Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0917816 (mental retardation)
 15,867 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Several "progeroid" syndromes have now been identified. The De Barsy syndrome is an autosomal recessive syndrome of dwarfism, mental deficiency, an "aged" appearance at birth, abnormal elastic fibers on skin biopsy, and lax skin, large helices, eye abnormalities, lax joints, hypotonia, and athetoid posturing. We report one case and review 11 cases from the literature. To understand the abnormal appearance of the elastic fibers on biopsy, we performed elastin gene expression studies on fibroblasts cultured from our patient's skin. Molecular hybridization studies revealed reduced elastin mRNA steady-state levels as compared with age matched control individuals. Assuming normal rates of mRNA translation, reduced elastin synthesis would occur. Diminished dermal elastin content could explain the altered cutaneous elasticity, decreased elastic fibers in the skin, and many clinical manifestations of individuals with this condition.
 ...
PMID:De Barsy syndrome: report of a case, literature review, and elastin gene expression studies of the skin. 130 62

Fragile-X syndrome is one of the most common inherited forms of mental retardation. An associated connective-tissue disorder involving elastin accounts for the most frequent musculoskeletal manifestations, which include severe flexible flat feet, excessive laxity of the joints, and scoliosis. At our institution, seventy-five (50 per cent) of the 150 male patients who had fragile-X syndrome had flat feet, eighty-five (57 per cent) had excessive laxity of the joints, and ten had scoliosis. Twenty-nine of the patients who had flat feet had been evaluated or treated, or both, by an orthopaedic surgeon before the diagnosis of fragile-X syndrome had been made. Only one of these patients had been referred for developmental and genetic evaluation, which suggests that the orthopaedic community is not familiar with this syndrome. The orthopaedist should consider the diagnosis of fragile-X syndrome in the evaluation of a mentally retarded boy or man who has a family history of mental retardation. The presence of flat feet and excessive laxity of the joints, associated with the characteristic facies, macro-orchidism, and behavior, justifies a referral for developmental and genetic evaluation. Early diagnosis is important for several reasons, including genetic counseling for the family, more efficacious medical treatment, and specialized education.
 ...
PMID:Orthopaedic aspects of fragile-X syndrome. 219 34

Williams syndrome (WS) is generally characterized by mental deficiency, gregarious personality, dysmorphic facies, supravalvular aortic stenosis, and idiopathic infantile hypercalcemia. Patients with WS show allelic loss of elastin (ELN), exhibiting a submicroscopic deletion, at 7q11.23, detectable by FISH. Hemizygosity is likely the cause of vascular abnormalities in WS patients. A series of 235 patients was studied, and molecular cytogenetic deletions were seen in 96% of patients with classic WS. Patients included 195 solicited through the Williams Syndrome Association (WSA), plus 40 clinical cytogenetics cases referred by primary-care physicians. Photographs and medical records of most WSA subjects were reviewed, and patients were identified as "classic" (n = 114) or "uncertain" (n = 39). An additional 42 WSA patients were evaluated without clinical information. FISH was performed with biotinylated ELN cosmids on metaphase cells from immortalized lymphoblastoid lines from WSA patients and after high-resolution banding analysis on clinical referral patients. An alpha-satellite probe for chromosome 7 was included in hybridizations, as an internal control. Ninety-six percent of the patients with classic WS showed a deletion in one ELN allele; four of these did not show a deletion. Of the uncertain WS patients, only 3 of 39 showed a deletion. Of the 42 who were not classified phenotypically, because of lack of clinical information, 25 patients (60%) showed a deletion. Thirty-eight percent (15/40) of clinical cytogenetics cases showed an ELN deletion and no cytogenetic deletion by banded analysis. These results support the usefulness of FISH for the detection of elastin deletions as an initial diagnostic assay for WS.
 ...
PMID:Strong correlation of elastin deletions, detected by FISH, with Williams syndrome: evaluation of 235 patients. 761 Dec 95

