Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two patients aged 17 and 25 years with Kearns syndrome are described. This condition is characterized by the triad of chronic progressive external ophthalmoplegia, pigmentary degeneration of of the retina and cardiac conduction defects. A review of the literature reveals frequent association with other symptoms, mainly cerebellar ataxia, neurosensory hearing loss, small stature, muscle weakness, mental retardation or dementia and endocrine disturbances. In skeletal and extraocular muscle biopsies, abnormalities of mitochondria, at present of unknown significance, have been found. CSF protein is almost always increased. The etiology of this multisystem disorder remains obscure. The 58 published cases have been sporadic, with no evidence of hereditary transmission. The prognosis seems mainly to depend on the progressive cardiac conduction defects, since several patients have already died in the second or third decade due to heart block. Patients with progressive external ophthalmoplegia should be investigated for Kearns syndrome. If appropriate, implantation of a cardiac pacemaker should be considered.
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PMID:[Kearns syndrome. Progressive external ophthalmoplegia, retinal pigment degeneration and heart conduction disorders]. 59 31

Twelve patients with histologically defined mitochondrial myopathy are described. There were 9 males and 3 females. The age of onset ranged from birth to 35 years with a median of 14 years. The most common clinical picture was that of ophthalmoplegia, ptosis and muscle weakness found in 10 patients. One presented with exercise intolerance due to muscular aches and pains, and the other besides his muscular weakness had mental retardation and an aggressive behavior. The clinical presentation and differential diagnosis of these patients are discussed.
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PMID:[Mitochondrial myopathy: report of 12 cases with histochemical study of the skeletal muscle]. 180 26

The Kearns-Sayre syndrome is identified by the triad of progressive external ophthalmoplegia, atypical pigmentary retinopathy, and conduction disturbances. In addition, clinical manifestations may include mental retardation, sensorineural deafness, cerebellar ataxia, and facial and peripheral muscle weakness. Morphologic alterations in skeletal muscle may be characterized by ragged-red fibers. Two patients with Kearns-Sayre syndrome underwent electrophysiological examination. The first patient had a first and second degree AV block (Mobitz type II), right bundle branch block, and left axis deviation. The His-bundle electrogram showed a prolonged HV interval as a hint at an intraventricular conduction delay. The signal-averaging technique and endocardial mapping revealed ventricular after-depolarizations. The second patient had an unsuspicious ECG, recurrent atrial tachycardias, normal atrial and ventricular conduction, and after-depolarizations in endocardial mapping. Two months later he showed a second degree AV block combined with clinical symptoms. Pacemakers were implanted in both patients. Beside disturbances of the conduction system in both patients signs of electrical instability of the myocardium were found. In this way the Kearns-Sayre syndrome may be seen as a form of cardiomyopathy.
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PMID:[Electrophysiologic findings in patients with Kearns-Sayre syndrome--report on 2 cases]. 240 85

A 19-year-old man with chronic progressive external ophthalmoplegia with deleted mitochondrial DNA was reported. Neurological examination revealed bilateral external ophthalmoplegia, hearing loss of sensorineural type, short stature, mental retardation, muscle atrophy and weakness in the proximal muscles. Lactate and pyruvate levels were elevated in both serum and cerebrospinal fluid (CSF). Protein concentration was slightly increased in CSF. Electromyogram showed myopathic changes on all the muscles examined. Ragged-red fibers were found in biopsied rectus femoris muscle, stained with modified Gomori trichrome. Scattered cytochrome c oxidase deficient fibers were encountered. The computed tomography of the brain showed mild cerebral and cerebellar atrophy without any abnormal calcification or hypo-lucency. Southern blot analysis of the mitochondrial DNA (mtDNA) extracted from the patient's muscle revealed mixed population of mtDNA, consisting of the normal one and partially deleted one. The size of the deletion was about 4.5-kilobase. The region included the sequences coding for at least four subunits of Complex I, one subunit of Complex IV, two subunits of Complex V and five tRNAs. There may be a "hot area" on the mitochondrial genome that is more prone to be deleted than other regions of mtDNA. Southern blot analysis is usefull for the diagnosis of KSS or CPEO.
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PMID:[Chronic progressive external ophthalmoplegia (CPEO) with deleted mitochondrial DNA]. 259 47

We report here two cases in a family with pleomorphic clinical features which include mitochondrial myopathy, encephalopathy, stroke-like episodes, episodic disturbances of consciousness and other multisystemic abnormalities. The other signs observed in multisystemic abnormalities were ophthalmoplegia, short stature, diabetes mellitus, diabetes insipidus, renal dysfunction, optic atrophy, retinal degeneration, impairment of hearing and mental retardation or deterioration. A symptomatological variation was observed in cases in the same family. It is suggested that these widely varying symptoms may be expressions caused by a common biochemical defect which involves different tissues in different individuals in the family. The syndromes observed in the present cases were compared with other possibly-related mitochondrial encephalomyopathies.
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PMID:Familial mitochondrial encephalomyopathy with stroke-like episodes and episodic disturbances of consciousness: a study of pedigree including three generations with multisystemic abnormalities. 362 95

