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

Three Japanese patients with carbonic anhydrase II (CAII) deficiency from three families were described. The parents of one patient were unrelated, the parents of each of the other two patients were first cousins. All the patients had renal tubular acidosis, osteopetrosis, symmetrical cerebral calcification and mental retardation. They exhibited poor activity and poor appetite in the neonatal period, and then developed psychomotor retardation. Two of them were diagnosed as having osteopetrosis at 10 months and 36 years of age, respectively, and the other as having osteomalacia at 28 years of age. All patients had recurrent episodes of muscle weakness. The CAII enzyme activity and protein levels in red blood cells in each of the three patients were deficient. Their parents exhibited approximately 50% normal levels of CAII activity and protein. This is the first report of patients with CAII deficiency in the Japanese population.
 ...
PMID:Carbonic anhydrase II deficiency in three unrelated Japanese patients. 812 74

We report myoclonic epilepsy with ragged-red fibers (MERRF) syndrome in a Chinese family with confirmed mitochondrial DNA point mutation. Six members of the family including the grandmother, two siblings, and three grandchildren were affected. Among them, action myoclonus was seen in five; short stature, muscle weakness, and mental retardation in four; lactic acidosis, hearing impairment, and ataxia in two; and seizures in one. Muscle biopsy from two affected siblings revealed ragged-red fibers and abundant subsarcolemmal mitochondria with paracrystalline inclusions. Pedigree analysis suggests a maternal transmission. Analysis of mitochondrial DNA showed a point mutation from A to G at the 8344th nucleotide position located in the tRNA(Lys) gene. To our knowledge, this is the first report of MERRF syndrome with such genetic defect from a Chinese family. The present and previous reports support the notion that mitochondrial DNA point mutation at the 8344th nucleotide position is the most common cause of MERRF syndrome.
 ...
PMID:Myoclonic epilepsy with ragged-red fibers (MERRF) syndrome: report of a Chinese family with mitochondrial DNA point mutation in tRNA(Lys) gene. 793 36

Congenital muscular dystrophy (CMD) is a concept applied to infants showing muscular weakness and hypotonia at birth, with myopathic changes which are histopathologically similar to those of muscular dystrophy. Patients with Fukuyama-type CMD (FCMD), characterized by progressive muscular dystrophy, mental retardation and occasionally, convulsions, are more frequently seen in Japan than those with non-Fukuyama type CMD (NFCMD). FCMD has been regarded as a distinct clinical and pathological entity, although the nosologic status of CMD is still controversial. A 24-year-old man had exhibited hypotonia and weakness at birth and delay in early development. During childhood, his muscular weakness improved, and he rode a bicycle and enjoyed skiing. However, his strength began to deteriorate at the age of 19 years. Neurological examination on admission revealed prominent muscular wasting and weakness, predominantly in the proximal limbs. He had ocular involvement (corneal opacity and slow saccades), sensorineural deafness, and a high-arched palate, saddle nose and funnel chest as anomalous conditions. Serum CK was moderately elevated and EMG showed myogenic patterns. A muscle biopsy specimen of the left biceps brachii was dystrophic, showing increased variation in fiber size with fibrous tissue proliferation, an increased number of centralized nuclei, fiber splitting and degenerating/regenerating fibers. Those findings were compatible with those seen in NFCMD. In Japan, only one patient with NFCMD who was followed to adulthood has been reported. This patient's symptoms progressed very slowly. The present patient's course of illness was stable during childhood but progressive in early adulthood. It suggests heterogeneous clinical expression of the disease.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[A case of non-Fukuyama type congenital muscular dystrophy with progression in early adulthood, ocular involvement, and sensorineural deafness]. 837 Feb 3

A 19 year-old patient, second child of a non consanguinous marriage, was evaluated because of the patient progressive mental retardation and muscular weakness from infancy. Six maternal uncles non had died of unknown cause in the first year of life, and his mother had 3 spontaneous miscarriages; the two sisters of the patient were healthy. Clinical examination demonstrated a severe mental retardation, discrete proximal muscular weakness as well as universal areflexia. The muscular enzymes were elevated and the electrophysiologic study showed normal neurographic parameters and abundant generalized spontaneous activity with a mixed type contraction pattern. Histologic examination of the muscle was diagnosed as myopathy with atrophy of type I fibers and central nuclei and upon cranial nuclear magnetic resonance (NMR) images suggestive of perinatal hypoxic-ischemic encephalopathy were observed.
 ...
PMID:[Centronuclear myopathy]. 844 42

