ABSTRACT
El síndrome de deficiencia del transportador de glucosa tipo 1 es una enfermedad de causa genética, que involucra el gen SLC2A1. En general, se presenta durante los primeros años de vida con retraso en la adquisición de pautas madurativas, epilepsia farmacorresistente y desórdenes del movimiento. La clínica y la disminución de glucosa en líquido cefalorraquídeo permiten sospechar el diagnóstico, el cual debe ser confirmado mediante el estudio molecular del gen SLC2A1. Debido a que se trata de una enfermedad poco frecuente y de expresión clínica variable, el diagnóstico precoz suele representar un desafío para los equipos de salud. Este es importante, ya que la implementación de la terapia cetogénica logra controlar las manifestaciones clínicas y mejora el pronóstico a largo plazo. Presentamos una revisión sobre el déficit del transportador de glucosa tipo 1, que abarca sus características clínicas, bioquímicas, moleculares y terapéuticas.
Glucose transporter type 1 deficiency with a typical onset is a genetic disorder associated with the SLC2A1 gene. Usually appears during the first years of life with severe developmental delay, drugresistant epilepsy, and movement disorders. Diagnosis is suspected based on clinical manifestations and a low glucose level in cerebrospinal fluid, and should be confirmed by the molecular genetic study of the SLC2A1 gene. As it is a rare disease with variable clinical expression, early diagnosis is often challenging for the healthcare team. Nevertheless, this is important because early implementation of ketogenic therapy will lead to control of the clinical manifestations and a better long-term prognosis. Here we review the glucose transporter type 1 deficiency syndrome focusing on its clinical, biochemical, molecular, and therapeutic characteristics.
Subject(s)
Humans , Carbohydrate Metabolism, Inborn Errors/diagnosis , Carbohydrate Metabolism, Inborn Errors/genetics , Carbohydrate Metabolism, Inborn Errors/therapy , Monosaccharide Transport Proteins/genetics , Epilepsy/diagnosis , Epilepsy/genetics , MutationABSTRACT
El síndrome de deficiencia del transportador de glucosa cerebral de tipo 1 es una enfermedad neurometabólica rara en pediatría. Existe un fenotípico clásico (85 %) y otro no clásico (15 %). Ambos fenotipos se asocian con hipoglucorraquia. Se identifican múltiples mutaciones en el gen SLC2A1. El tratamiento es la terapia cetogénica. Se presenta un varón que comenzó a los cuatro años con hemicorea y hemidistonía medicado con anticonvulsivantes sin respuesta clínica, por lo que consultó nuevamente a los seis años. Con sospecha diagnóstica de síndrome de déficit de glut-1 atípico se realizó punción lumbar; el diagnóstico se confirmó por la presencia de hipoglucorraquia. Inmediatamente después de iniciar la dieta cetogénica, el paciente no presentó más movimientos anormales durante los siguientes 8 años hasta la actualidad, ya cumplidos los 14 años.
Glucose transporter type 1 deficiency syndrome is a rare pediatric neurometabolic disorder. There are two phenotypes: the classical phenotype (85%) and the non-classic (15%). Both phenotypes are associated with hypoglycorrhachia. Multiple mutations are described in the SCL2A1 gene. The treatment is the ketogenic diet. We report a case of a four-year-old male patient who started with hemichorea and hemidystonia and was medicated with drugs for seizures without clinical response, that's why his parents made another pediatric consultation at his six-year-old. With the suggestive clinical findings of glucose transporter type 1 deficiency syndrome the lumbar puncture was made confirming the diagnosis. Immediately after starting the ketogenic diet the patient stopped making abnormal movements up to the moment when he is fourteen years old, eight years after.
Subject(s)
Humans , Male , Adolescent , Carbohydrate Metabolism, Inborn Errors/complications , Carbohydrate Metabolism, Inborn Errors/diagnosis , Carbohydrate Metabolism, Inborn Errors/genetics , Diet, Ketogenic , Monosaccharide Transport Proteins/deficiency , Monosaccharide Transport Proteins/genetics , Glucose Transporter Type 1ABSTRACT
OBJECTIVE@#To explore the genetic basis for a child with ocular anomaly, microcephaly, growth retardation and intrauterine growth restriction.@*METHODS@#The patient underwent ophthalmologic examinations including anterior segment photography, fundus color photography, and fundus fluorescein angiography. The patient and her parents were subjected to whole exome sequencing. Candidate variants were verified by Sanger sequencing and bioinformatic analysis.@*RESULTS@#The patient was found to have bilateral persistent pupillary membrane and coloboma of inferior iris, in addition with macular dysplasia and radial pigmentation near the hemal arch of the temporal retina. She was found to have carried compound heterozygous missense variants of the PHGDH gene, namely c.196G>A and c.1177G>A, which were respectively inherited from her father and mother. Bioinformatic analysis suggested both variants to be pathogenic.@*CONCLUSION@#The patient was diagnosed with phosphoglycerate dehydrogenase deficiency. Above finding has enriched the phenotypic spectrum of the disease with ocular manifestations.
Subject(s)
Child , Female , Humans , Carbohydrate Metabolism, Inborn Errors/genetics , Coloboma , Microcephaly/genetics , Mutation , Phenotype , Phosphoglycerate Dehydrogenase/genetics , Psychomotor Disorders/genetics , Seizures/genetics , Exome SequencingABSTRACT
The glucose transporter type 1 deficiency syndrome (GLUT-1 SD) (OMIM 606777) is an inborn error of metabolism of brain glucose transport. The characteristic clinical manifestations are seizures, hypotonia, developmental delay, microcephaly and hypoglycorrhachia. We report a girl with normal weight and height at birth. At 6 weeks of age she started with convulsions reaching up to 20 myoclonic seizures a day. She was treated with valproate, phenobarbital and carbamazepine without response. Blood analysis including aminoacids and acylcarnitines were all normal. The brain MRI showed frontal atrophy with an increased subarachnoidal space and Electroencephalography was abnormal. Blood glucose was 84 mg/dl and spinal fluid glucose 26 mg/dl with a ratio of 0.31 (Normal Ratio >0.65+00.1). These results suggested the diagnosis of GLUT-1 SD, and was confirmed with erythrocyte glucose uptake of 44 percent (Normal range 80-100 percent). A molecular study found the mutation 969del, C971T in exon 6 of the gene Glut-1. Treatment with a ketogenic diet was started immediately and after 7 days with this diet seizures ceased. Anticonvulsants were progressively suspended. At present, the patient is 6 years old, she continues on a ketogenic diet and supplements with L-carnitine, lipoic acid, vitamins and minerals. Growth and development are normal with an intelligence quotient of 103. It is concluded that it is necessary to include GLUT-1 SD in the differential diagnosis of children with early seizures that are non responsive to pharmacological treatment.