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

This study presents the clinical findings on seven children from Malta (population 385,000). All of them had early motor delay and a significant degree of cognitive impairment. Diurnal variation of the motor impairments was clear in six out of seven of the subjects and oculogyric crises occurred from an early stage also in six out of the seven. Five out of seven had clear evidence of dystonia but the early picture was dominated by hypotonia in five. Two had early Parkinsonian tremor and chorea was seen in four, although in two this was attributable to the use of L-dopa. Three had early bulbar involvement. In all, although minor motor problems persisted, the response to L-dopa was dramatic and there was a need to balance improvement in dystonia against aggravation of chorea. The majority were not able to walk until they were treated. Increased doses of L-dopa were required in hot weather, to which they were sensitive. Despite a good response of improved motor ability and abolition of oculogyric crises, there was no obvious change in cognitive function with learning remaining in the moderate impairment range. This report widens the phenotype of dopa-responsive motor disorders and the range of young children with primary motor delay (cerebral palsy) who need a clinical trial of L-dopa. All of the subjects had the same novel mutation in the tetrahydrobiopterin pathway involving sepiapterin reductase, and no abnormality in the gene encoding guanosine triphosphate cyclohydrolase 1. Clinically and molecularly the condition shows autosomal recessive inheritance.
 ...
PMID:Sepiapterin reductase deficiency: a congenital dopa-responsive motor and cognitive disorder. 1604 44

Pyruvate dehydrogenase deficiency is a major cause of primary lactic acidosis and neurological dysfunction in infancy and early childhood. Most cases are caused by mutations in the X-linked gene for the E1alpha subunit of the complex. Mutations in DLAT, the gene encoding dihydrolipoamide acetyltransferase, the E2 core component of the complex, have not been described previously. We report two unrelated patients with pyruvate dehydrogenase deficiency caused by defects in the E2 subunit. Both patients are less severely affected than typical patients with E1alpha mutations and both have survived well into childhood. Episodic dystonia was the major neurological manifestation, with other more common features of pyruvate dehydrogenase deficiency, such as hypotonia and ataxia, being less prominent. The patients had neuroradiological evidence of discrete lesions restricted to the globus pallidus, and both are homozygous for different mutations in the DLAT gene. The clinical presentation and neuroradiological findings are not typical of pyruvate dehydrogenase deficiency and extend the clinical and mutational spectrum of this condition.
 ...
PMID:Clinical and genetic spectrum of pyruvate dehydrogenase deficiency: dihydrolipoamide acetyltransferase (E2) deficiency. 1604 40

Neurophysiologic abnormalities are frequently seen in organic acidemias, but knowledge of the specific changes in the different types of organic acidemias is lacking. We studied electroencephalogram (EEG), visual evoked potential (VEP) and brain-stem auditory evoked response (BAER) in seven children with glutaric aciduria type I (GA1) to assess the neurophysiologic features in this rare inborn error of metabolism. Age at the time of the diagnosis ranged between 3 months and 36 months. Age at the time of neurophysiologic evaluation ranged between 11 months and 36 months. At the time of neurophysiologic evaluation, severe global developmental delay was seen in four patients, dystonia in four patients, motor delay in two patients, and axial hypotonia in two patients; macrocephaly, spasticity, moderate mental retardation and borderline intelligence were each seen in one patient. One patient had autistic features characterized by lack of language and social skills, poor eye contact and stereotypical behavior. Three of seven patients showed abnormal EEG findings. Two patients showed asymmetry with intermittent occipital delta slowing in one hemisphere. This finding probably indicates underlying cerebral dysfunction, and is not a specific feature. However, it suggests that these patients may develop abnormal EEG features during the course of the disease, and thus a baseline EEG may be useful for comparison over time. One patient showed high amplitude bursts of beta in the occipital regions with left predominance while on clonazepam and baclofen. We believe this finding was due to medication effect, and that what we observed was an exaggarated response to benzodiazepine. The clinical significance of this finding is unclear. VEP and BAER were available in four patients, and we found abnormalities in three of them. Neurophysiologic evaluation may be helpful in patients with GA1 as in other types of organic acidemias to help detect subtle changes that are not reflected by neurological examination or neuroimaging studies, and it may guide future treatment plans. Detailed neurophysiologic analysis in a large series of GA1 may yield further information regarding the extent of cerebral dysfunction.
 ...
PMID:Neurophysiologic features in glutaric aciduria type I. 1605 56