Ten autopsy cases of Progressive Supranuclear Palsy (PSP) are reported. Age at onset ranged from 16 to 67 years and the duration of illness 3 to 24 years. The clinical features were aggressive mental retardation in 4 cases with early onset, paroxysmal dysequilibrium, ophthalmoplegia, rigidity and akinesia, pseudobulbar palsy and variable degrees of dementia. Neuropathology showed widespread neurofibrillary degeneration associated with system-bound neuronal loss and gliosis in subcortical areas, particularly affecting the subthalamic nucleus, substantia nigra, brainstem tegmentum and dentate nuclei, with no or little involvement of the cerebral cortex. The distribution of the lesions and the ultrastructure of the neurofibrillary tangles made of 15 nm straight filaments (seen in one case) in PSP are different from postencephalitic parkinsonism, Guam Parkinson-dementia complex and brainstem affection in (pre)senile dementia. Post-mortem biochemical analysis of two brains disclosed severe reduction of tyrosine hydroxylase, the key synthetic enzyme of the catecholamine pathway, not only in the nigrostriatal system as seen in Parkinson's disease, but in most areas of the brain-stem and limbic system. The implication and possible pathogenic and therapeutic significance of these biochemical findings are discussed. The etiology of PSP and its nosological position within the degenerative extrapyramidal disorders remain unknown.
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PMID:Progressive supranuclear palsy: clinico-pathological and biochemical studies. 610 28

We report on 4 boys (3 in one family) who have a remarkably constant syndrome of childhood-onset choreoathetosis with later spasticity, postnatal microcephaly, growth and mental retardation, apparent external ophthalmoplegia and varying degrees of deafness. The pedigrees are consistent with X-linked inheritance. The syndrome is compared and contrasted with others comprising basal ganglion dysfunction in childhood. It is concluded that clinically and genetically the condition is unique.
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PMID:A new X-linked syndrome comprising progressive basal ganglion dysfunction, mental and growth retardation, external ophthalmoplegia, postnatal microcephaly and deafness. 653 52

Osteopathia striata with cranial sclerosis (OS-CS) is a specific bone dysplasia manifested by hypertelorism, flat nasal bridge, frontal bossing, large head, hypoplastic maxilla, palate anomalies, chronic otitis media, hearing deficits, nasal obstruction, and neurological changes of deafness, facial palsy, ophthalmoplegia, and mental retardation. We will review the clinical and radiologic findings in a new patient from birth to 20 years; this is believed to be the thirty-fifth patient reported. OS-CS is 2.5 times more common in females and occurs as an autosomal dominant condition or a sporadic dominant mutation with patients presenting for evaluation from the newborn period to the fifth decade. Skeletal abnormalities are distinctive including sclerosis of the skull base and calvarium, linear striated densities in the long bones and pelvis, and poor development of the mastoid and sinus air cells. Radionuclide bone scans with SPECT indicated in our patient increased bone turnover which was supported by biochemical findings of increased pyridinoline excretion. The major complications are due to constriction of essential foramina at the skull base. The condition is not life-threatening but can produce disability.
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PMID:Osteopathia striata with cranial sclerosis. 800

Fourteen patients (10 boys, 4 girls) aged from 4 months to 14 years old were diagnosed with mitochondrial disease based on the clinical manifestations together with abnormal muscle mitochondrial morphologies. Their clinical diagnoses included Leigh syndrome, three; Menkes' syndrome, three; Kearns-Sayre syndrome, two; myoclonic epilepsy with ragged fibres, one; and infant-onset progressive myoclonic epilepsy, one; fatal infantile mitochondrial myopathy, one; fatty acid oxidation defect, two; and myopathy with cardiopathy, one. Organs involved other than muscles included central nervous system, ten; heart, six; eye, two; liver, two; and kidney, two. Clinical manifestations varied to include hypotonia, seizures, myoclonus, mental retardation, nystagmus, ataxia, ptosis, ophthalmoplegia, retinal degeneration, muscle atrophy, spasticity etc. Nine had an abnormal rise in lactate after glucose loading. Ragged-red fibres were found in four patients. Abnormal mitochondrial morphology included abnormal accumulation, abnormal cristae pattern of tubular, concentric, or parallel form, some contained osmiophilic inclusion bodies. One patient of Leigh syndrome had had brain necropsy which showed intramyelin splitting of myelinated axons.
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PMID:Clinical manifestation of mitochondrial diseases in children. 821 54

We examined a large family in which an X-linked recessive congenital ataxia manifested in 7 males from three generations. The affected boys first exhibited a marked delay of early developmental motor milestones. A neurological syndrome became evident by 5 to 7 years of age and included cerebellar ataxia, dysarthria, and external ophthalmoplegia; there were no symptoms of mental retardation, spastic paraparesis, or sensory loss. Neuroimaging studies revealed hypoplasia of cerebellar hemispheres and vermis. The disease showed no progression beyond early childhood. The unique heredity and clinical features clearly distinguish this new entity from a variety of previously described familial ataxias. Pairwise linkage analysis and haplotype reconstruction allowed us to map the gene responsible for this disorder to a 38-cM interval on chromosome Xp11.21-q24 flanked by the loci DXS991 and DXS1001. Upon multipoint linkage analysis, the disease gene was determined to be located most likely in the proximal part of chromosome Xq, with the maximal lod score of 4.66 at the locus DXS1059 (Xq23). This is the first example of the genetic mapping of a pure congenital cerebellar hypoplasia syndrome.
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PMID:X-linked nonprogressive congenital cerebellar hypoplasia: clinical description and mapping to chromosome Xq. 868 95


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