Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020505 (hyperphagia)
6,116 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The association of obesity, phenotypic abnormalities and mental retardation characterizes syndromic obesity. Its most common form is the Prader-Willi syndrome (PWS-- neonatal hypotonia, poor sucking, delayed psychomotor development, hyperphagia, severe obesity, short stature, small hands and feet, hypogonadism, mild to moderate mental retardation and behavioral disorders). A PWS-like phenotype has been described in patients with chromosome abnormalities involving the chromosome region 6q16.2 that includes the SIM1 gene. Herein we report cytogenetic and gene studies including a screening for the SIM1 gene deletion, performed on 87 patients with PWS-like phenotype, and describe the fifth case of syndromic obesity with an interstitial deletion of the chromosome segment 6q16-q21 and suggest that mutational analysis and further studies of the parental origin of chromosome alterations of 6q16.2 in patients with and without PWS-like phenotype are needed to evaluate possible imprinting effects of SIM1 gene and establish the contribution that alterations in this gene makes to the etiology of syndromic and non-syndromic obesity.
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PMID:A new case of interstitial 6q16.2 deletion in a patient with Prader-Willi-like phenotype and investigation of SIM1 gene deletion in 87 patients with syndromic obesity. 1682 51

Prader-Willi syndrome is a neurodevelopmental disorder that is characterized by infantile hypotonia, feeding difficulties, hypogonadism, mental deficiency, hyperphagia (leading to obesity in early childhood), learning problems, and behavioral difficulties. A paternal 15q11-q13 deletion is found in approximately 70% of patients with Prader-Willi syndrome, approximately 25% have uniparental maternal disomy 15, and the remaining 2% to 5% have imprinting defects. The proximal deletion breakpoint in the 15q11-q13 region occurs at 1 of 2 sites located within either of 2 large duplicons allowing for the identification of 2 deletion subgroups. The larger, type I (TI) deletion involves breakpoint 1, which is close to the centromere, whereas the smaller, type II (TII) deletion involves breakpoint 2, located approximately 500 kilobases distal to breakpoint 1. Breakpoint 3 is located at the distal end of the 15q11-q13 region and common to both typical deletion subgroups. Analyses of the genetic subtypes of Prader-Willi syndrome to date have primarily compared individuals with typical deletion and uniparental maternal disomy 15 without grouping the individuals with a deletion into TI or TII. Distinct differences have been reported between individuals with Prader-Willi syndrome resulting from deletion compared with uniparental maternal disomy 15 in physical, cognitive, and behavioral parameters. We previously presented the first assessment of clinical differences in individuals with Prader-Willi syndrome categorized as having type I or II deletions. Adaptive behavior, obsessive-compulsive behaviors, reading, math, and visual-motor integration assessments were generally poorer in individuals with Prader-Willi syndrome and the TI deletion compared with subjects with Prader-Willi syndrome with the TII deletion or uniparental maternal disomy 15. Four genes (NIPA1, NIPA2, CYFIP1, and GCP5) have been identified in the chromosomal region between breakpoints 1 and 2 and are implicated in compulsive behavior and lower intellectual ability observed in individuals with Prader-Willi syndrome with TI versus TII deletions. We quantified messenger-RNA levels of these 4 genes in actively growing lymphoblastoid cells derived from 8 subjects with Prader-Willi syndrome with the TI deletion (4 males, 4 females; mean: age 25.2 +/- 8.9 years) and 9 with the TII deletion (3 males, 6 females; mean age: 19.5 +/- 5.8 years). Messenger-RNA levels were correlated with validated psychological and behavioral scales administered by trained psychologists blinded to genotype status. Messenger RNA from NIPA1, NIPA2, CYFIP1, and GCP5 was reduced but detectable in the subjects with Prader-Willi syndrome with the TI deletion, supporting biallelic expression. For the most part, messenger-RNA values were positively correlated with assessment parameters, indicating a direct relationship between messenger-RNA levels and better assessment scores, with the highest correlation for NIPA2. The coefficient of determination indicated the quantity of messenger RNA of the 4 genes explained from 24% to 99% of the variation of the behavioral and academic parameters measured. By comparison, the coefficient of determination for deletion type alone explained 5% to 50% of the variation in the assessed parameters. Understanding the influence of gene expression on behavioral and cognitive characteristics in humans is in the early stage of research development. Additional research is needed to identify the function of these genes and their interaction with gene networks to clarify the potential role they play in central nervous system development and function.
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PMID:Expression of 4 genes between chromosome 15 breakpoints 1 and 2 and behavioral outcomes in Prader-Willi syndrome. 1698 6

