Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026827 (hypotonia)
 5,860 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A male patient with profound mental retardation, athetosis, nystagmus, and severe congenital hypotonia (Duchenne muscular dystrophy [DMD]) was previously shown to carry a pericentric inversion of the X chromosome, 46,Y,inv(X)(p21.2q22.2). His mother carried this inversion on one X allele. The patient's condition was originally misdiagnosed as cerebral palsy, and only later was it diagnosed as DMD. Because the DMD gene is located at Xp21.2, which is one breakpoint of the inv(X), and because its defects are rarely associated with severe mental retardation, the other clinical features of this patient were deemed likely to be associated with the opposite breakpoint at Xq22. Our precise molecular-cytogenetic characterization of both breakpoints revealed three catastrophic genetic events that had probably influenced neuromuscular and cognitive development: deletion of part of the DMD gene at Xp21.2, duplication of the human proteolipid protein gene (PLP) at Xq22.2, and disruption of a novel gene. The latter sequence, showing a high degree of homology to the Sec4 gene of yeast, encoded a putative small guanine-protein, Ras-like GTPase that we have termed "RLGP." Immunocytochemistry located RLGP at mitochondria. We speculate that disruption of RLGP was responsible for the patient's profound mental retardation.
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PMID:The Xq22 inversion breakpoint interrupted a novel Ras-like GTPase gene in a patient with Duchenne muscular dystrophy and profound mental retardation. 1214 44

Selected spastic patients with cerebral palsy can be helped by peripheral reconstructive surgery, of the upper limb. Although surgery cannot make a limb that was functionally poor into a perfect one, it can greatly improve the preoperative condition. Most poor surgical results are caused by incorrect selection of patients or poor execution of surgical procedures. The worst mistake is to perform soft tissue procedures--tendinous release or tendinous transfers--on a patient with pure athetosis. The results in these cases are unpredictable and often fail. The same concept is applied to rigidity, hypotonia, dystonia, and ataxia. The surgical program is organized according to the type and severity of the deformity (clinical groups). The goals are to correct the deformities and to improve the muscular balance of the hand in one surgical stage. It must be remembered that spastic muscle cannot be used for tendon transfer with the same efficiency as in patients with a flaccid paralysis. Results were satisfactory in 92% of cases of groups I and II. If group III is included, the percentage of satisfactory results reduces significantly.
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PMID:Surgical management of the hand in infantile spastic hemiplegia. 1459 53

The aim of this study was to determine the effectiveness of an intraoral appliance, the Innsbruck Sensorimotor Activator and Regulator (ISMAR), in improving drooling and eating skills in a group of children with cerebral palsy, and to determine which factors might indicate good candidates for this type of treatment. Eighteen children (13 males, five females; mean age 7 years 10 months, range 4 to 13 years) were selected. Measures of drooling and feeding skills were taken at baseline, at the completion of a 6-month control phase, and at two more 6-monthly time points after the ISMAR was fitted. Children varied greatly in both the length of time taken to tolerate wearing the ISMAR and duration for which the appliance was worn. Only six children (four females, two males) completed the full study. Their motor disabilities were athetosis (n=3), spastic quadriplegia (n=2), and hypotonia (n=1); four of the six children used a wheelchair for locomotion. None had epilepsy and none had greater than mild cognitive impairment. For these children drooling severity scores and eating and drinking skills improved significantly over the treatment period in comparison with the control phase. We conclude that the ISMAR remains a valid option in improving drooling in children and merits further study.
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PMID:Effectiveness of the Innsbruck Sensorimotor Activator and Regulator in improving saliva control in children with cerebral palsy. 1497 46

Twinkle is a mitochondrial replicative helicase, the mutations of which have been associated with autosomal dominant progressive external ophthalmoplegia (adPEO), and recessively inherited infantile onset spinocerebellar ataxia (IOSCA). We report here a new phenotype in two siblings with compound heterozygous Twinkle mutations (A318T and Y508C), characterized by severe early onset encephalopathy and signs of liver involvement. The clinical manifestations included hypotonia, athetosis, sensory neuropathy, ataxia, hearing deficit, ophthalmoplegia, intractable epilepsy and elevation of serum transaminases. The liver showed mtDNA depletion, whereas the muscle mtDNA was only slightly affected. Alpers-Huttenlocher syndrome has previously been associated with mutations of polymerase gamma, a replicative polymerase of mtDNA. We show here that recessive mutations of the close functional partner of the polymerase, the Twinkle helicase, can also manifest as early encephalopathy with liver involvement, a phenotype reminiscent of Alpers syndrome, and are a new genetic cause underlying tissue-specific mtDNA depletion.
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PMID:Recessive Twinkle mutations in early onset encephalopathy with mtDNA depletion. 1792 Nov 79