The relative frequencies of different spinocerebellar ataxias (SCAs) vary widely among different ethnic groups, presumably due to a founder effect. We investigated the relative prevalence of SCA1-3, 6-8, 12, 17; dentate-rubro-pallidoluysian atrophy; and Friedreich's ataxia (FRDA) in Serbian patients with adult-onset (>20 years of age) hereditary and sporadic SCAs, and compared clinical features of patients with genetically confirmed SCAs. A total of 108 patients from 54 families (38 apparently dominant [ADCA] and 16 apparently recessive) with adult-onset hereditary ataxia and 75 apparently sporadic patients were assessed. Of 38 families with ADCA, 13 (34%) were positive for an expansion in an SCA1 and 5 families (13%) for an expansion in an SCA2 allele. In 20 families (53%), no expansions have been identified in any of the analyzed genes. Gaze palsy, spasticity, and hyperreflexia were significantly more common in SCA1, whereas slow saccades, hypotonia, hyporeflexia, and dystonia prevailed in SCA2 patients. Among the 16 families with an apparently recessive mode of ataxia inheritance, 4 (25%) were identified as having the FRDA mutation. Ataxia-causing mutations were identified in 8 (10.6%) of patients with apparently sporadic adult-onset ataxia.
 ...
PMID:Frequency analysis and clinical characterization of different types of spinocerebellar ataxia in Serbian patients. 1670 60

Little information is available on the long-term course and adult outcome of patients with 6-pyruvoyl-tetrahydropterin synthase (PTPS) deficiency. We describe the course of a 32-year-old woman with hypotonia, dystonia, choreoathetosis, mental retardation, behavioral disturbances, and incomplete puberty due to PTPS deficiency. From the age of 6 months she developed progressive hypotonia and choreoathtetoid movements despite good control of hyperphenylalaninemia. Tetrahydrobiopterin deficiency was diagnosed at age 3 years. She had a dramatic response to L-dopa, which persisted at a stable dose for 29 years. Reducing the L-dopa dose led to severe axial hypotonia and limb dystonia, and increasing it led to florid abnormal movements and behavioral disorders. This report illustrates the role of dopamine modulation in motor, psychiatric, and endocrine functions.
 ...
PMID:Long-term follow-up and adult outcome of 6-pyruvoyl-tetrahydropterin synthase deficiency. 1616 Nov 43

A 12-month-old boy diagnosed with propionic acidemia underwent gastrostomy. The patient's general state was good and he was alert, but with reduced muscular tone (unstable when seated with support, floppy head) and with dystonic movements in all extremities. An electroencephalogram showed slightly slowed brain activity. The patient was being treated with a low protein diet, phenobarbital, L-carnitine, L-isoleucine, and biotin. Surgery was carried out in satisfactory conditions with general anesthesia without opioids combined with infiltration of the surgical wound with local anesthetic. Recovery from anesthesia was rapid and free of complications. Propionic acidemia is caused by mitochondrial propionyl coenzyme carboxylase deficiency. Most patients have episodes of severe metabolic ketoacidosis as a result of excessive protein intake, delayed development, vomiting, gastroesophageal reflux, lethargy, hypotonia, and convulsions. The anesthetic approach involves avoiding triggers of metabolic acidosis (such as fasting, dehydration, hypoxemia, and hypotension) and preventing airway complications. Agents that metabolize propionic acid (such as succinylcholine, benzylisoquinoline neuromuscular blocking agents, and propofol) are not used, as they can exacerbate acidemia. We also believe that using local or regional anesthesia in combination with general anesthesia without opiates is safe and effective for controlling pain during surgery and postoperative recovery, as that combination avoids respiratory depression in these patients, who are highly sensitive to opiates.
 ...
PMID:[Infant boy with propionic acidemia: anesthetic implications]. 1620 Sep 24

Aromatic l-aminoacid decarboxylase (AADC) deficiency is a neurotransmitter defect leading to a combined deficiency of catecholamines and serotonin. Patients are usually detected in infancy due to developmental delay, hypotonia, and extrapyramidal movements. Diagnosis is based on an abnormal neurotransmitter metabolite profile in CSF and reduced AADC activity in plasma. An elevation of vanillactic acid (VLA) has been described as the only abnormality detected in organic acid analysis (OA) of urine. We report a patient who presented in the neonatal period with lethargy, hypotonia, metabolic acidosis, and hypoglycemia. Blood ammonia, lactic acid, and acylcarnitines were normal, but OA of a urine sample showed a small increase of VLA, raising the suspicion of AADC deficiency. The patient was lost to follow-up until the age of 8 months, when he presented with dystonia, abnormal movements, oculogyric crises, and hypothermia. Repeat OA showed not only increased levels of VLA, but also increased vanilpyruvic acid (VPA), N-acetyl-vanilalanine (AVA) and N-acetyl-tyrosine (NAT). Neurotransmitter analysis in CSF showed increased vanilalanine (1200 nmol/L, ref<100) with decreased levels of 5-hydroxy-indoleacetic acid (5-HIAA, < 5 nmol/L; ref 152-462), homovanillic acid (HVA, 83 nmol/L; ref 302-845), and methoxy-hydroxy-phenyl-glycol (<5 nmol/L; ref 51-112). AADC activity in plasma was nearly undetectable. In the urine, low excretion of vanilmandelic acid (<0.3 micromol/mmol creat; ref 0.3-20) and 5-HIAA (0.9 micromol/mmol creat; ref 4-18), was found, but HVA was normal and dopamine even elevated. This contradictory phenomenon of hyperdopaminuria has been described earlier in AADC deficient patients. We postulate that VPA and AVA could originate from vanilalanine (through a transaminase and an acetylase respectively), while NAT could originate from tyrosine through an AA acetylase. This report expands the clinical presentation of AADC deficiency and adds new markers of the disease for OA analysis, improving detection of AADC deficient patients in general metabolic screening procedures.
 ...
PMID:Aromatic l-aminoacid decarboxylase deficiency: unusual neonatal presentation and additional findings in organic acid analysis. 1628 91

