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)

Autosomal recessive hereditary spastic paraplegia with thinning of the anterior corpus callosum (ARHSP-TCC) due to mutations in SPG11 on chromosome 15q (MIM610844) is the single most common cause of ARHSP. It is characterized by slowly progressive paraparesis and peripheral neuropathy. Although cognitive impairment, sometimes diagnosed as mental retardation, is an almost invariable feature, the extent and specific neuropsychological features are not fully understood. We report a comprehensive neuropsychological assessment in two ARHSP-TCC patients harbouring mutations in SPG11. A specific impairment in executive functions occurring even before cognitive decline, may be considered the core of the neuropsychological profile of patients harbouring mutations in SPG11.
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PMID:Cognitive profile in spastic paraplegia with thin corpus callosum and mutations in SPG11. 2057 89

Carriers of a ring chromosome 22 are mentally retarded and show variable facial dysmorphism. They may also present with features of neurofibromatosis type II (NF2) such as vestibular schwannomas and multiple meningiomas. In these cases, tumourigenesis has been suspected to be caused by the loss of both alleles of the NF2 gene, a tumour suppressor localized in 22q12.2. Here, we describe an 18-year-old patient with constitutional ring chromosome 22 and mental retardation who developed rapid-onset spastic paraparesis at the age of 15 years. The causative spinal meningioma at the level of T3, which compressed the spinal cord, was surgically removed, and the patient regained ambulation. Array comparative genomic hybridization (array CGH) and multiplex ligation-dependent probe amplification (MLPA) analyses in blood revealed a terminal deletion in 22q13.32, not comprising the NF2 gene. In tumour tissue, loss of the whole ring chromosome 22 including one NF2 gene due to mitotic instability constituted the likely first hit, while a point mutation in the other allele of the NF2 gene (c.784C>T, p.R262X) was shown as second hit. We review all cases from the literature and suggest clinical guidelines for surveillance of patients with ring chromosome 22.
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PMID:Ring chromosome 22 and neurofibromatosis type II: proof of two-hit model for the loss of the NF2 gene in the development of meningioma. 2117 98

The hereditary spastic paraplegias (HSP) are a heterogeneous group of genetic neurodegenerative disorders in which the main feature is progressive spasticity of the lower limbs due to pyramidal tract dysfunction. Clinically HSP are divided into two forms: a pure form that presents with progressive lower limb spasticity and weakness, sensory signs and bladder dysfunction, and a complicated form, associated with more extensive neurological and extra neurological signs as well as pathological findings on brain imaging. The clinical variability observed in HSP is supported by the large underlying genetic heterogeneity. Hereditary spastic paraplegia with thin corpus callosum (HSP-TCC) is a frequent subtype of complicated HSP clinically characterized by a slowly progressive spastic paraparesis with cognitive impairment and thin corpus callosum (TCC). SPG11, the most frequent gene associated with HSP-TCC, encodes spatacsin, a protein of unknown function. We describe two siblings from an Arabic consanguineous family with slowly progressive spastic paraparesis, mental retardation, seizures, thin corpus callosum and periventricular white matter abnormalities. Homozygosity mapping identified a novel single candidate region of 7.3 Mb on chromosome 1p13.2-1p12. The finding of a new locus for AR-HSP-TCC further demonstrates the extensive genetic heterogeneity of this condition.
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PMID:A new locus (SPG47) maps to 1p13.2-1p12 in an Arabic family with complicated autosomal recessive hereditary spastic paraplegia and thin corpus callosum. 2144 Feb 62

Allgrove syndrome (triple A) is a rare autosomal recessive disease. The classic triad includes, congenital adrenal insufficiency due to ACTH resistance, achalasia of the cardia and alacrimia. Neurological abnormalities are associated with autonomic neuropathy, sensory and motor defects, deafness, mental retardation, Parkinsonism and dementia. The gene responsible is the ADRACALIN or AAAS encoding a protein called ALADIN. We report a case of a 19 year-old male, assessed when he was 10 years old in our department due to suspected storage disease. Mild mental and language retardation, hypernasal voice, sensory-motor neuropathy with autonomic involvement and signs of spastic paraparesis, alacrimia. gastroesophageal reflux, and achalasia. Molecular studies showed to mutations, the undescribed p.Tyr 19 Cys, and IVS14 +1 G.
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PMID:[Allgrove syndrome (triple A). Finding of a mutation not described in the AAAS gene]. 2282 7

Patients with severe biotinidase deficiency (BD), if untreated, may exhibit seizures, psychomotor delay, deafness, ataxia, visual pathology, conjunctivitis, alopecia, and dermatitis. Clinical features normally appear within the first months of life, between two and five. Seizures are one of the most common symptoms in these patients (55%), usually presented as generalized tonic-clonic, and improving within 24 h of biotin treatment. Treatment delay has been associated with irreversible neurological damage, mental retardation, ataxia, paraparesis, deafness, and epilepsy exceptionally.We report the case of a girl who was admitted at 2.5 months because of vomiting, failure to thrive, flexor spasms, dermatitis, and neurological depression for 1 month. BD was identified and was treated with biotin, stopping seizures and improving symptoms. Developmental delay, paraparesis, optic atrophy, and seizures during febrile illness were observed at follow-up. At the age of 8, she suffered hemigeneralized seizures despite appropriate biotin treatment, so levetiracetam was administered, and epilepsy was controlled. Organic acid measurement was performed to determine whether the child was receiving enough or no biotin.Even though BD is a rare condition, because the biotinidase screening is a reliable procedure and the disorder is readily treatable, the implementation of extended biotinidase screening will effectively help to prevent any acute and long-term neurological problems as well as the significant morbidity associated with untreated disease. In addition, neonatal screening and early treatment with biotin prevents severe neurological sequelae, such as epilepsy, which has not been thoroughly described in the literature.
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PMID:Epilepsy in biotinidase deficiency after biotin treatment. 2343 Aug 99

