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)

We describe two patients affected by Barth syndrome. Their symptoms became manifest on respectively the third and first day of their lives. Clinical presentation included poor sucking, lethargy, hypotonia, hypothermia and cardiomyopathy. Laboratory findings such as hypoglycaemia, metabolic acidosis, elevated transaminases, hyperlactacidaemia and mild hyperammonaemia pointed to an inborn error of energy metabolism with possible mitochondrial involvement. Molecular analysis of the TAZ (G4.5) gene showed the c.877G > A mutation leading to the G197R amino acid substitution in patient 1, and the new splice donor c.829 + 1G > A genetic lesion in patient 2.
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PMID:Barth syndrome presenting with acute metabolic decompensation in the neonatal period. 1690 70

Barth syndrome presents in infancy with hypotonia, dilated cardiomyopathy, and neutropenia. We report a patient whose family history included two males who had died suddenly at the age of 15 days and 2 years, respectively. The index case presented with acute metabolic decompensation at 13 days of age. Within 8 h of presenting with metabolic acidosis (pH 7.13), lactic acidemia (18.5 mmol/l), hyperammonemia (375 microg/dl), hypoglycemia (25 mg/dl), and coagulopathy, the patient developed respiratory failure and required intubation. The diagnosis was established by the presence of left ventricular noncompaction and molecular analysis (c.C153G or Y51X mutation of the TAZ gene). The gene product, taffazin, is a homologue of the glycerolipid transferases involved in the phospholipid metabolism as tetralinoleoyl-cardiolipin, a component of the mitochondrial inner membrane. In conclusion, mutations in taffazin impair mitochondrial respiratory chain complexes, which may results in the acute metabolic decompensation and sudden death; cardiac transplantation is the only possibility at the present time.
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PMID:Acute metabolic decompensation and sudden death in Barth syndrome: report of a family and a literature review. 1784 86

Barth syndrome (BTHS) is an X-linked inborn error of metabolism which affects males. The main manifestations are cardiomyopathy, myopathy, hypotonia, growth delay, intermittent neutropenia and 3-methylglutaconic aciduria. Diagnosis is confirmed by mutational analysis of the TAZ gene and biochemical dosage of the monolysocardiolipin/tetralinoleoyl cardiolipin (MLCL:L4-CL) ratio. We report a 6-year-old boy who presented with severe hypoglycemia, lactic acidosis and severe dilated cardiomyopathy soon after birth. The MLCL:L4-CL ratio confirmed BTHS (3.90 on patient's fibroblast, normal: 0-0.3). Subsequent sequencing of the TAZ gene revealed only the new synonymous variant NM_000116.3 (TAZ):c.348C>T p.(Gly116Gly), which did not appear to affect the protein sequence. In silico prediction analysis suggested the new c.348C>T nucleotide change could alter the TAZ mRNA splicing processing. We analyzed TAZ mRNAs in the patient's fibroblasts and found an abnormal skipping of 24 bases (NM_000116.3:c.346_371), with the consequent ablation of 8 amino acid residues in the tafazzin protein (NP_000107.1:p.Lys117_Gly124del). Molecular analysis of at risk female family members identified the patient's sister and mother as heterozygous carriers. Apparently harmless synonymous variants in the TAZ gene can damage gene expression. Such findings widen our knowledge of molecular heterogeneity in BTHS.
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PMID:When silence is noise: infantile-onset Barth syndrome caused by a synonymous substitution affecting TAZ gene transcription. 2685 23