Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0009676 (confusion)
 21,692 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Biotin-responsive basal ganglia disease (BBGD) is a recessive disorder with childhood onset that presents as a subacute encephalopathy, with confusion, dysarthria, and dysphagia, and that progresses to severe cogwheel rigidity, dystonia, quadriparesis, and eventual death, if left untreated. BBGD symptoms disappear within a few days with the administration of high doses of biotin (5-10 mg/kg/d). On brain magnetic resonance imaging examination, patients display central bilateral necrosis in the head of the caudate, with complete or partial involvement of the putamen. All patients diagnosed to date are of Saudi, Syrian, or Yemeni ancestry, and all have consanguineous parents. Using linkage analysis in four families, we mapped the genetic defect near marker D2S2158 in 2q36.3 (LOD=5.9; theta=0.0) to a minimum candidate region (approximately 2 Mb) between D2S2354 and D2S1256, on the basis of complete homozygosity. In this segment, each family displayed one of two different missense mutations that altered the coding sequence of SLC19A3, the gene for a transporter related to the reduced-folate (encoded by SLC19A1) and thiamin (encoded by SLC19A2) transporters.
 ...
PMID:Biotin-responsive basal ganglia disease maps to 2q36.3 and is due to mutations in SLC19A3. 1587 Nov 39

Wernicke's encephalopathy is a syndrome characterized by ataxia, ophthalmoplegia, and confusion with thiamine deficiency. We reported on two Japanese brothers with a newly discovered recessively inherited syndrome similar to Wernicke's encephalopathy that developed in the second decade of life; this syndrome was manifested clinically as thiamine-responsive diplopia, ataxia and confusion without serum thiamine deficiency. The patients had complex partial seizure. The administration of high-dose thiamine improved these symptoms. MRI of the brain showed high-intensity signals in the bilateral medial thalamus and periaqueductal region on fluid-attenuated inversion recovery images; these signals were characteristic of findings in Wernicke's encephalopathy. There was no history of chronic alcoholism. The clinical and images features resembling Wernicke's encephalopathy in these patients suggested that the syndrome was caused by a genetic disorder of thiamine metabolism. Genomic analysis of SLC10A3 encoding human thiamine transporter 2 revealed that the patients were compound heterozygotes for the K44E and E320Q mutations. Gene-expression analyses of mammalian culture cells showed that intracellular thiamine uptake activities were decreased significantly. High expression of SLC19A3 RNA in the thalamus may explain the selective thalamic lesions on MRI. The identification of this syndrome proves insight into the thiamine metabolism associated with Wernicke's encephalopathy in humans.
 ...
PMID:[Familial Wernicke's-like encephalopathy]. 2192 71

Wernicke's encephalopathy is a triad of ophthalmoplegia, ataxia and confusion seen in alcoholics with dietary vitamin B1 (thiamine) deficiency. A rare genetic defect of thiamine transporter-2 may lead to similar clinical features, biotin-thiamine responsive basal ganglia disease (BTBGD). A 15-year-old girl developed rapid onset ptosis and ophthalmoplegia evolving into a subacute encephalopathy. Neuroimaging demonstrated symmetrical basal ganglia and mid-brain lesions reminiscent of Leigh's subacute necrotising encephalomyelopathy. Oral biotin and thiamine were started, and symptoms improved dramatically the next day. The therapeutic response suggested SLC19A3, encoding thiamine transporter-2, as a strong candidate gene and Sanger sequencing revealed a novel homozygous c.517A>G;p.Asn173Asp mutation, which segregated with disease within the family. BTBGD is a potentially treatable neurological disorder and should be considered in the differential diagnosis of Leigh syndrome and Wernicke's encephalopathy. Since delayed treatment results in permanent neurological dysfunction or death, prompt diagnosis and early initiation of biotin and thiamine therapy are essential.
...
PMID:Treatable Leigh-like encephalopathy presenting in adolescence. 2409 34

Mutations in the gene SLC19A3 result in thiamine metabolism dysfunction syndrome 2, also known as biotin-thiamine-responsive basal ganglia disease (BTBGD). This neurometabolic disease typically presents in early childhood with progressive neurodegeneration, including confusion, seizures, and dysphagia, advancing to coma and death. Treatment is possible via supplement of biotin and/or thiamine, with early treatment resulting in significant lifelong improvements. Here we report two siblings who received a refined diagnosis of BTBGD following whole-genome sequencing. Both children inherited compound heterozygous mutations from unaffected parents; a missense single-nucleotide variant (p.G23V) in the first transmembrane domain of the protein, and a 4808-bp deletion in exon 1 encompassing the 5' UTR and minimal promoter region. This deletion is the smallest promoter deletion reported to date, further defining the minimal promoter region of SLC19A3 Unfortunately, one of the siblings died prior to diagnosis, but the other is showing significant improvement after commencement of therapy. This case demonstrates the power of whole-genome sequencing for the identification of structural variants and subsequent diagnosis of rare neurodevelopmental disorders.
 ...
PMID:Compound heterozygous SLC19A3 mutations further refine the critical promoter region for biotin-thiamine-responsive basal ganglia disease. 2869 12