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)

The neural cell-adhesion molecule L1 is involved in intercellular recognition and neuronal migration in the CNS. Recently, we have shown that mutations in the gene encoding L1 are responsible for three related disorders; X-linked hydrocephalus, MASA (mental retardation, aphasia, shuffling gait, and adducted thumbs) syndrome, and spastic paraplegia type I (SPG1). These three disorders represent a clinical spectrum that varies not only between families but sometimes also within families. To date, 14 independent L1 mutations have been reported and shown to be disease causing. Here we report nine novel L1 mutations in X-linked hydrocephalus and MASA-syndrome families, including the first examples of mutations affecting the fibronectin type III domains of the molecule. They are discussed in relation both to phenotypes and to the insights that they provide into L1 function.
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PMID:New domains of neural cell-adhesion molecule L1 implicated in X-linked hydrocephalus and MASA syndrome. 776 52

A 31-year-old woman, a child of consanguineous parents, who had shown mental retardation and slowness in running ability since childhood, complained of progressive spastic gait for one and a half years prior to admission. On admission, neurological examination revealed severe spastic paraplegia, mental retardation, visual disturbance, cerebellar ataxia, disturbance of deep sensation, sphincter disturbance, pes cavus and pes equinovarus. Protein content in the cerebrospinal fluid was increased to 86.1 mg/dl. Markedly reduced activity of galactosylceramidase in the leukocytes and the cultured fibroblasts confirmed the diagnosis of Krabbe's disease. T2-weighted MR images disclosed high signal areas in the deep white matter of the bilateral parieto-occipital lobes. There were also abnormal high signal bands along the bilateral pyramidal tracts from the corona radiata to the cerebral peduncle and the posterior part of the corpus callosum. The nerve conduction studies showed markedly decreased motor and sensory conduction velocities with decreased amplitudes. Visual evoked potentials showed prolongation of the right P100 latency. Auditory brainstem responses showed prolonged interpeak latencies between I-V peaks. Somatosensory evoked potentials showed prolongation of the N20 latencies. The morphometric histopathological analysis of the sural nerve revealed a decrease in the density of myelinated fibers and the presence of myelinated fibers with thin myelin sheath relative to the size of transverse area of axon. There were linear inclusion bodies in the cytoplasm of Schwann cells on electron microscopic examination. This is the first report in Japan of a patient with Krabbe's disease who survived after adolescence.
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PMID:[An adult patient with Krabbe's disease--the first case reported in Japan]. 812 80

MASA syndrome includes mental retardation, adducted thumbs, shuffling gait and aphasia or speech delay. MASA syndrome, X-linked hydrocephalus and X-linked spastic paraplegia have been linked to the same markers on Xq28 and perhaps represent variation in the clinical expression of the same gene or manifestations of different mutant alleles. The present family includes five males in two generations with borderline to mild mental retardation (5/5), speech delay (5/5), spastic paraplegia (5/5), adducted thumbs (2/5) and marked hydrocephalus (1/5). Of these males, four were evaluated by MRI or CT scan and all four were determined to have partial to complete agenesis of the corpus callosum (ACC). DNA studies confirm linkage to Xq28 probe St14 (DXS52) with a lod score of 2.86 and no recombination. It is not known if X-linked ACC is linked to the same Xq28 region.
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PMID:Agenesis of the corpus callosum associated with MASA syndrome. 830 64

Epilepsy rarely occurs in patients with hereditary spastic paraplegia (HSP), and is not included in the description of the 'complicated' form of HSP by Harding. We report 3 patients with HSP in a family of two generations. Two of them also had epilepsy, mental retardation and hearing impairment. The disorder was inherited as an autosomal dominant trait.
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PMID:Hereditary spastic paraplegia associated with epilepsy, mental retardation and hearing impairment. 833 6

The most common inherited form of hydrocephalus, X linked hydrocephalus (HSAS), is characterised by mental retardation, adducted thumbs, and spastic paraplegia. Genetic analysis has mapped the locus for HSAS to subchromosomal band Xq28 within a region of approximately 2 megabases of DNA. In order to refine the location of the disease gene we have conducted genetic linkage analysis with Xq28 marker loci in four additional HSAS families. A lod score of 4.26 with polymorphic marker DXS52 (St14) confirms the linkage of HSAS to Xq28. Identification of a recombination event between the HSAS gene and Xq28 loci F8C and DXS605 (2-19) reduces the size of the interval likely to contain the disease locus to about 1.5 megabases, the distance between DXS605 and DXS52. The locus for neural cell adhesion molecule, L1CAM, maps within this interval and therefore represents a candidate gene for HSAS.
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PMID:Refining the genetic location of the gene for X linked hydrocephalus within Xq28. 847 7