Prader-Willi syndrome (PWS) is a genetically determined neurodevelopmental disorder characterized by mental retardation and distinct physical, behavioral, and psychiatric features. Based on parents' questionnaires, we examined the prevalence of behavioral and psychiatric disorders of 165 persons with PWS aged 2-31 years in Japan. The data were analyzed comparing four different age groups with PWS: group 1, 2-5 years (n=34); group 2, 6-11 years (n=57); group 3, 12-17 years (n=45); and group 4, 18-31 years (n=29). Further, we compared the results of our PWS group 4 with those of 42 age-, gender-, and intelligence level-matched intellectual disability (ID) individuals without PWS. Our results showed that repetitive speech and stubbornness were prominent from early childhood and other behavioral problems such as hyperphagia, stealing food, temper tantrums, lying, and emotional lability tended to be more frequent with age among persons with PWS. Moreover, young adults with PWS have significantly higher rates of behavioral and psychiatric disorders than IDs without PWS, such as stubbornness, hyperphagia, temper tantrums, self-injurious behavior (skin picking), hypersomnia, inactivity, and delusion. Degree of obesity was not necessarily related to behavioral and psychiatric features associated with PWS. Our findings revealed that persons with PWS are more vulnerable to behavioral and psychiatric disorders particularly in young adulthood compared to those with ID from other etiologies in Japan.
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PMID:Behavioral and psychiatric disorders in Prader-Willi syndrome: a population study in Japan. 1731 21

Smith-Magenis syndrome (SMS) is a multisystem disorder characterized by developmental delay and mental retardation, a distinctive behavioral phenotype, and sleep disturbance. We undertook a comprehensive meta-analysis to identify genotype-phenotype relationships to further understand the clinical variability and genetic factors involved in SMS. Clinical and molecular information on 105 patients with SMS was obtained through research protocols and a review of the literature and analyzed using Fisher's exact test with two-tailed p values. Several differences in these groups of patients were identified based on genotype and gender. Patients with RAI1 mutation were more likely to exhibit overeating, obesity, polyembolokoilamania, self-hugging, muscle cramping, and dry skin and less likely to have short stature, hearing loss, frequent ear infections, and heart defects when compared with patients with deletion, while a subset of small deletion cases with deletions spanning from TNFRSF13B to MFAP4 was less likely to exhibit brachycephaly, dental anomalies, iris abnormalities, head-banging, and hyperactivity. Significant differences between genders were also identified, with females more likely to have myopia, eating/appetite problems, cold hands and feet, and frustration with communication when compared with males. These results confirm previous findings and identify new genotype-phenotype associations including differences in the frequency of short stature, hearing loss, ear infections, obesity, overeating, heart defects, self-injury, self-hugging, dry skin, seizures, and hyperactivity among others based on genotype. Additional studies are required to further explore the relationships between genotype and phenotype and any potential discrepancies in health care and parental attitudes toward males and females with SMS.
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PMID:Gender, genotype, and phenotype differences in Smith-Magenis syndrome: a meta-analysis of 105 cases. 1753 3

Prader-Willi Syndrome (PWS) is a multisystemic genetic disease characterized by hypotonia, mental retardation, characteristic facial appearance, hyperphagia, and compulsive eating due to hypothalamic dysfunction. PWS is caused by loss of function of genes located in chromosome 15q11-q13, an area subject to genomic imprinting. Obesity is a major cause of increased morbidity and mortality among patients with PWS. The objective of this study was to analyze the therapeutic options available for the treatment of the obesity in PWS including pharmacological and surgical strategies.
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PMID:[Therapeutical approach of obesity in Prader-Willi Syndrome]. 1793 57

Prader Willi Syndrome (PWS) is characterized by typical appearance, obesity, short stature, hypothalamic hypogonadism, cryptorchidism, hypotonia, behavioural abnormalities and mental retardation. It is considered as a continuous genes syndrome with different genotypes: microdeletion of the region 15q11-q13 with paternal imprinting; maternal uniparental disomy (UPD) of chromosome 15; chromosomal rearrangement. Clinical manifestations evolve with age from newborn (hypotonia, poor sucking, hypoplastic external genitalia) to childhood (delay in psychomotor development, hyperphagia, obesity, acromicria and craniofacial dysmorphisms). We present five newborns who received an early diagnosis, based on clinical presentation. The early treatment and follow-up can in fact improve the natural evolution of the syndrome in order to prevent respiratory tract diseases and obesity, and to improve growth.
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PMID:Neonatal presentation of Prader Willi sindrome. Personal records. 1797 92

