MAPK pathway. However, further studies in RAS/MAPK pathway are needed to clarify issues related to growth and other phenotypic characteristics of SN