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Haugen G, Rønnestad A, Kroken M. Variations in fetal phenotype in Prader-Willi syndrome. Prenat Diagn 2009; 29:294. [PMID: 19248040 DOI: 10.1002/pd.2207] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Sasaki A, Hinck L, Watanabe K. RumMAGE-D the Members: Structure and Function of a New Adaptor Family of MAGE-D Proteins. J Recept Signal Transduct Res 2008; 25:181-98. [PMID: 16194933 DOI: 10.1080/10799890500210511] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
MAGE genes were first described as cancer-testis antigens, which are silenced in normal adult tissues but aberrantly expressed in tumor cells. The short peptides, derived from the degradation of MAGE transcripts, are the source of antigens that cause tumor rejection reactions when presented in the context of major histocompatibility complex. The recent discovery of a subset of genes that contain the structurally conserved MAGE homology domain (MHD) has accelerated the investigation into the normal function of MAGE genes. This new type of MAGE gene is normally expressed in embryonal and adult tissue, especially the brain. MAGE-D1, also known as NRAGE or Dlxin-1, functions as an adaptor protein that mediates multiple signaling pathways, including NGFR (p75NTR) and UNC5H1-induced apoptosis and Dlx/Msx-mediated transcription. Loss of a different MAGE family member, Necdin, which works as a cell cycle regulator, may play a role in the pathogenesis of Prader-Willi syndrome, a neurobehavioral disorder. In this article, the authors discuss recent findings concerning the structure and function of new MAGE genes, primarily focusing on MAGE-D1. Because some MAGE-D subfamily proteins share significant homology within the MHD, these recent discoveries on MAGE-D1 may give insight into the function of other MAGE-D proteins.
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Iughetti L, Bosio L, Corrias A, Gargantini L, Ragusa L, Livieri C, Predieri B, Bruzzi P, Caselli G, Grugni G. Pituitary height and neuroradiological alterations in patients with Prader-Labhart-Willi syndrome. Eur J Pediatr 2008; 167:701-2. [PMID: 17805568 DOI: 10.1007/s00431-007-0555-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2007] [Accepted: 06/12/2007] [Indexed: 11/24/2022]
Abstract
Prader-Willi syndrome (PWS), a genetic disorder due to an alteration in the paternally derived long arm of chromosome 15, is characterized by a complex clinical picture (short stature, obesity, hypogonadism) that seems to be referable to as a central hypothalamic/pituitary dysfunction. To determine whether there is any diminution in the anterior pituitary gland or other neuroradiological alterations, we retrospectively analysed 91 patients with PWS (42 females, 49 males; age range: 0.7-16.8 years) by cerebral magnetic resonance imaging (MRI). Of these 91 patients, MRI analysis showed a reduction in pituitary height in 45 patients (49.4%), a complete absence of the posterior pituitary bright spot in six patients (6.6%) and other neuroradiological alterations in ten patients (11%). Altogether, neuroradiological alterations were present in 61 of the 91 (67%) patients. Our results indicate that neuroradiological alterations are more frequent in PWS patients than has been reported to date.
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Ding F, Li HH, Zhang S, Solomon NM, Camper SA, Cohen P, Francke U. SnoRNA Snord116 (Pwcr1/MBII-85) deletion causes growth deficiency and hyperphagia in mice. PLoS One 2008. [PMID: 18320030 DOI: 10.1371/journal.pone.001709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023] Open
Abstract
Prader-Willi syndrome (PWS) is the leading genetic cause of obesity. After initial severe hypotonia, PWS children become hyperphagic and morbidly obese, if intake is not restricted. Short stature with abnormal growth hormone secretion, hypogonadism, cognitive impairment, anxiety and behavior problems are other features. PWS is caused by lack of expression of imprinted genes in a approximately 4 mb region of chromosome band 15q11.2. Our previous translocation studies predicted a major role for the C/D box small nucleolar RNA cluster SNORD116 (PWCR1/HBII-85) in PWS. To test this hypothesis, we created a approximately 150 kb deletion of the > 40 copies of Snord116 (Pwcr1/MBII-85) in C57BL/6 mice. Snord116del mice with paternally derived deletion lack expression of this snoRNA. They have early-onset postnatal growth deficiency, but normal fertility and lifespan. While pituitary structure and somatotrophs are normal, liver Igf1 mRNA is decreased. In cognitive and behavior tests, Snord116del mice are deficient in motor learning and have increased anxiety. Around three months of age, they develop hyperphagia, but stay lean on regular and high-fat diet. On reduced caloric intake, Snord116del mice maintain their weight better than wild-type littermates, excluding increased energy requirement as a cause of hyperphagia. Normal compensatory feeding after fasting, and ability to maintain body temperature in the cold indicate normal energy homeostasis regulation. Metabolic chamber studies reveal that Snord116del mice maintain energy homeostasis by altered fuel usage. Prolonged mealtime and increased circulating ghrelin indicate a defect in meal termination mechanism. Snord116del mice, the first snoRNA deletion animal model, reveal a novel role for a non-coding RNA in growth and feeding regulation.
