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

Alternating hemiplegia of childhood (AHC) is a rare disorder mainly characterised by attacks of hemiplegia and mental retardation. AHC has often been associated with migraine. Previously, we have excluded the involvement of the familial hemiplegic migraine (FHM) CACNA1A gene in four patients with AHC. A second gene for FHM was discovered recently: the ATP1A2 gene on chromosome 1q23, coding for the alpha 2 subunit of Na+,K+-ATPase. We performed a mutation analysis of the ATP1A2 gene in six patients, using direct sequencing, but found no mutations in any of the 23 exons. Other cerebral ion channel genes remain candidate genes for AHC.
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PMID:Alternating hemiplegia of childhood: no mutations in the second familial hemiplegic migraine gene ATP1A2. 1553 63

Alternating hemiplegia of childhood (AHC) is a severe brain disorder, mainly characterised by episodes of hemiplegia, progressive mental retardation, and other severe paroxysmal and permanent neurological symptoms. Clinically and genetically, there is some overlap with sporadic (SHM) and familial (FHM) hemiplegic migraine, a severe monogenic subtype of migraine. Although no mutations were detected in the FHM1 CACNA1A and FHM2 ATP1A2 genes in sporadic AHC patients, a mutation was found in the FHM2 ATP1A2 gene in a family with AHC. Recently, a missense mutation was found in the SLC1A3 gene that encodes the glutamate transporter EAAT1, in a patient with alternating hemiplegia, episodic ataxia, seizures, and headache. Because of the remarkable clinical similarities and the potential role of glutamate in AHC, we analysed six sporadic patients with AHC for mutations in the SLC1A3 gene. No mutations were found. The SLC1A3 EAAT1 glutamate transporter gene does not seem to be involved in the pathogenesis of AHC.
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PMID:Alternating hemiplegia of childhood: no mutations in the glutamate transporter EAAT1. 1723 10

Familial hemiplegic migraine (FHM) is a severe dominant form of migraine with aura associated with transient hemiparesis. Several other neurological signs and symptoms can be associated with FHM such as cerebellar abnormalities, cerebral edema and coma after minor head trauma, epileptic seizures and mental retardation. The sporadic form of hemiplegic migraine named SHM, presents with identical clinical symptoms. Here we report a case of a young hemiplegic migraine patient, 11 years old, who had the first hemiplegic attack at the age of 10 years. This patient has a clinical history of epileptic seizures in the childhood successfully controlled with drug therapy. No familiarity for any type of migraine or seizures can be observed within the paternal or maternal line. The patient who can therefore be considered a sporadic case, carries a novel de novo nonsense mutation p.Tyr1009X in the ATP1A2 gene (FHM2), leading to a truncated alpha-2 subunit of the Na+/K+-ATPase pump thus lacking the last 11 amino acids. The novel mutation identified confirms the role of FHM2 gene in forms of hemiplegic migraine associated with epilepsy with both familial and sporadic occurrence, and expands the spectrum of mutations related to these forms of the disease.
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PMID:A novel de novo nonsense mutation in ATP1A2 associated with sporadic hemiplegic migraine and epileptic seizures. 1864 8

To determine the phenotypic significance of copy number changes (CNCs) in the human genome, we performed genome-wide segmental aneuploidy profiling by BAC-based array-CGH of 278 unrelated patients with multiple congenital abnormalities and mental retardation (MCAMR) and in 48 unaffected family members. In 20 patients, we found de novo CNCs composed of multiple consecutive probes. Of the 125 probes making up these probably pathogenic CNCs, 14 were also found as single CNCs in other patients and 5 in healthy individuals. Thus, these CNCs are not by themselves pathogenic. Almost one out of five patients and almost one out of six healthy individuals in our study cohort carried a gain or a loss for any one of the recently discovered microdeletion/microduplication loci, whereas seven patients and one healthy individual showed losses or gains for at least two different loci. The pathogenic burden resulting from these CNCs may be limited as they were found with similar frequencies among patients and healthy individuals (P=0.165; Fischer's exact test), and several individuals showed CNCs at multiple loci. CNCs occurring specifically in our study cohort were enriched for components of the glutamate receptor family (GRIA2, GRIA4, GRIK2 and GRIK4) and genes encoding proteins involved in guiding cell localization during development (ATP1A2, GIRK3, GRIA2, KCNJ3, KCNJ10, KCNK17 and KCNK5). This indicates that disease cohort-specific compilations of CNCs may aid in identifying loci, genes and biological processes that contribute to the phenotype of patients.
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PMID:Recurrent copy number changes in mentally retarded children harbour genes involved in cellular localization and the glutamate receptor complex. 1962 14