Williams syndrome (WS) is a multisystem developmental disorder caused by the deletion of contiguous genes at 7q11.23. Hemizygosity of the elastin (ELN) gene can account for the vascular and connective tissue abnormalities observed in WS patients, but the genes that contribute to features such as infantile hypercalcemia, dysmorphic facies, and mental retardation remain to be identified. In addition, the size of the genomic interval commonly deleted in WS patients has not been established. In this study we report the characterization of a 500-kb region that was determined to be deleted in our collection of WS patients. A detailed physical map consisting of cosmid, P1 artificial chromosomes, and yeast artificial chromosomes was constructed and used for gene isolation experiments. Using the techniques of direct cDNA selection and genomic DNA sequencing, three known genes (ELN, LIMK1, and RFC2), a novel gene (WSCR1) with homology to RNA-binding proteins, a gene with homology to restin, and four other putative transcription units were identified. LIMK1 is a protein kinase with two repeats of the LIM/double zinc finger motif, and it is highly expressed in brain. RFC2 is the 40-kDa ATP-binding subunit of replication factor C, which is known to play a role in the elongation of DNA catalyzed by DNA polymerase delta and epsilon. LIMK1 and WSCR1 may be particularly relevant when explaining cognitive defects observed in WS patients.
 ...
PMID:Identification of genes from a 500-kb region at 7q11.23 that is commonly deleted in Williams syndrome patients. 881 60

Clinical and pathological observations of a 6-month-old-boy with Costello syndrome are reported. The main clinical findings were loose skin of the neck, hands, and feet, deep palmar and plantar creases, typical "coarse" face with thick lips and macroglossia, relative macrocephaly, mental retardation, short stature, arrhythmia, large size for gestational age, and poor feeding. At age 6 months he died of rhabdomyolysis. The major pathological findings were fine, disrupted, and loosely-constructed elastic fibers in the skin, tongue, pharynx, larynx, and upper esophagus, but not in the bronchi, alveoli, aorta, or coronary arteries. Hyperplasia of collagen fibers in the skin, hyperplasia of the mucous glands in the bronchus, narrowing of the pulmonary artery, degeneration of the atrial conduction system, calcification and ballooning of skeletal muscle fibers with infiltration of macrophages, and myoglobin depositions in the collecting ducts in the kidney were also observed. The degeneration of elastic fibers was confirmed in the skin of a second Costello syndrome patient. Expression of elastin mRNA in the patient's fibroblasts was normal in size and amount. Given that elastic fiber degeneration was observed in the tissues with clinical symptoms, we speculate that a defect of elastic fibers, possibly relating to alternative splicing in the elastin gene or to defects in elastin microfibrils, might be involved in the pathogenesis of Costello syndrome.
 ...
PMID:Elastic fiber degeneration in Costello syndrome. 883 40

Williams syndrome (WS) is characterized by distinct facial changes, growth deficiency, mental retardation, and congenital heart defect (particularly supravalvular aortic stenosis), associated at times with infantile hypercalcemia. Molecular genetic studies have indicated that hemizygosity at the elastin locus (7q11.23) causes WS. The purpose of this study was to confirm that this regional deletion, involving the elastin locus, is the cause of WS in Japan, and to clarify the correlation between the phenotype and the elastin locus. Thirty-two patients with WS and thirty of their relatives were examined by fluorescent in situ hybridization (FISH), using the WS chromosome region (WSCR) probe. All patients had cardiovascular disease (100%), 30 had typical WS facial changes (94%), 31 had mental retardation or developmental delay (97%), 16 were small-for-date at birth (50%), 14 had short stature (44%), and 13 had dental anomalies (41%). No relatives showed any manifestation of WS. Hemizygosity for a region of 7q11.23, involving the elastin locus, was found in all WS patients, but was not found in the 30 relatives.
 ...
PMID:Molecular cytogenetic diagnosis of Williams syndrome. 886 24

We report an unusual case with mental retardation, short stature, sparse scalp hair, prominence of scalp veins, atrophy of subcutaneous fat, pterygia of the neck and loose skin. The patient excreted greater amounts of low-sulphated chondroitin sulphate (LSC) in the urine than age-matched controls. The pattern of glycosaminoglycan in serum and its synthesis by the patient fibroblasts were normal. Collagen, elastin and decorin mRNA levels in the patient fibroblasts were also unaltered. These results suggest that this patient seems to be different from Lowe's syndrome and decorin-deficient progeroid. An abnormal LSC metabolism may be partially responsible for the pathology of these syndromes.
 ...
PMID:Overexcretion of low-sulphated chondroitin sulphate in the urine of the patient resembling progeroid. 940 87