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Miller JL, Goldstone AP, Couch JA, Shuster J, He G, Driscoll DJ, Liu Y, Schmalfuss IM. Pituitary abnormalities in Prader–Willi syndrome and early onset morbid obesity. Am J Med Genet A 2008; 146A:570-7. [PMID: 17431897 DOI: 10.1002/ajmg.a.31677] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Prader-Willi syndrome (PWS) is a well-defined syndrome of childhood-obesity which can serve as a model for investigating early onset childhood obesity. Many of the clinical features of PWS (e.g., hyperphagia, hypogonadotropic hypogonadism, growth hormone deficiency) are hypothesized to be due to abnormalities of the hypothalamus and/or pituitary gland. Children who become severely obese very early in life (i.e., before age 4 years) may also have a genetic etiology of their obesity, perhaps with associated neuroendocrine and hypothalamo-pituitary defects, as infants and very young children have limited access to environmental factors that contribute to obesity. We hypothesized that morphologic abnormalities of the pituitary gland would be seen in both individuals with PWS and other subjects with early onset morbid obesity (EMO). This case-control study included individuals with PWS (n = 27, age 3 months to 39 years), patients with EMO of unknown etiology (n = 16, age 4-22 years; defined as body mass index greater than the 97th centile for age before age 4 years), and normal weight siblings (n = 25, age 7 months to 43 years) from both groups. Participants had 3-dimensional magnetic resonance imaging to evaluate the pituitary gland, a complete history and physical examination, and measurement of basal pituitary hormones. Subjects with PWS and EMO had a higher prevalence of pituitary morphological abnormalities than did control subjects (74% PWS, 69% EMO, 8% controls; P < 0.001). Anterior pituitary hormone deficiencies were universal in individuals with PWS (low IGF-1 in 100%, P < 0.001 PWS vs. controls; central hypothyroidism in 19%, P = 0.052, and hypoplastic genitalia or hypogonadotropic hypogonadism in 100%, P < 0.001), and was often seen in individuals with EMO (6%, P = 0.89 vs. control, 31%, P = 0.002, and 25%, P = 0.018, respectively). The presence of a hypoplastic pituitary gland appeared to correlate with the presence of anterior pituitary hormone deficiencies in individuals with EMO, but no correlation was apparent in individuals with PWS. In conclusion, the high frequency of both morphological and hormonal abnormalities of the pituitary gland in both individuals with PWS and EMO suggests that abnormalities in the hypothalamo-pituitary axis are features not only of PWS, but also frequently of EMO of unknown etiology.
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Abstract
The past decade has seen tremendous advances in our understanding of the molecular and genetic basis of many neuropsychiatric disorders. Although the genetic aberrations that lead to these syndromes have been identified in many cases, not much is known about specific gene products and their function. This article reviews the molecular basis of well-known neurogenetic disorders. The syndromes discussed here follow a Mendelian pattern of inheritance and are predominantly single-gene disorders; however, most childhood and adolescent psychiatric disorders are polygenic in nature. This genetic complexity and heterogeneity has made it difficult to identify the genes involved in their etiology. Identification of genetic and environmental risk factors involved in the etiology of complex disorders, such as autism, will help in the discovery of medications that can ameliorate the symptoms.