The objective of this study is to better understand the relationship between neuroradiologic and clinical characteristics in holoprosencephaly (HPE) using the multivariate analysis called factor analysis. HPE is a brain malformation characterized by incomplete cleavage of the cerebral hemispheres and deep gray structures. We performed evaluations on 89 children with HPE that included their history, developmental assessment, and physical examination. Ten clinical variables included in factor analysis were the grade of spasticity, dystonia, choreoathetosis, hypotonia, mobility, upper extremity/hand function, expressive language, feeding/swallowing difficulty, endocrinopathies, and temperature dysregulation. Five neuroimaging variables graded by pediatric neuroradiologists were the grade of HPE (from least to most severe: lobar, semilobar, and alobar) and the degree of non-separation of caudate, lentiform, thalamic, and hypothalamic nuclei. Factor analysis using principle component extraction and varimax rotation was utilized. Four significant factors were identified: (1) neuroimaging/developmental factor, (2) motor factor, (3) hypothalamic/oromotor factor, and (4) hypotonia factor. These four factors accounted for 65.2% of the variance. In this factor analysis of HPE patients, we were able to reduce the large number of clinical and radiological variables into four factors. These factors and the constructs underlying them provide structure to the data and provide key parameters for future studies involving neurodevelopmental outcomes in HPE.
 ...
PMID:Factor analysis of neuroanatomical and clinical characteristics of holoprosencephaly. 1650 93

Lesch-Nyhan disease (LND) is caused by deficiency of the purine salvage enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT). Affected individuals exhibit over-production of uric acid, along with a characteristic neurobehavioural syndrome that includes mental retardation, recurrent self-injurious behaviour and motor disability. Prior studies involving relatively small numbers of patients have provided different conclusions on the nature of the motor disorder. The current study includes the results of a multi-centre international prospective study of the motor disorder in the largest cohort of patients studied to date. A total of 44 patients ranging from 2 to 38 years presented a characteristic motor syndrome that involved severe action dystonia superimposed on baseline hypotonia. Although some patients also displayed other extrapyramidal or pyramidal signs, these were always less prominent than dystonia. These results are compared with a comprehensive review of 122 prior reports that included a total of 254 patients. Explanations for the differing observations available in the literature are provided, along with a summary of how the motor disorder of LND relates to current understanding of its pathophysiology involving the basal ganglia.
 ...
PMID:Delineation of the motor disorder of Lesch-Nyhan disease. 1654 99

The diagnosis of a 14-year-old girl with a new homoallelic mutation in the sepiapterin reductase (SR) gene is reported. Initially she presented at the age of 2 with hypotonia and mild cognitive developmental delay, and was diagnosed as having mild methylmalonic aciduria, which was recently identified as methylmalonylCoA racemase deficiency, a new defect in valine-isoleucine metabolism. After a 12-year progression of her neurologic condition, which had made her wheelchair-bound at the age of 6, dystonia with diurnal variation had become apparent. At the age of 14 this finding led to rapid diagnosis of SR deficiency. The diagnostic approach with CSF neurotransmitter and pterins analysis and combined phenylalanine/BH(4) loading test, and finally measurement of sepiapterin in CSF is illustrative for the diagnosis of SR deficiency. As in all other patients with this new defect, very low levels of homovanillic acid and 5-hydroxyindoleacetic acid and high levels of biopterin and sepiapterin in the CSF are the diagnostic hallmark. The girl improved dramatically on treatment with L-DOPA and 5-hydroxytryptophan. The initial diagnosis of methylmalonic aciduria may afterwards be considered to have not significantly contributed to her clinical condition and only has led to a long delay of the clinically relevant diagnosis of SR deficiency. Although the clinical condition of this recently recognized autosomal recessive defect in pterin metabolism is complex and many symptoms can occur in variable severity and time of onset, dystonia with diurnal variation is a characteristic finding, as shown in nearly all patients described so far. The rapid and favourable response on treatment with L-DOPA warrants the classification of SR deficiency as another autosomal recessive type of DOPA-responsive dystonia (DRD). This classification is important to improve the awareness of clinicians that more than one metabolic defect can underlie the phenotype of a DOPA-responsive dystonic disorder and that dystonia should always trigger a rapid diagnosis of the underlying neurotransmitter synthesis defect, in view of the excellent treatability of a DRD.
 ...
PMID:Sepiapterin reductase deficiency an autosomal recessive DOPA-responsive dystonia. 1665 Jul 84


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>