Charcot-Marie-Tooth (CMT) disease is the commonest inherited peripheral neuropathy. The clinical study of 45 patients with CMT is presented. They were derived from Antonio Pedro Hospital of Universidade Federal Fluminense in Niteroi, RJ, Brazil. Such patients could be divided by the motor conduction velocity in two types: a demyelinating form or type I (11 cases) and an axonal form or type II (34 cases). The disease was inherited as an autosomal dominant trait in 23 patients and as an autosomal recessive trait in 7 cases. In 15 patients the disorder was sporadic. The age of onset was in most of our cases before the 20 years. All of them had distal weakness in lower limbs. 38.2% had also distal weakness in upper limbs. 80% had distal wasting of the lower limbs and 50% had distal wasting of upper limbs. The tendon reflexes were absent in 64% in lower limbs and in 28% in upper limbs. The sensitive impairment in the distal regions of the extremities was mild in most patients. We found enlargement of peripheral nerves in 7 patients of type I. Pes cavus was present in 21 cases and scoliosis in 7. We found postural tremor of hands in 6 patients. In 9 cases there were rare features as mental retardation, trigeminal nevralgia, optic atrophy, deafness and calf enlargement. In most of our cases the clinical course was very slow progressive. A greater severity was seen in our sporadic cases.
 ...
PMID:[Charcot-Marie-Tooth disease. Clinical study in 45 patients]. 858 9

We report four patients, currently aged 15, 17, 19, and 42 years, with X-linked dystrophinopathy who presented with mental retardation (IQ range, 60-68) and psychiatric disturbance in the absence of muscle weakness. All patients had elevated serum creatine kinase and dystrophic changes on muscle biopsy. There were alterations in the size and abundance of dystrophin on immunohistochemistry and immunoblotting in all cases, consistent with a molecular diagnosis of Becker's muscular dystrophy. Two patients had deletions of the dystrophin gene on DNA analysis. These findings suggest that Becker's muscular dystrophy may be associated with a predominantly neuropsychiatric presentation and that dystrophinopathy should be considered in the differential diagnosis of unexplained cognitive or psychiatric disturbance in males. Serum creatine kinase may provide an adequate screening test in this clinical situation.
 ...
PMID:Cognitive dysfunction as the major presenting feature of Becker's muscular dystrophy. 861 13

Familial polyneuropathy mimicking Charcot-Marie-Tooth disease associated with parkinsonism and dementia has been reported in literature. We present with similar peroneal muscular atrophy, rigidity of upper extremities, severe peripheral neuropathy, mental retardation and diabetes mellitus. The patient, a 42-year-old man, developed progressive muscle weakness, mental retardation and difficulty in walking in childhood. Because of his pes cavus, he had three surgical operations. At the age of 20 years, he developed distal muscular atrophy of lower limbs. On neurological examination, all limb muscles were atrophic, especially in lower one third of the thigh. Rigidity was noted in the upper extremities. Deep tendon reflexes were hyperactive in the upper and diminished in the lower extremities. Muscle CT revealed low density areas in all the muscles examined, specially in the gastrocnemius and anterior tibial muscles. Needle EMG showed neurogenic change in the forearm, but not in the lower limbs, because of no voluntary contractions obtained due to severe muscle atrophy. Marked slowing of motor conduction velocity with muscle action potentials of very low amplitude was found in the ulnar nerve. Muscle action potentials were not elicited in the median and peroneal nerves. Sensory action potentials were not elicited from the median, ulnar and sural nerves. These findings were consistent with axonal polyneuropathy. In the sural nerve biopsy, the densities of myelinated fibers were markedly decreased. However, unmyelinated fiber densities were relatively preserved. Onion bulb formation was not found. This patient may be classified into hereditary motor-sensory neuropathy (HMSN) type II based on the clinical findings delayed nerve conduction velocities and axonal degeneration in the sural nerve. He has also diabetes mellitus. CT of the brain revealed nothing particular. He is one of members with familial Parkinson's disease (PD) developed in Sagamihara. Peroneal muscular atrophies are not necessarily associated with PD, though it has been occasionally complicated in various neuro-degenerative diseases including parkinsonism. We are now following the patient to detect the symptom of Parkinson's disease for early treatment.
 ...
PMID:[An unusual case of peroneal muscular atrophy with rigidity, polyneuropathy, mental retardation, and diabetes mellitus developed in familial Parkinson's disease]. 866 30