Williams syndrome (WS) is a neurodevelopmental disorder with a variable phenotype. Molecular genetic studies have indicated that hemizygosity at the elastin locus (ELN) may account for the cardiac abnormalities seen in WS, but that mental retardation and hypercalcemia are likely caused by other genes flanking ELN. In this study, we defined the minimal critical deletion region in 63 patients using 10 microsatellite markers and 5 fluorescence in situ hybridization (FISH) probes on chromosome 7q, flanking ELN. The haplotype analyses showed the deleted cases to have deletions of consistent size, as did the FISH analyses using genomic probes for the known ends of the commonly deleted region defined by the satellite markers. In all informative cases deleted at ELN, the deletion extends from D7S489U to D7S1870. The genetic distance between these two markers is about 2 cM. Of the 51 informative patients with deletions, 29 were maternal and 22 were paternal in origin. There was no evidence for effects on stature by examining gender, ethnicity, cardiac status, or parental origin of the deletion. Heteroduplex analysis for LIMK1, a candidate gene previously implicated in the WS phenotype, did not show any mutations in our WS patients not deleted for ELN. LIMK1 deletions were found in all elastin-deletion cases who had WS. One case, who has isolated, supravalvular aortic stenosis and an elastin deletion, was not deleted for LIMK1. It remains to be determined if haploinsufficiency of LIMK1 is responsible in part for the WS phenotype or is simply deleted due to its close proximity to the elastin locus.
 ...
PMID:Delineation of the common critical region in Williams syndrome and clinical correlation of growth, heart defects, ethnicity, and parental origin. 963 30

Williams syndrome (WS) is a contiguous gene deletion disorder caused by haploinsufficiency of genes at 7q11.23. We have shown that hemizygosity of elastin is responsible for one feature of WS, supravalvular aortic stenosis (SVAS). We have also implicated LIM-kinase 1 hemizygosity as a contributing factor to impaired visual-spatial constructive cognition in WS. However, the common WS deletion region has not been completely characterized, and genes for additional features of WS, including mental retardation, infantile hypercalcemia, and unique personality profile, are yet to be discovered. Here, we present a physical map encompassing 1.5 Mb DNA that is commonly deleted in individuals with WS. Fluorescence in situ hybridization analysis of 200 WS individuals shows that WS individuals have the consistent deletion interval. In addition, we identify three novel genes from the common deletion region: WS-betaTRP, WS-bHLH, and BCL7B. WS-betaTRP has four putative beta-transducin (WD40) repeats, and WS-bHLH is a novel basic helix-loop-helix leucine zipper (bHLHZip) gene. BCL7B belongs to a novel family of highly conserved genes. We describe the expression profile and genomic structure for each of these genes. Hemizygous deletion of one or more of these genes may contribute to developmental defects in WS.
 ...
PMID:Complete physical map of the common deletion region in Williams syndrome and identification and characterization of three novel genes. 986 Mar 2

Williams-Beuren syndrome (WBS) is a rare neurodevelopmental disorder, characterized by distinct facial changes, growth deficiency, mental retardation, supravalvular aortic stenosis (SVAS)/peripheral pulmonary stenosis, and associated at times with infantile hypercalcemia. A pilot study has been carried out to assess the reliability of the detection of hemizygosity at the elastin locus by fluorescence in situ hybridization (FISH) analysis as a diagnostic test in both classical and atypical WBS. Eight subjects with classical WBS and four others in whom a diagnosis could not be confirmed on clinical criteria alone were enrolled. In the classical WBS group, five (5/8) had a visible interstitial 7q11.22-11.23 deletion detected by high-resolution banding, and all (8/8) had a submicroscopic deletion of the elastin locus on chromosome 7 by FISH analysis. In the atypical WBS group, only one (1/4) had elastin deletion. The other three, with isolated SVAS, had normal development and minimal signs of WBS. Furthermore, the patients with microscopic 7q11.22-11.23 deletion have more associated features of WBS than those without visible interstitial deletions by high-resolution banding. These results, therefore, emphasize the importance of a combined high-resolution and molecular cytogenetic (i.e., FISH) approach to diagnosis and suggest that the degree to which microscopic/submicroscopic deletions of chromosome 7 extending in beyond the elastin locus may explain some of the phenotypical variability found in WBS.
 ...
PMID:FISH analysis in both classical and atypical cases of Williams-Beuren syndrome. 992 15


1 2 Next >>