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)

The 1p36 deletion syndrome is a newly delineated multiple congenital anomalies/mental retardation syndrome characterized by mental retardation, growth delay, epilepsy, congenital heart defects, characteristic facial appearance, and precocious puberty. We analyzed 11 patients by fluorescence in situ hybridization (FISH) using commercially available bacterial artificial chromosome and P1-derived artificial chromosome genomic clones to define the chromosomal deletion responsible for the 1p36 deletion syndrome. Cytogenetic investigation revealed two cases with a terminal deletion of 1p36. Nine patients had an apparently normal karyotype with standard G-bands by trypsin using Giemsa (GTG), but FISH screening with the highly polymorphic genetic marker D1Z2, which is mapped to 1p36.3 and contains an unusual reiterated 40-bp variable number tandem repeat, revealed a submicroscopic deletion. All patients had severe to profound mental retardation. Based on the University of California Santa Cruz Genome Browser, we constructed a deletion map and analyzed the relationship between neurological findings and chromosomal deletions for the 11 cases. Six cases had intractable epilepsy and three had no seizures. The common deletion interval was about 1 million base pairs (Mbp) located between RP11-82D16 and RP4-785P20 (Rho guanine exchange factor (GEF) 16). The severity of clinical symptoms correlates with the size of the deletion. This is demonstrated by the 3 patients with at least 8Mbp deletions that display profound mental retardation and congenital heart defects. Although haploinsufficiency of the potassium channel beta-subunit (KCNAB2) is thought to be responsible for intractable seizures in the 1p36 deletion syndrome, this was not the case for 3 of the 11 patients in this study. Further investigation of the 1p36 region is necessary to allow identification of genes responsible for the 1p36 deletion syndrome.
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PMID:Epilepsy and neurological findings in 11 individuals with 1p36 deletion syndrome. 1602 56

The 1p36 deletion syndrome is caused by submicroscopic deletion in the subtelomeric region of chromosome 1. Epilepsy is one of the most important features of the syndrome, in addition to the characteristic facial appearance, cardiac anomaly, dysphagia, deafness, mental retardation and growth delay. We identified three patients with this syndrome and assessed the features of complicated epilepsy. In all cases, epilepsy developed during infancy. The seizure types were mainly focal seizure and multiple seizure types including tonic seizure and tonic-clonic seizure. Interictal electroencephalogram showed focal abnormalities. Noticeably, two developed epileptic spasms and hypsarrhythmia in electroencephalogram, just after the administration of carbamazepine (CBZ). Including cases showing epileptic spasms, their epilepsy was easily tractable with anti-epileptic drugs, which could be withdrawn as they aged. All had deleted potassium channel beta subunit (KCNAB2) and gamma-aminobutyric acid A receptor delta (GABRD). CBZ may aggravate various epileptic syndromes, especially, those caused by GABA-A receptor gene mutation. Our cases may suggest the novel correspondence of GABA-A receptor-related epilepsy syndrome and exacerbation of epilepsy triggered by CBZ.
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PMID:[Effect of carbamazepine on epilepsy with 1p36 deletion syndrome]. 1763 87