DNA markers on the X chromosome were used to map the locus for an unusual form of X-linked recessive hereditary motor and sensory neuropathy with associated deafness and mental retardation in a three-generation family that was originally reported by Cowchock et al. (Am, J. Hum. Genet. 35: 85A, 1993; Am. J. Med. Genet. 20: 307-315, 1985). This family included seven affected males, three obligate carrier females, and four unaffected males. The patients were severely affected within the first few years of life with distal weakness, muscle atrophy, sensory loss, areflexia, pes cavus, and hammer toes. Five of the seven affected males showed associated deafness, and three of these five individuals also presented with mental retardation or social developmental delay. Motor nerve conduction velocities in affected males were normal to mildly delayed, and sensory conduction was markedly abnormal. Heterozygous females were asymptomatic. Close linkage to the Xg blood group locus (Xp22) and the PGK locus (Xq13) was previously excluded in this family, while weak linkage of the disease gene to DXYS1 (XQ21.3) was suggested. Our current linkage studies and haplotype analysis of 19 microsatellite markers on the long arm of the X chromosome demonstrate that DXS425 (Xq24) and HPRT (Xq26.1) are flanking markers and that the disease gene is closely linked to the markers DXS1122, DXS994, DXS737, DXS1206, and DXS1047.
 ...
PMID:A locus for axonal motor-sensory neuropathy with deafness and mental retardation maps to Xq24-q26. 866 89

Duchenne muscular dystrophy (DMD) is an X-linked genetic disorder primarily affecting young boys, often causing mental retardation in addition to the well-known progressive muscular weakness. Normal dystrophin expression is lacking in skeletal muscle and the CNS of both DMD children and the mdx mouse model. To date, 31P-magnetic resonance spectroscopy (MRS) has shown in vivo several abnormalities within skeletal muscle of mdx mice and DMD boys. In this study, we determined whether similar abnormalities occur in mdx brain in vivo by using 31P-MRS in addition to metabolite and enzyme analysis to study cerebral metabolism. An increased inorganic phosphate (P(i))/phosphocreatine (PCr) and pH was found in vivo for mdx brain compared with controls, and biochemical analysis showed a reduction in total creatine, an increased extracellular and decreased intracellular volume in mdx brain. No differences were found in any glycolytic or mitochondrial maximal enzyme activities. These changes are discussed with respect to the biochemical changes found in muscle from DMD patients and mdx mice. It is proposed that these biochemical changes may be a factor in the reduced cognitive capacity of mdx mice and some DMD children.
 ...
PMID:Brain metabolism is abnormal in the mdx model of Duchenne muscular dystrophy. 867 81

Myotonic dystrophy (DM) is an autosomal-dominant, multisystemic disorder characterized by myotonia, progressive muscle atrophy and weakness, cardiac conduction defect, mental retardation, and cataracts. The phenotypic expression of DM varies from asymptomatic adults to severely affected neonates with congenital DM (CDM). DM shows genetic anticipation, an increase in disease severity and earlier age of onset in successive generations. The molecular basis of DM mutation is an unstable trinucleotide (CTG) repeat located in the 3' end of a transcript that encodes a myotonin-protein kinase. Normal populations have 5 to about 30 CTG repeats, where DM patients have 50-2,000 such repeats. The CTG repeat number is expanded in DM patients when transmitted from parent to child severity. An approximate correlation has been demonstrated between the degree of CTG repeat expansion and clinical severity. The largest repeat sizes are disclosed in CDM. Furthermore, we presented haplotype analysis of CDM families and disclosed localization of myotonic dystrophy protein kinase in DM muscle. DM kinase mRNA was decreased in various tissues of CDM patient.
 ...
PMID:[DNA diagnosis in myotonic dystrophy]. 872 68


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