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Diene G, Postel-Vinay A, Pinto G, Polak M, Tauber M. [The Prader-Willi syndrome]. ANNALES D'ENDOCRINOLOGIE 2007; 68:129-37. [PMID: 17499572 DOI: 10.1016/j.ando.2007.03.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Prader-Willi syndrome is a rare genetic disorder, affecting 1 out of 25,000 births, in which a critical region of chromosome 15, the 15q11-q13 region, is affected. At birth, PWS infants exhibit severe hypotonia that partially improves, explaining in part suckling and swallowing troubles and the delay in psychomotor development. Characteristic facial features (dysmorphic syndrome) and very small hands and feet are frequently observed at this age. After this initial phase, the most striking signs appear: hyperphagia and absence of satiety often leading to severe obesity in affected children as young as two years. The situation may deteriorate quickly without adequate outside controls and explains in great part the morbidity and mortality of these patients. Other endocrine abnormalities in association with the hypothalamic-pituitary abnormalities contribute to the clinical picture of short stature due to a growth hormone deficiency and incomplete pubertal development. The degree of cognitive dysfunction varies widely from one child to another. It is associated with learning disabilities and impaired speech and language development worsened by psychological and behavioural troubles. The expert consensus is that diagnosis should be based on clinical criteria (Holm's criteria of 1993, revised in 2001) with confirmation by genetic study. Most cases are sporadic and familial cases are rare, those informations should be given as genetic counselling. It is necessary to set up a global and multidisciplinary management. Early diagnosis, early multidisciplinary care and growth hormone treatment have greatly improved the quality of life of these children. We have no long-term data on the effect of GH treatment in adults, on behavioural troubles and autonomy of the persons. In adults, complications particularly linked to obesity and problems of autonomy are still very important.
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Miller JL, Couch JA, Schmalfuss I, He G, Liu Y, Driscoll DJ. Intracranial abnormalities detected by three-dimensional magnetic resonance imaging in Prader-Willi syndrome. Am J Med Genet A 2007; 143A:476-83. [PMID: 17103438 DOI: 10.1002/ajmg.a.31508] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The neuropathologic abnormalities associated with Prader-Willi syndrome (PWS) are largely unknown. PWS is due to the loss of several paternally expressed genes in chromosome 15q11-q13 region. Several of the imprinted genes in the 15q11-q13 region are normally expressed in the brain and thought to be necessary for neuronal growth and development. Thus, we hypothesized that we would find abnormalities in gray and white matter growth in individuals with PWS. We evaluated three-dimensional (3-D) MRI scans of 20 individuals with PWS, aged three months to 39 years, and compared them to 3-D MRI scans of 21 normal weight sibling controls and 16 individuals with early-onset morbid obesity (EMO) of unknown etiology. The interpreters of the scans were blinded to the diagnosis of the subjects. Intracranial abnormalities in individuals with PWS included ventriculomegaly (100% of individuals), decreased volume of brain tissue in the parietal-occipital lobe (50%), sylvian fissure polymicrogyria (60%), and incomplete insular closure (65%). None of the EMO or normal weight control subjects had any of these findings. We found multiple morphologic brain abnormalities in subjects with PWS suggesting that the loss of paternally expressed genes in chromosome 15q11-q13 region may result in abnormalities of neuronal development. The specific mechanisms underlying these neuropathological abnormalities and their correlation with the clinical phenotype remain to be elucidated.
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Galassetti P, Saetrum Opgaard O, Cassidy SB, Pontello A. Nutrient intake and body composition variables in Prader-Willi syndrome--effect of growth hormone supplementation and genetic subtype. J Pediatr Endocrinol Metab 2007; 20:491-500. [PMID: 17550213 DOI: 10.1515/jpem.2007.20.4.491] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
UNLABELLED In patients with Prader-Willi syndrome (PWS), limited information exists on the effects of growth hormone (GH) therapy, gender and genetic subtype on nutrient intake and body composition. We therefore compared GH-treated and nontreated patients, taking into account Tanner stage, gender, and genetic form. PATIENTS AND METHODS In 37 individuals with PWS (20/17 M/F; 21/16 GH+/GH-), dietary intake and body composition (BMI, DEXA) were assessed. RESULTS Older GH-treated children (Tanner stage 3-4) displayed improved body composition variables (BMI, total and percentage fat mass, truncal fat) (p < 0.05), despite dietary intake similar to non-treated patients; younger children (Tanner stage 1-2) displayed a different pattern, despite greater total caloric and fat intake (p < 0.05) with GH treatment, with only minor differences in body composition. Genetic form and gender had no intrinsic effect on nutrient intake or body composition. CONCLUSION In 37 patients with PWS, GH treatment selectively affected body composition (BMI, fat mass), and dietary fat intake based on patients' developmental status, while these variables were unaffected by gender or genetic subtype.