Hemiplegic migraine (HM) is a rare and severe subtype of migraine with aura, characterized by some degree of hemiparesis and other aura symptoms. Mutations in three genes (CACNA1A, ATP1A2 and SCN1A) have been detected in familial and, more rarely, in sporadic cases. The disease can be complicated by permanent neurological deficits, the most frequent one being a cerebellar syndrome; in addition, mental retardation has been recognized as part of the phenotypic spectrum. Here, we report a Caucasian male with a novel CACNA1A mutation and an unusual clinical phenotype: the patient, who had had a history of only two HM attacks, sought medical advice at age 49 primarily because of increasing cognitive decline accompanied by cerebellar dysfunction. While common neurodegenerative causes were excluded, neuropsychological evaluation revealed a distinct profile of deficits of a subcortico-prefrontal type as previously reported in patients with cerebellar dysfunction. This suggests a possible causal link between cerebellar and cognitive disturbances in this patient; in addition to these pathophysiological aspects, we review of the role of the cerebellum in cognition.
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PMID:A novel mutation in CACNA1A associated with hemiplegic migraine, cerebellar dysfunction and late-onset cognitive decline. 2103 46

Hemiplegic migraine (HM) is a rare and severe subtype of autosomal dominant migraine, characterized by a complex aura including some degree of motor weakness. Mutations in four genes (CACNA1A, ATP1A2, SCN1A and PRRT2) have been detected in familial and in sporadic cases. This genetically and clinically heterogeneous disorder is often accompanied by permanent ataxia, epileptic seizures, mental retardation, and chronic progressive cerebellar atrophy. Here we report a mutation screening in the CACNA1A and ATP1A2 genes in 18 patients with HM. Furthermore, intragenic copy number variant (CNV) analysis was performed in CACNA1A using quantitative approaches. We identified four previously described missense CACNA1A mutations (p.Ser218Leu, p.Thr501Met, p.Arg583Gln, and p.Thr666Met) and two missense changes in the ATP1A2 gene, the previously described p.Ala606Thr and the novel variant p.Glu825Lys. No structural variants were found. This genetic screening allowed the identification of more than 30% of the disease alleles, all present in a heterozygous state. Functional consequences of the CACNA1A-p.Thr501Met mutation, previously described only in association with episodic ataxia, and ATP1A2-p.Glu825Lys, were investigated by means of electrophysiological studies, cell viability assays or Western blot analysis. Our data suggest that both these variants are disease-causing.
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PMID:Screening of CACNA1A and ATP1A2 genes in hemiplegic migraine: clinical, genetic, and functional studies. 2449 17

Mutations in the ATP1A2 gene cause familial hemiplegic migraine type 2, alternating hemiplegia of childhood, and cerebellar function deficits, epilepsy, and mental retardation. These symptoms are likely related to glutamatergic hyperexcitability. Our patient is a 12-year-old boy with a history of complex partial seizures, attention-deficit/hyperactivity disorder, and fine motor difficulty. During early childhood, he had episodes of a self-resolving right-sided hemiparesis and focal epilepsy. His seizures did not respond to several antiepileptic medications but stopped after he received valproate. His intermittent episodes of hemiplegia persisted. Additionally, he had pronounced bilateral fine motor impairment and significant executive deficits that gradually worsened. The whole exome sequencing revealed a de novo missense mutation in the ATP1A2 gene and a maternally inherited POLG gene mutation of unknown clinical significance. We hypothesized that glutamatergic excitotoxicity due to the ATP1A2 mutation contributed to the pathogenesis of our patient's condition. He was started on N-methyl-D-aspartate receptor antagonists (memantine and dextromethorphan), as well as coenzyme Q10 One year later, he showed significant improvement in sustained attention, learning efficiency, general cognitive efficiency, and fine motor dexterity. We postulate that N-methyl-D-aspartate receptor antagonists were effective for behavioral, cognitive, and cerebellar symptoms in our patient with ATP1A2 gene mutation.
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PMID:Clinical Benefit of NMDA Receptor Antagonists in a Patient With ATP1A2 Gene Mutation. 2961 Jan 57

Hemiplegic migraine (HM) is a rare subtype of migraine with aura in which attacks include transient motor weakness or hemiparesis that can last several days. HM is linked to mutations in three different genes, CACNA1A, ATP1A2 and SCN1A, which encode for ion transporters. The clinical spectrum includes atypical symptoms such as impaired consciousness, epileptic seizures, permanent cerebellar ataxia or mental retardation. We describe a novel mutation found in the ATP1A2 gene in a patient with late-onset HM. His attacks were characterised by motor weakness associated with altered mental status, diplopia and ataxia. He also showed up MRI abnormalities and incomplete response to prophylactic therapy with verapamil. Late-onset HM should be considered among the possible causes of focal neurological deficits even in older patients with cerebrovascular risk factors when a stroke appears to be more likely.
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PMID:Novel missense mutation in the ATP1A2 gene associated with atypical sporapedic hemiplegic migraine. 3158 57