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

Osteopetrosis is an inherited skeletal condition characterized by increased bone radiodensity. There are three clinical groups: infantile-malignant autosomal recessive, fatal within the first few years of life (in the absence of effective therapy); intermediate autosomal recessive, appears during the first decade of life but does not follow a malignant course; and autosomal dominant, with full-life expectancy but many orthopaedic problems. The infantile variant shows a myelophthisic anemia, granulocytopenia, and thrombocytopenia, and patients eventually die from infection or bleeding or both. Neurologic sequelae include cranial nerve compression (optic nerve, blindness; auditory nerve, deafness; facial nerve, paresis), hydrocephalus, convulsions, and mental retardation. Radiographs show uniform bone density without corticomedulary demarcation, broadened metaphyses, "bone within a bone" or endobone phenomena (tarsals, carpals, phalanges, vertebra, ilium), and thickened growth plates if there is superimposed rickets. Transverse pathologic fractures occur, often followed by massive periosteal bone formation. Computed tomographic scans, magnetic resonance imaging, and bone scans provide specific information. Iliac crest bone biopsy is valuable to quantitate osteoclast and marrow changes by light and electron microscopy. Medical treatments involve high-dose calcitriol to stimulate osteoclast differentiation and bone marrow transplantation to provide monocytic osteoclast precursors. Orthopaedic problems in the intermediate and autosomal dominant forms include increased fractures, coxa vara, long-bone bowing, hip and knee degenerative arthritis, and mandibular and long-bone osteomyelitis. Cranial nerve compression also occurs. Osteotomy, plating, intramedullary rodding, and joint arthroplasty can be done, but are difficult because of bone hardness.
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PMID:Osteopetrosis. Current clinical considerations. 835 40

Osteopetrosis is a rare hereditary bone disorder that presents in one of three forms: osteopetrosis tarda, osteopetrosis congenita and "marble bone" disease. Osteopetrosis tarda, the benign form, presents in adulthood, while the two more malignant variants, osteopetrosis congenita and marble bone disease, present in infancy and childhood, respectively. In all three forms, the main features are pathologic alteration of osteoclastic bone resorption and thickening of cortical and lamellar bones. Osteopetrosis tarda is usually discovered accidentally on routine radiographs and is often asymptomatic; however, patients may present because of related degenerative joint disease. Osteopetrosis congenita results in bone marrow failure and is almost always fatal. Marble bone disease causes short stature, cerebral calcification and mental retardation. Bone marrow transplant is the only chance for survival in patients with osteopetrosis congenita.
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PMID:Osteopetrosis. 953 12

Down Syndrome (DS) is the most common of the chromosomal disorders and manifests abnormalities in several organ systems. While mental retardation, skull and brain anomalies, and the development of Alzheimer-type neuropathological changes in patients greater than age 40 years are well recognized by neurologists and neuropathologists, less appreciated are the various cervical spine abnormalities that can occur. Widening of the anterior atlanto-odontoid distance (AAOD) and atlantooccipital instability occur in up to 21% and 63% of DS patients, respectively, but neurologic complaints are uncommon and rarely are severe enough to contribute to the patient's demise. We present a case of 49-year-old DS patient whose triplegia, subacute progressive respiratory failure, and death could be attributed to severe degenerative joint disease of the cervical spine with osteophyte formation and severe spinal canal stenosis. We provide the first detailed correlation study between pre-mortem magnetic resonance imaging (MRI) and extensive autoptic dissection in an adult DS patient with cervical spine abnormalities, as well as a review of the literature.
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PMID:Cervical spine abnormalities in Down Syndrome. 1050 34

Iodothyronine deiodinases represent a family of selenoproteins involved in peripheral and local homeostasis of thyroid hormone action. Deiodinases are expressed in multiple organs and thyroid hormone affects numerous biological systems, thus genetic variation in deiodinases may affect multiple clinical endpoints. Interest in clinical effects of genetic variation in deiodinases has clearly increased. We aimed to provide an overview for the role of deiodinase polymorphisms in human physiology and morbidity. In this systematic review, studies evaluating the relationship between deiodinase polymorphisms and clinical parameters in humans were eligible. No restrictions on publication date were imposed. The following databases were searched up to August 2013: Pubmed, EMBASE (OVID-version), Web of Science, COCHRANE Library, CINAHL (EbscoHOST-version), Academic Search Premier (EbscoHOST-version), and ScienceDirect. Deiodinase physiology at molecular and tissue level is described, and finally the role of these polymorphisms in pathophysiological conditions is reviewed. Deiodinase type 1 (D1) polymorphisms particularly show moderate-to-strong relationships with thyroid hormone parameters, IGF1 production, and risk for depression. D2 variants correlate with thyroid hormone levels, insulin resistance, bipolar mood disorder, psychological well-being, mental retardation, hypertension, and risk for osteoarthritis. D3 polymorphisms showed no relationship with inter-individual variation in serum thyroid hormone parameters. One D3 polymorphism was associated with risk for osteoarthritis. Genetic deiodinase profiles only explain a small proportion of inter-individual variations in serum thyroid hormone levels. Evidence suggests a role of genetic deiodinase variants in certain pathophysiological conditions. The value for determination of deiodinase polymorphism in clinical practice needs further investigation.
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PMID:Genetics in endocrinology: genetic variation in deiodinases: a systematic review of potential clinical effects in humans. 2487 78

Patients with mucopolysaccharidoses (MPS) have accumulation of glycosaminoglycans in multiple tissues which may cause coarse facial features, mental retardation, recurrent ear and nose infections, inguinal and umbilical hernias, hepatosplenomegaly, and skeletal deformities. Clinical features related to bone lesions may include marked short stature, cervical stenosis, pectus carinatum, small lungs, joint rigidity (but laxity for MPS IV), kyphoscoliosis, lumbar gibbus, and genu valgum. Patients with MPS are often wheelchair-bound and physical handicaps increase with age as a result of progressive skeletal dysplasia, abnormal joint mobility, and osteoarthritis, leading to 1) stenosis of the upper cervical region, 2) restrictive small lung, 3) hip dysplasia, 4) restriction of joint movement, and 5) surgical complications. Patients often need multiple orthopedic procedures including cervical decompression and fusion, carpal tunnel release, hip reconstruction and replacement, and femoral or tibial osteotomy through their lifetime. Current measures to intervene in bone disease progression are not perfect and palliative, and improved therapies are urgently required. Enzyme replacement therapy (ERT), hematopoietic stem cell transplantation (HSCT), and gene therapy are available or in development for some types of MPS. Delivery of sufficient enzyme to bone, especially avascular cartilage, to prevent or ameliorate the devastating skeletal dysplasias remains an unmet challenge. The use of an anti-inflammatory drug is also under clinical study. Therapies should start at a very early stage prior to irreversible bone lesion, and damage since the severity of skeletal dysplasia is associated with level of activity during daily life. This review illustrates a current overview of therapies and their impact for bone lesions in MPS including ERT, HSCT, gene therapy, and anti-inflammatory drugs.
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PMID:Therapies for the bone in mucopolysaccharidoses. 2553 51