Prader-Willi syndrome (PWS) is characterized by neonatal hypotonia, hyperphagia, childhood obesity at an early age, short stature, varying degrees of mental deficiency, and hypogonadism. In PWS, puberty is usually delayed and fails to complete, with most females never having regular menstrual cycles. We report a female patient with uniparental disomy, who experienced precocious puberty with menarche at age 8 years. The patient was treated with luteinizing hormone releasing hormone (LHRH) analog, which suppressed pubertal development. From our search of the literature this is the first application of LHRH analog to a female PWS patient for precocious puberty. Use of LHRH analog along with recombinant human growth hormone (rhGH) permitted stature closer to target height. The clinical course of this patient with PWS underscores the need for individualized treatment.
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PMID:Treatment of precocious puberty in a female with Prader-Willi syndrome. 1865 33

Monosomy 1p36 is the most common subtelomeric microdeletion syndrome with an incidence rate estimated to be 1 in 5000 births. A hypothesis of a similarity between patients with 1p36 deletion and those with Prader-Willi syndrome and the existence of two different phenotypes for 1p36 microdeletion has been suggested. The main objective of the present study was to determine the existence of 1p36 microdeletion in a sample of patients with mental retardation, obesity and hyperphagia who tested negative by the methylation test for Prader-Willi syndrome. Sixteen patients (7 females, 9 males), 16-26 years old, were evaluated with high-resolution cytogenetic analysis at 550-850 band levels and with 11 polymorphic microsatellite markers located in the 1p36 region. All patients had normal cytogenetic and molecular results. The results obtained by high-resolution cytogenetic methodology were confirmed by the molecular analyses. We did not detect a 1p36 microdeletion in 16 subjects with the Prader-Willi-like phenotype, which reinforces that no correlation seems to exist between Prader-Willi-like phenotype and the 1p36 microdeletion syndrome.
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PMID:Lack of evidence for monosomy 1p36 in patients with Prader-Willi-like phenotype. 1879 1

Prader-Willi syndrome (PWS) is a complex, genetic, multisystem disorder. Its major clinical features include neonatal hypotonia and failure to thrive, mental retardation, hypogonadism, short hands and feet, hyperphagia-caused obesity, and characteristic appearance. The genetic basis of PWS is also complex. It is caused by the absence of expression of the active paternal genes such as the SNRPN, NDN, and possibly others in the PWS critical region on 15q11-13. PWS is in effect a contiguous gene syndrome resulting from deletion of the paternal copies of the imprinted. Consensus in clinical diagnostic criteria was established in 1993. However, identifying relevant patients for tests remains a challenge for most practitioners, as many features of the disorder are nonspecific, and others can be subtle or evolved over time. Consequently, molecular genetic tests can be used to diagnose PWS accurately, allowing early diagnosis of the syndrome. High resolution G-banding, high resolution cytogenetic methylation-specific PCR (MS-PCR), and fluorescence in situ hybridization (FISH) are routinely used to diagnose PWS. In this study, four Chinese patients, with typical PWS features, were detected by MS-PCR and FISH. Three were cytogenetically normal, but lacked paternal expression of proximal chromosome 15q because of maternal uniparental disomy (UPD). The other one, however, demonstrated an unbalanced de novo translocation 46, XX, t (7; 15).
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PMID:Clinical and genetic analysis for four Chinese families with Prader-Willi syndrome. 1942 99

Obesity is a highly heritable and genetically heterogeneous disorder. Here we investigated the contribution of copy number variation to obesity in 300 Caucasian patients with severe early-onset obesity, 143 of whom also had developmental delay. Large (>500 kilobases), rare (<1%) deletions were significantly enriched in patients compared to 7,366 controls (P < 0.001). We identified several rare copy number variants that were recurrent in patients but absent or at much lower prevalence in controls. We identified five patients with overlapping deletions on chromosome 16p11.2 that were found in 2 out of 7,366 controls (P < 5 x 10(-5)). In three patients the deletion co-segregated with severe obesity. Two patients harboured a larger de novo 16p11.2 deletion, extending through a 593-kilobase region previously associated with autism and mental retardation; both of these patients had mild developmental delay in addition to severe obesity. In an independent sample of 1,062 patients with severe obesity alone, the smaller 16p11.2 deletion was found in an additional two patients. All 16p11.2 deletions encompass several genes but include SH2B1, which is known to be involved in leptin and insulin signalling. Deletion carriers exhibited hyperphagia and severe insulin resistance disproportionate for the degree of obesity. We show that copy number variation contributes significantly to the genetic architecture of human obesity.
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PMID:Large, rare chromosomal deletions associated with severe early-onset obesity. 2088 Jan 23


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