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Camprubí C, Coll MD, Villatoro S, Gabau E, Kamli A, Martínez MJ, Poyatos D, Guitart M. Imprinting center analysis in Prader–Willi and Angelman syndrome patients with typical and atypical phenotypes. Eur J Med Genet 2007; 50:11-20. [PMID: 17095305 DOI: 10.1016/j.ejmg.2006.10.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Accepted: 10/04/2006] [Indexed: 11/22/2022]
Abstract
Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are genetic disorders caused by a deficiency of imprinted gene expression from the paternal or maternal chromosome 15, respectively. This deficiency is due to the deletion of the 15q11-q13 region, parental uniparental disomy of the chromosome 15, or imprinting defect (ID). Mutation of the UBE3A gene causes approximately 10% of AS cases. In this present study, we describe the molecular analysis and phenotypes of two PWS patients and four AS patients with ID. One of the PWS patients has a non-familial imprinting center (IC) deletion and displayed a severe phenotype with an atypical PWS appearance, hyperactivity and psychiatric vulnerability. The other PWS and AS patients did not present genetic abnormalities in the IC, suggesting an epimutation as the genetic cause. The methylation pattern of two AS patients showed a faint maternal band corresponding to a mosaic ID. One of these mosaic patients displayed a mild AS phenotype while the other displayed a PWS-like phenotype.
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Shu SG, Chien S, Wu YC, Tsai PL, Yih JK. Anthropometric and Intellectual Evaluation of Individuals with Prader-Willi Syndrome. J Formos Med Assoc 2007; 106:509-12. [PMID: 17588847 DOI: 10.1016/s0929-6646(09)60303-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Prader-Willi syndrome (PWS) is a rare, multifaceted genetic disorder resulting from the absence of normally active paternally expressed genes from the 15q11-q13 chromosome region. Due to a lack of anthropometric and intellectual data in Taiwan, we attempted these evaluations. Twenty patients (14 males/6 females) aged 7-23 years with molecularly confirmed PWS were enrolled with parental consent. Their mean height standard deviation score (SDS) was -1.26 +/- 1.89 (from -4.3 to +2.16); mean weight SDS was +1.77 +/- 2.00 (from -0.44 to +5.89); mean body mass index SDS was +3.84 +/- 10.54 (from -0.08 to +10.48); and mean body fat tissue SDS was 39.4 +/- 10.54% (14.7-57.8%) by an InBody 3.0 analyzer. All were hypogonadal. Nine of them had once been given growth hormone therapy, and were taller and slimmer than the rest. Their intelligence tests showed full intelligence quotient = 52.0 +/- 7.6; verbal intelligence quotient = 55.9 +/- 8.77; performance intelligence quotient = 53.2 +/- 9.0. Chronic health status revealed that diabetes was prevalent among the older population. Their IQ was in the range of those with moderate retardation.
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Yamada K, Matsuzawa H, Uchiyama M, Kwee IL, Nakada T. Brain developmental abnormalities in Prader-Willi syndrome detected by diffusion tensor imaging. Pediatrics 2006; 118:e442-8. [PMID: 16882785 DOI: 10.1542/peds.2006-0637] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE The purpose of this work was to detect brain developmental abnormalities in Prader-Willi syndrome by using diffusion tensor imaging based on a high-field MRI system. METHODS Eight patients with Prader-Willi syndrome and 8 age- and gender-matched normal control subjects were examined using a high-field (3.0 T) MRI system. Trace value and fractional anisotropy were assessed simultaneously in multiple representative brain regions: the deep gray matter (putamen, caudate head, and dorsomedial thalamus) and the white matter structures (frontal and parietal white matter, posterior limb of internal capsule, and corpus callosum). RESULTS In Prader-Willi syndrome patients, trace value was found to be significantly higher in the left frontal white matter and the left dorsomedial thalamus, whereas fractional anisotropy was significantly reduced in the posterior limb of the internal capsule bilaterally, the right frontal white matter, and the splenium of the corpus callosum. The observed diffusivity characteristics indicate developmental abnormalities in these areas, which are highly consistent with the clinical features of Prader-Willi syndrome. CONCLUSIONS The study provides the first objective evidence that Prader-Willi syndrome patients indeed have developmental abnormalities in specific areas of the brain, providing a new window toward understanding the pathophysiology of Prader-Willi syndrome.