L1 is a neuronal cell adhesion molecule with important functions in the development of the nervous system. The gene encoding L1 is located near the telomere of the long arm of the X chromosome in Xq28. We review here the evidence that several X-linked mental retardation syndromes including X-linked hydrocephalus (HSAS), MASA syndrome, X-linked complicated spastic paraparesis (SP1) and X-linked corpus callosum agenesis (ACC) are all due to mutations in the L1 gene. The inter- and intrafamilial variability in families with an L1 mutation is very wide, and patients with HSAS, MASA, SP1 and ACC can be present within the same family. Therefore, we propose here to refer to this clinical syndrome with the acronym CRASH, for Corpus callosum hypoplasia, Retardation, Adducted thumbs, Spastic paraplegia and Hydrocephalus.
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PMID:CRASH syndrome: clinical spectrum of corpus callosum hypoplasia, retardation, adducted thumbs, spastic paraparesis and hydrocephalus due to mutations in one single gene, L1. 855 2

We report on clinical and cytogenetic data on 5 children and 2 adults with a de novo inverted duplication of the short arm of chromosome 8, and we give a review of 26 patients from the literature. The clinical picture in young children is characterized by minor facial anomalies, hypotonia, and severe developmental delay. In older patients the facial traits are less characteristic, spastic paraplegia develops, and severe orthopedic problems are frequent. Psychomotor retardation is always severe-to-profound. Duplication of 8p21-p22 results in a clinically recognizable multiple congenital anomalies/mental retardation (MCA/MR) syndrome. It is shown that in all patients examined, the duplication was accompanied by a deletion of the most terminal part of 8p.
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PMID:Inversion duplication of the short arm of chromosome 8: clinical data on seven patients and review of the literature. 859 64

Two patients with X-chromosomal hydrocephalus internus (aqueduct stenosis, clasped thumbs, mental retardation and spasticity) habe been described. In both cases the family history revealed further affected relatives. The intra- and interfamilial variability of this rare X-chromosomal recessive disease will be demonstrated. In this context differentialdiagnoses like X-linked MASA syndrome and X-linked spastic paraplegia have been discussed on the basis of a variable expressivity of different mutations in the same gene.
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PMID:[X-chromosomal recessive hydrocephalus internus: a separate disease picture? 2 further case reports and review of the literature]. 867 3

Autosomal dominant, autosomal recessive and X-linked recessive varieties of spastic paraplegia have been recognized. Recently, Japanese patients with complicated form of autosomal recessive hereditary spastic paraplegia (HSP) associated with hypoplasia of the corpus callosum have been reported by Iwabuchi et al. We describe a patient with complicated HSP (Iwabuchi type) and cataracta. A 38-year-old man (his parents were a second cousin) was born uneventfully. His motor development was normal. Motor and mental dysfunctions were noticed during the lower classes of an elementary school. He could ride a bicycle at 18 years old but gradually developed galt disturbance and confined to wheelchair since 35 years. He was admitted to our hospital on February 25, 1994. A neurological examination showed mental retardation, dementia, cataracta, cerebellar ataxia, rigidity, spasticity, severe atrophy of the distal muscles of his extremities, paraparesis, hyperreflexia, positive Hoffmann reflexes and Babinski signs, pes cavus and hammer toes. Brain MRI showed thinning of corpus callosum. Clinical and laboratory findings did not support a diagnosis of metabolic disorders showing spastic paraparesis including adrenomyeloneuropathy, Globoid leukodystrophy, metachromatic leukodystrophy, cerebrotendinous xanthomatosis, Arginase deficiency. We considered that our patient was complicated form of HSP (Iwabuchi et al). However, cataract has not been found in Iwabuchi type of HSP. We discussed here other reports showing cataracta with spastic paraparesis.
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PMID:[A case of complicated form of hereditary spastic paraplegia associated with hypoplasia of the corpus callosum and cataracta]. 877 6

X-linked hereditary spastic paraplegias (HSP) present with two distinct phenotypes, pure and complicated. The pure form is characterized by spasticity and gait difficulties but lacks the additional features (nystagmus, dysarthria, mental retardation) present in the complicated form. The complicated form is heterogeneous, caused by mutations of the L1CAM gene at Xq28 (SPG1) or the PLP gene at Xq22 (SPG2) that is allelic to Pelizaeus-Merzbacher disease (PMD). Since in one kindred (K313) the pure form of HSP was also mapped to Xq22, this raises the issue as to whether a pure form of HSP exists that is allelic to X-linked complicated HSP (SPG2) and PMD. To answer this question, we carried out linkage analysis in a new pedigree with pure HSP (K101) and refined linkage in pedigree K313. The PLP gene was also screened for mutation by direct sequencing and reverse-transcriptase polymerase chain reaction (RT-PCR). In both families, the disease locus mapped to Xq22 with Lod scores at zero recombination of 5.3 for COL4A5 2B6 in K313 and 2.4 for DXS101 in K101. A T to C transition in exon 5 of the PLP gene was identified from affected individuals of K313. This transition causes a Ser to Pro mutation in the major extracellular loop of PLP/DM20. This finding demonstrates that a form of X-linked pure spastic paraplegia, X-linked complicated HSP (SPG2) and PMD are allelic disorders. There was no evidence of mutations in either coding sequences or the intron/exon junctions of PLP in pedigree K101, suggesting that the disease-producing mutation may be in the noncoding portions of PLP or in a nearby gene.
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PMID:Refined genetic mapping and proteolipid protein mutation analysis in X-linked pure hereditary spastic paraplegia. 878 Jan 1


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