Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026827 (hypotonia)
 5,860 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epilepsies associated with inborn errors of metabolism (IEM) represent a major challenge. Seizures rarely dominate the clinical presentation, which is more frequently associated with other neurological symptoms, such as hypotonia and/or cognitive disturbances. Although epilepsy in IEM can be classified in various ways according to pathogenesis, age of onset, or electroclinical presentation, the most pragmatic approach is determined by whether they are accessible to specific treatment or not. The main potentially treatable causes comprise vitamin B6 (pyridoxine deficiency), biotine, and GLUT1 deficiency (GLUT1DS) syndromes. Folinic acid-dependent seizures are allelic with pyridoxine dependency. Incompletely treatable IEMs include pyridoxal phosphate, serine, and creatine deficiencies. The main IEMs that present with epilepsy but offer no specific treatment are nonketotic hyperglycinemia, mitochondrial disorders, sulfite oxidase deficiency, ceroid-lipofuscinosis, Menkes disease, and peroxisomal disorders.
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PMID:Epilepsy in inborn errors of metabolism. 2362 1

We report the case of a 10-year-old Spanish girl with mutations in NADK2 Prenatal central nervous system abnormalities showed ventriculomegaly, colpocephaly, and hypoplasia of the corpus callosum. At birth, axial hypotonia, uncoordinated movements, microcephaly, and generalized cerebellar atrophy were detected. Metabolic investigations revealed high lysine, lactate, and pipecolic acid levels in blood and cerebrospinal fluid. Pyruvate carboxylase and pyruvate dehydrogenase activity in fibroblasts were normal. Beginning at birth she received biotin, thiamine, and carnitine supplementation. A lysine-restricted diet was started when she was 1 month old. Because pipecolic acid was high, pyridoxine was added to treatment. At 3 years old, astatic myoclonic epilepsy appeared, with no response to levetiracetam. We switched pyridoxine to pyridoxal phosphate, with electroclinical improvement. Because the activity of mitochondrial respiratory chain complexes III and IV was slightly low in muscle, other cofactors such as ubidecarenone, idebenone, vitamin E, and creatine were added to the treatment. At 8 years old, plasma acylcarnitine testing was performed, and high levels of 2-trans, 4-cis-decadienoylcarnitine were found. Whole exome sequencing identified a homozygous splice site mutation in NADK2 (c.956+6T>C; p.Trp319Cysfs*21). This substitution generates exon skipping, leading to a truncated protein. In fact, NADK2 messenger RNA and the corresponding protein were almost absent. Now, at 10 years of age she presents with ataxia and incoordination. She has oromotor dysphasia but is able to understand fluid language and is a very friendly girl. We hypothesize that the patient's clinical improvement could be due to her lysine-restricted diet together with cofactors and pyridoxal phosphate administration.
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PMID:Lysine Restriction and Pyridoxal Phosphate Administration in a NADK2 Patient. 2794 Jul 55

The pathophysiology of the neuromuscular manifestations of hypophosphatasia (HPP) remains unknown. Pyridoxine-sensitive seizures characterize severe forms of infantile HPP. Young children and infants affected with severe forms of HPP, but also adults often present with myopathy characterized by hypotonia or muscle weakness. Chronic pain, of unclear mechanism is also often present. Tissue-non-specific alkaline phosphatase (Alkaline Phosphatase-Liver/Bone/Kidney [ALPL]) is expressed in brain neuronal cell and in muscle cells during development and adulthood. The knockout of the ALPL impacts neuronal functions in animal models. This may occur through metabolic anomalies involving gamma-aminobutyric acid (GABA) and other neurotransmitters via the metabolism of pyridoxal phosphate (vitamin B6) and phosphoethanolamine. In this context, a greater understanding of the neuromuscular pathophysiology of HPP is critical to assess the potential impact of new therapies.
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PMID:Neuromuscular features of hypophosphatasia. 2940 39