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Krochik AG, Ozuna B, Torrado M, Chertkoff L, Mazza C. Characterization of alterations in carbohydrate metabolism in children with Prader-Willi syndrome. J Pediatr Endocrinol Metab 2006; 19:911-8. [PMID: 16995571 DOI: 10.1515/jpem.2006.19.7.911] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To study carbohydrate metabolism and insulin sensitivity and secretion in children and adolescents with Prader-Willi syndrome (PWS) compared with multifactorial obesity (MO) controls. PATIENTS AND METHODS Seventy-five patients with PWS and 395 controls with MO were studied by oral glucose tolerance test. Insulin resistance (IR) and beta-cell function were assessed by homeostasis model assessment (HOMA), insulin glucose index, fasting insulin and insulin sensitivity index. RESULTS The incidence of diabetes mellitus was 0% in PWS and 1.5% in MO, while carbohydrate intolerance was 9.3% in the former group and 7.6% in the latter (NS); basal insulin level (12 +/- 8.2 vs 22.3 +/- 25 mU/ml) and HOMA-IR (2.47 +/- 1.6 vs 4.18 +/- 5.05) were lower in PWS (p = 0.004 and 0.04, respectively), whereas HOMA beta-cell index was lower in PWS than in MO (59 +/- 42 vs 102 +/- 119, p = 0.03). ISI Composite was higher in PWS compared to MO (6 +/- 5.7 vs 4.18 +/- 5.05, p = 0.04). CONCLUSION Patients with PWS presented lower insulin resistance and a dissociation between beta-cell secretion and the degree of obesity.
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Titomanlio L, De Brasi D, Romano A, Genesio R, Diano AA, Del Giudice E. Partial cerebellar hypoplasia in a patient with Prader-Willi syndrome. Acta Paediatr 2006; 95:861-3. [PMID: 16801186 DOI: 10.1080/08035250500527307] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
UNLABELLED We report a 3-y-old male infant with Prader-Willi syndrome (PWS) caused by a de novo interstitial deletion of 15q11-q13. Additional features included a right cerebellar hemisphere hypoplasia. The extent of deletion was determined by FISH analysis using an SNRPN PW/AS probe that maps in the PWS/AS critical region (CR) and with specific 15q BACs. We unravelled an interstitial 15q11.2-q13.1 deletion spanning about 3 Mb. CONCLUSION To date only a few other PWS patients--including autopsy cases--with CNS structural anomalies have been described. Our case report adds knowledge to the issue of brain involvement in Prader-Willi syndrome. Further MRI studies of PWS patients will be helpful to clarify a correlation between PWS and brain abnormalities.
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Kim SE, Jin DK, Cho SS, Kim JH, Hong SD, Paik KH, Oh YJ, Kim AH, Kwon EK, Choe YH. Regional cerebral glucose metabolic abnormality in Prader-Willi syndrome: A 18F-FDG PET study under sedation. J Nucl Med 2006; 47:1088-1092. [PMID: 16818941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023] Open
Abstract
UNLABELLED Prader-Willi syndrome (PWS) is a genetic disorder caused by the nonexpression of paternal genes in the PWS region of chromosome 15q11-13 and is the most common cause of human syndromic obesity. METHODS We investigated regional brain metabolic impairment in children with PWS by 18F-FDG PET. Sixteen children with PWS (9 males, 7 females; mean age +/- SD, 4.2 +/- 1.1 y) and 7 healthy children (4 males, 3 females; mean age +/- SD, 4.0 +/- 1.7 y) underwent brain 18F-FDG PET in the resting state. The images of PWS children were compared using statistical parametric mapping analysis with those of healthy children in a voxelwise manner. RESULTS Group comparison showed that children with PWS had decreased glucose metabolism in the right superior temporal gyrus and left cerebellar vermis, regions that are associated with taste perception/food reward and cognitive and emotional function, respectively. Metabolism was increased in the right orbitofrontal, bilateral middle frontal, right inferior frontal, left superior frontal, and bilateral anterior cingulate gyri, right temporal pole, and left uncus, regions that are involved in cognitive functions related to eating or obsessive-compulsive behavior. Interestingly, no significant metabolic abnormality was found in the hypothalamus, the brain region believed to be most involved in energy intake and expenditure. CONCLUSION This study describes the neural substrate underlying the abnormal eating behavior and psychobehavioral problems of PWS.