A consanguineous Israeli Bedouin kindred presented with an autosomal-recessive nonlethal phenotype of severe psychomotor retardation and extrapyramidal signs, dystonia, athetosis and ataxia, mild axial hypotonia, and marked global dementia with defects in verbal and expressive communication skills. Metabolic workup was normal except for mildly elevated blood lactate levels. Brain magnetic resonance imaging (MRI) showed increased density in the putamen, with decreased density and size of the caudate and lentiform nuclei. Reduced activity specifically of mitochondrial complex III and variable decrease in complex I activity were evident in muscle biopsies. Homozygosity of affected individuals to UQCRB and to BCSIL, previously associated with isolated complex III deficiency, was ruled out. Genome-wide linkage analysis identified a homozygosity locus of approximately 9 cM on chromosome 5q31 that was further narrowed down to 2.14 cM, harboring 30 genes (logarithm of the odds [LOD] score 8.82 at theta = 0). All 30 genes were sequenced, revealing a single missense (p.Ser45Phe) mutation in UQCRQ (encoding ubiquinol-cytochrome c reductase, complex III subunit VII, 9.5 kDa), one of the ten nuclear genes encoding proteins of mitochondrial complex III.
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PMID:Mitochondrial complex III deficiency associated with a homozygous mutation in UQCRQ. 1843 46

Cerebral folate deficiency (CFD) is associated with low levels of 5-methyltetrahydrofolate in the cerebrospinal fluid (CSF) with normal folate levels in the plasma and red blood cells. The onset of symptoms caused by the deficiency of folates in the brain is at around 4 to 6 months of age. This is followed by delayed development, with deceleration of head growth, hypotonia, and ataxia, followed in one-third of children by dyskinesias (choreo-athetosis, hemiballismus), spasticity, speech difficulties, and epilepsy. The low level of 5-methyltetrahydrofolate in the CSF can result from decreased transport across the blood-brain barrier, which is most probably because of the blocking of folate transport into the CSF by the binding of folate receptor antibodies to the folate receptors in the choroid plexus. Treatment of the condition with folinic acid for prolonged periods can result in significant improvement of clinical symptoms and a return of 5-methyltetrahydrofolate levels in the CSF to normal. In view of this response to treatment in CFD and allied conditions, a case can be made for screening the CSF of patients with neurological disorders of unknown origin.
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PMID:Cerebral folate deficiency. 1926 Sep 31

Inborn errors of metabolism (IEM) are a group of genetic disorders characterized by dysfunction of an enzyme or other protein involved in cellular metabolism.(1) Most IEMs involve the nervous system (neuro-metabolic diseases or NMD). NMD often present with a complex clinical picture: psychomotor retardation and/or regression, pyramidal signs, ataxia, hypotonia and epilepsy and movement disorders.(1) Movement disorders are more frequently part of this complex picture than a predominant symptom, however in some instances the clinical picture may be summarized in an invalidating movement disorder.(2) On a phenomenology basis, one can distinguish eight main types of movement disorders: dystonia and athetosis, chorea, tremor with or without parkinsonism, ballismus, myoclonus, tics and stereotypies. Most of these abnormal involuntary movements generate from a dysfunction or a lesion in the basal ganglia, excepting myoclonus, the origin of which can vary (cortical, brainstem, basal ganglia, spinal and even peripheral nervous system).(3) Classically the most frequently observed movement disorders in NMD are: dystonia, myoclonus, chorea, tremor and parkinsonism (Fig. 1). The primary goal of this article is, departing from the literature and a large personal series, to describe the types of movement disorders most frequently observed in NMD and to discuss their clinical value in the setting of specific types of NMD.
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PMID:Movement disorders in neuro-metabolic diseases. 2001 70

IOSCA is a difficult, progressive degenerative disease causing damage to the peripheral and central nervous system. All known 24 patients are Finnish. Initial symptoms include ataxia, athetosis, ophthalmoplegia, hearing disability and muscular hypotonia. Sensory axonal neuropathy and associated optic atrophy are typical of the disease, as well as primary hypergonadotropic hypogonadism in girls. The patients are progressively severely disabled from the age of approx. eighteen months. The pathogenesis is unknown and there is no curative treatment for the disease.
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PMID:[IOSCA - Infantile onset spinocerebellar ataxia]. 2188 47

Degeneration of the cerebrum, cerebellum, and retina in infancy is part of the clinical spectrum of lysosomal storage disorders, mitochondrial respiratory chain defects, carbohydrate glycosylation defects, and infantile neuroaxonal dystrophy. We studied eight individuals from two unrelated families who presented at 2-6 months of age with truncal hypotonia and athetosis, seizure disorder, and ophthalmologic abnormalities. Their course was characterized by failure to acquire developmental milestones and culminated in profound psychomotor retardation and progressive visual loss, including optic nerve and retinal atrophy. Despite their debilitating state, the disease was compatible with survival of up to 18 years. Laboratory investigations were normal, but the oxidation of glutamate by muscle mitochondria was slightly reduced. Serial brain MRI displayed progressive, prominent cerebellar atrophy accompanied by thinning of the corpus callosum, dysmyelination, and frontal and temporal cortical atrophy. Homozygosity mapping followed by whole-exome sequencing disclosed a Ser112Arg mutation in ACO2, encoding mitochondrial aconitase, a component of the Krebs cycle. Specific aconitase activity in the individuals' lymphoblasts was severely reduced. Under restrictive conditions, the mutant human ACO2 failed to complement a yeast ACO1 deletion strain, whereas the wild-type human ACO2 succeeded, indicating that this mutation is pathogenic. Thus, a defect in mitochondrial aconitase is associated with an infantile neurodegenerative disorder affecting mainly the cerebellum and retina. In the absence of noninvasive biomarkers, determination of the ACO2 sequence or of aconitase activity in lymphoblasts are warranted in similarly affected individuals, based on clinical and neuroradiologic grounds.
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PMID:Infantile cerebellar-retinal degeneration associated with a mutation in mitochondrial aconitase, ACO2. 2240 87


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