Argininemia is a rare hereditary disease due to a deficiency of hepatic arginase, which is the last enzyme of the urea cycle and hydrolyzes arginine to ornithine and urea. The onset of the disease is usually in childhood, and clinical manifestations include progressive spastic paraparesis and mental retardation. Liver involvement is less frequent and usually not as severe as observed in other UCDs. For this reason, and because usually there is a major neurological disease at diagnosis, patients with argininemia are rarely considered as candidates for OLT despite its capacity to replace the deficient enzyme by an active one. We report on long-term follow-up of two patients with argininemia. Patient 1 was diagnosed by the age of 20 months and despite appropriate conventional treatment progressed to spastic paraparesis with marked limp. OLT was performed at 10 years of age with normalization of plasmatic arginine levels and guanidino compounds. Ten years post-OLT, under free diet, there is no progression of neurological lesions. The second patient (previously reported by our group) was diagnosed at 2 months of age, during a neonatal cholestasis workup study. OLT was performed at the age of 7 years, due to liver cirrhosis with portal hypertension, in the absence of neurological lesions and an almost-normal brain MRI. After OLT, under free diet, there was normalization of plasmatic arginine levels and guanidino compounds. Twelve years post-OLT, she presents a normal neurological examination. We conclude that OLT prevents progressive neurological impairment in argininemia and should be considered when appropriate conventional treatment fails.
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PMID:Liver transplantation prevents progressive neurological impairment in argininemia. 2355 24

Mutations in MECP2 (MIM #312750), located on Xq28 and encoding a methyl CpG binding protein, are classically associated with Rett syndrome in female patients, with a lethal effect in hemizygous males. However, MECP2 mutations have already been reported in surviving males with severe neonatal-onset encephalopathy, or with X-linked intellectual disability associated with psychosis, pyramidal signs, parkinsonian features and macro-orchidism (PPM-X syndrome; MIM3 #300055). Here we report on the identification of the p.Ala140Val mutation in the MECP2 gene in 4 males and 3 females of a large Caucasian family affected with X-linked intellectual disability. Females present with mild cognitive impairment and speech difficulties. Males have moderate intellectual disability, impaired language development, friendly behavior, slowly progressive spastic paraparesis and dystonic movements of the hands. Two of them show microcephaly. The p.Ala140Val mutation is recurrent, as it was already described in 4 families with X-linked mental retardation and in three sporadic male patients with intellectual disability. We further delineate the phenotype associated with the p.Ala140Val mutation, illustrating a variable expressivity even within a given family, and we compare our patients with previous reported cases in the literature.
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PMID:Expanding phenotype of p.Ala140Val mutation in MECP2 in a 4 generation family with X-linked intellectual disability and spasticity. 2746 3

Bardet-Biedl syndrome (BBS) is a rare, autosomal-recessive, debilitating genetic disorder, which can present with multitudinous systemic clinical features including rod-cone dystrophy, polydactyly, Frohlich-like central obesity, mental retardation, hypogonadism, and renal anomalies. Diverse neuromuscular manifestations in patients afflicted by this heterogeneous disorder include ataxia, cervical, and thoracic canal stenoses, presenting as spastic quadriparesis and other gait disturbances. We report a young patient with BBS, who had presented with acute flaccid paraparesis due to severe primary lumbar canal stenosis. She underwent immediate lumbar decompression and discectomy following which she recovered significantly. Acute cauda equina syndrome due to primary lumbar canal stenosis has not been reported as a clinical feature of BBS previously.
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PMID:Acute flaccid paraparesis (cauda equina syndrome) in a patient with Bardet-Biedl syndrome. 2856 87

The interaction of multiple genetic factors, as opposed to monogenic inheritance, has been suspected to play a role in many diseases. This interaction has been described as an oligogenic inheritance model, which may be a useful tool in explaining certain clinical observations. The purpose of this study was to search for novel genetic defects among members of a family with traits that include mental retardation, short stature, osteopetrosis, calcification of basal ganglia, and thinning of the corpus callosum. In the index case (111-4), we identified four homozygous mutations: chromosome 8, intron2 (c.232+1G>A) at CA2 gene; chromosome 15, exon 32 (c.6100C>T) at the SPG11; chromosome 5, exon 11 (c.1015G>A) at the MCCC2; and chromosome 9, exon 9 (C.1193g>t) at the LARP gene. The mutations were confirmed by Sanger sequencing, and both parents were observed to be heterozygous for the four mutations. A moderately affected sister of the index case was homozygous for only three mutations in CA2, LARP, and Mccc2, while a nonaffected sister was heterozygous for three mutations in CA2, LARP, and MCCC2 and negative for SPG11. The clinical features of the two affected sisters can be explained distinctively by each homozygous mutation in an oligogenic pattern of inheritance. This family represents an example of an oligogenic pattern of inheritance of mental retardation, short stature, spastic paraparesis, and osteopetrosis.
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PMID:Potential oligogenic disease of mental retardation, short stature, spastic paraparesis, and osteopetrosis. 3051 Apr 38


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