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Choe YH, Song SY, Paik KH, Oh YJ, Chu SH, Yeo SH, Kwon EK, Kim EM, Rha MY, Jin DK. Increased density of ghrelin-expressing cells in the gastric fundus and body in Prader-Willi syndrome. J Clin Endocrinol Metab 2005; 90:5441-5. [PMID: 15956087 DOI: 10.1210/jc.2004-1935] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
CONTEXT The levels of ghrelin, an orexigenic hormone secreted by oxyntic cells in the digestive tract, are elevated in Prader-Willi syndrome (PWS) and GH deficiency (GHD) patients. In this study, we hypothesized that the hyperghrelinemia observed in PWS is related to IGF-I or GH/IGF axis deficiency. DESIGN We investigated the densities of ghrelin-expressing cells (GECs), the amounts of ghrelin in gastric tissues, and ghrelin levels in plasma in 16 PWS patients and compared these results with those of 13 GHD patients and comparison groups (19 normal lean and 10 normal obese subjects). RESULTS In the gastric body and fundus, 2- to 3-fold increases in the numbers of GECs (P < 0.001) and in the amounts of ghrelin (P < 0.018) were noted in PWS patients vs. comparison groups, whereas GEC numbers in GHD patients were similar to those of the comparison group despite elevated fasting plasma ghrelin levels. In addition, IGF-I sd scores in PWS were not found to be correlated with GEC densities, the amounts of ghrelin expressed in gastric tissues, or plasma ghrelin levels. CONCLUSIONS Our results suggest that IGF-I or GH/IGF axis deficiency appears to be unrelated to observed GEC increases in the stomach of patients with PWS.
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Pagliardini S, Ren J, Wevrick R, Greer JJ. Developmental abnormalities of neuronal structure and function in prenatal mice lacking the prader-willi syndrome gene necdin. THE AMERICAN JOURNAL OF PATHOLOGY 2005; 167:175-91. [PMID: 15972963 PMCID: PMC1603432 DOI: 10.1016/s0002-9440(10)62964-1] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Necdin (Ndn) is one of a cluster of genes deleted in the neurodevelopmental disorder Prader-Willi syndrome (PWS). Ndntm2Stw mutant mice die shortly after birth because of abnormal respiratory rhythmogenesis generated by a key medullary nucleus, the pre-Bötzinger complex (preBötC). Here, we address two fundamental issues relevant to its pathogenesis. First, we performed a detailed anatomical study of the developing medulla to determine whether there were defects within the preBötC or synaptic inputs that regulate respiratory rhythmogenesis. Second, in vitro studies determined if the unstable respiratory rhythm in Ndntm2Stw mice could be normalized by neuromodulators. Anatomical defects in Ndntm2Stw mice included defasciculation and irregular projections of axonal tracts, aberrant neuronal migration, and a major defect in the cytoarchitecture of the cuneate/gracile nuclei, including dystrophic axons. Exogenous application of neuromodulators alleviated the long periods of slow respiratory rhythms and apnea, but some instability of rhythmogenesis persisted. We conclude that deficiencies in the neuromodulatory drive necessary for preBötC function contribute to respiratory dysfunction of Ndntm2Stw mice. These abnormalities are part of a more widespread deficit in neuronal migration and the extension, arborization, and fasciculation of axons during early stages of central nervous system development that may account for respiratory, sensory, motor, and behavioral problems associated with PWS.
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Shapira NA, Lessig MC, He AG, James GA, Driscoll DJ, Liu Y. Satiety dysfunction in Prader-Willi syndrome demonstrated by fMRI. J Neurol Neurosurg Psychiatry 2005; 76:260-2. [PMID: 15654046 PMCID: PMC1739487 DOI: 10.1136/jnnp.2004.039024] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The neurobiology relating to the insatiable appetite observed in Prader-Willi syndrome (PWS) has not been fully characterised. Two functional magnetic resonance imaging (fMRI) scans were performed on each of three adults with PWS. The scans were carried out pre- and post-treatment with the antiepileptic topiramate, which had little effect on body weight and appetite in these subjects. Subjects fasted overnight and drank a 75 g dextrose solution prior to fMRI scans for measurement of brain activation levels during/after glucose ingestion. Following glucose administration, there was a significant delay in activation at the hypothalamus and other brain regions associated with satiety compared with previous data on obese volunteers. These regions include the insula, ventromedial prefrontal cortex, and nucleus accumbens. Individuals with PWS showed a mean latency of 24 min while in a previous study obese volunteers had shown a latency of 15 min and lean volunteers a latency of 10 min in the hypothalamus. Our results provide evidence towards a satiety dysfunction in the central nervous system of PWS patients.
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Schepis C, Greco D, Siragusa M, Romano C. Piezogenic pedal papules during Prader-Willi syndrome. J Eur Acad Dermatol Venereol 2005; 19:136-7. [PMID: 15649213 DOI: 10.1111/j.1468-3083.2004.01048.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Boyd L, Brown MG, Kelson S, Lawce H, Shuttleworth S, Unsworth N, Magenis RE. Mosaicism of proximal 15q duplication/deletion resulting in Prader-Willi syndrome with normal methylation. Am J Med Genet A 2005; 138A:181-4. [PMID: 16100727 DOI: 10.1002/ajmg.a.30819] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Aretz S, Raff R, Woelfle J, Zerres K, Esser M, Propping P, Eggermann T. Maternal uniparental disomy 14 in a 15-year-old boy with normal karyotype and no evidence of precocious puberty. Am J Med Genet A 2005; 135:336-8. [PMID: 15887281 DOI: 10.1002/ajmg.a.30755] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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72
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Paik KH, Jin DK, Song SY, Lee JE, Ko SH, Song SM, Kim JS, Oh YJ, Kim SW, Lee SH, Kim SH, Kwon EK, Choe YH. Correlation between fasting plasma ghrelin levels and age, body mass index (BMI), BMI percentiles, and 24-hour plasma ghrelin profiles in Prader-Willi syndrome. J Clin Endocrinol Metab 2004; 89:3885-9. [PMID: 15292322 DOI: 10.1210/jc.2003-032137] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Ghrelin is a GH-releasing acylated peptide found in the stomach and a centrally acting food intake stimulator. Prader-Willi syndrome (PWS) is a genetic disorder characterized by a voracious appetite and increased fasting ghrelin levels. In this report we describe 24-h ghrelin profiles in PWS children (n = 5) and compare these with age, sex, and body mass index (BMI)-matched controls (n = 5). A 3- to 4-fold increase in ghrelin levels was found in PWS over a 24-h period, compared with controls (P < 0.001). Interestingly, there was a greater tendency for the up-regulation of ghrelin level in lean PWS than in obese PWS. To confirm this finding, we measured fasting ghrelin levels in 39 patients with PWS. Inverse correlations were found between plasma ghrelin levels and the following: age (r = -0.408, P = 0.005), BMI (r = -0.341, P = 0.017), percentage of the ideal weight for age (r = -0.382, P = 0.008), and BMI percentile (r = -0.311, P = 0.027). Our data show that there may be a suppressive (or up-regulating) controlling mechanism of ghrelin secretion in obese (or lean) PWS children. We hope that our data may further explain the mechanisms underlying the insatiable appetite and obesity characteristic of PWS.
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Goldstone AP, Thomas EL, Brynes AE, Castroman G, Edwards R, Ghatei MA, Frost G, Holland AJ, Grossman AB, Korbonits M, Bloom SR, Bell JD. Elevated fasting plasma ghrelin in prader-willi syndrome adults is not solely explained by their reduced visceral adiposity and insulin resistance. J Clin Endocrinol Metab 2004; 89:1718-26. [PMID: 15070936 DOI: 10.1210/jc.2003-031118] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Plasma ghrelin is elevated in Prader-Willi syndrome (PWS). This might contribute to obesity or GH deficiency in such patients. Visceral adiposity and insulin resistance are reduced in PWS, which might lead to hyperghrelinemia. We measured fasting plasma ghrelin in control female (n = 39), PWS female (n = 12), and PWS male (n = 6) adults. In controls and PWS, ghrelin was negatively correlated with visceral adiposity, fasting insulin, and homeostasis model insulin resistance index. There was no significant correlation with serum IGF-I in PWS. In stepwise linear regression, visceral adiposity (P < 0.02) had a stronger inverse correlation with ghrelin than sc fat depots in controls and PWS, possibly through hyperinsulinemia, as the correlations with insulin resistance were even stronger (P < 0.01). PWS females had significantly (P < 0.001) elevated ghrelin (mean +/- SD, 661 +/- 360 pg/ml), compared with both nonobese (363 +/- 163) and obese (191 +/- 66) controls. Ghrelin was increased 3.4- to 3.6-fold in PWS females adjusting for total adiposity, 3.2- to 3.4-fold adjusting for visceral adiposity, and 3.0-fold adjusting for insulin resistance. Fasting plasma glucagon-like peptide-1 was normal in PWS females. The hyperghrelinemia in PWS adults is therefore not solely explained by their reduced visceral adiposity and relative hypoinsulinemia. Its cause and consequences await further elucidation.
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Nazarenko S, Sazhenova E, Baumer A, Schinzel A. Segmental maternal heterodisomy of the proximal part of chromosome 15 in an infant with Prader–Willi syndrome. Eur J Hum Genet 2004; 12:411-4. [PMID: 14997184 DOI: 10.1038/sj.ejhg.5201168] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Uniparental disomy (UPD) 15, detected in patients with Prader-Willi (PWS) and Angelman syndromes, has to date always involved the entire chromosome 15. We report the first case of segmental maternal uniparental heterodisomy confined to a proximal part of chromosome 15 in a child with clinical features of PWS. This unusual finding can be explained by the rare combination of three consecutive events: a trisomy 15 zygote caused by a maternal meiosis I error, early postzygotic mitotic recombination between maternal and paternal chromatids, and, finally, trisomy rescue by the loss of the rearranged chromosome 15 containing the paternal 15q11-q13 segment.
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Bizzarri C, Rigamonti AE, Giannone G, Berardinelli R, Cella SG, Cappa M, Müller EE. Maintenance of a normal meal-induced decrease in plasma ghrelin levels in children with Prader-Willi syndrome. Horm Metab Res 2004; 36:164-9. [PMID: 15057669 DOI: 10.1055/s-2004-814340] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Ghrelin is a 28-amino acid peptide recently identified in the stomach as the endogenous ligand for the growth hormone secretagogue receptor (GHS-R1a). Ghrelin is a potent stimulator of GH secretion. It was recently shown that circulating ghrelin levels in humans rise shortly before and fall shortly after every meal, and that ghrelin administration increases voluntary food intake. The hypothesis that ghrelin hypersecretion might contribute to genetic obesity has never been investigated. In this context, Prader-Willi syndrome is the most common form of human syndromic obesity. As ghrelin affects appetite as well as GH secretion and both are abnormal in PWS, it has been surmised that these alterations might be due to ghrelin dysregulation. The aim of the study was to investigate whether ghrelin is suppressed by the meals differently in PWS children than in PWS adults. Overnight circulating fasting ghrelin levels and ghrelin levels 120 min after breakfast were assayed in 7 PWS children (10.2 +/- 1.7 yr), 7 subjects with morbid obesity (10.3 +/- 1.3 yr), and 5 normal controls (8.4 +/- 1.4 yr). Because of the data spread, no statistical difference was observed in fasting ghrelin levels between PWS and control children (p = NS); anyway, fasting ghrelin levels were significantly lower in obese children than in the other groups (p < 0.05 vs. control and PWS children). Ghrelin levels were slightly suppressed by the meal in control subjects (mean fasting ghrelin: 160.2 +/- 82 pg/ml; after the meal, 141.2 +/- 57 pg/ml, p = NS); the meal failed to suppress ghrelin levels in obese children (mean fasting ghrelin: 126.4 +/- 8.5 pg/ml; after the meal, 119.1 +/- 8.3 pg/ml, p = NS). Interestingly, the meal markedly suppressed ghrelin levels in PWS children (mean fasting ghrelin: 229.5 +/- 70.4 pg/ml; after the meal, 155.8 +/- 34.2 pg/ml, p < 0.01). In conclusion, since a lack of decrease in circulating ghrelin induced by the meal was previously reported in PWS adults, the finding of a meal-induced decrease in ghrelin levels in our population of young PWS would imply that the regulation of the ghrelin system involved in the orexigenic effects of the peptide is operative during childhood, although it progressively deteriorates and is absent in adulthood when hyperphagia and obesity progressively worsen.
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