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OTC Deficiency (otc + deficiency)

Distribution by Scientific Domains

Medical Sciences	60%

Selected Abstracts

H intragenic polymorphisms and haplotype analysis in the ornithine transcarbamylase (OTC) gene and their relevance for tracking the inheritance of OTC deficiency,,

HUMAN MUTATION, Issue 5 2002
Consuelo Climent
Abstract The "private" nature of most mutations causing ornithine transcarbamylase (OTC) deficiency makes mutation identification in the patients difficult. Further, the PCR-amplification technology generally used for the genetic diagnosis of the deficiency misses large deletions in carrier females. Intragenic OTC polymorphisms may allow detection of these deletions and may represent an alternative to mutation detection for prenatal diagnosis and carrier identification in families with a history of inherited OTC deficiency. A new highly informative polymorphism (allele frequencies, 0.66/0.34) in intron 3 of the OTC gene (IVS3-39_40insT) is reported here, and allelic frequencies of 16 additional intragenic OTC polymorphisms are determined in 133-35 (average per polymorphism, 72) unrelated chromosomes. In addition to the novel polymorphism, only three of the studied polymorphisms (Lys46Arg, allelic frequency 0.68/0.32; IVS3-8A>T, 0.34/0.66; Gln270Arg, 0.97/0.03) are confirmed to be informative. These provide, together with another reported polymorphism (IVS4-7A>G; reported allelic frequency 0.71/0.29; Plante and Tuchman, 1998), a set of highly valuable markers of the OTC gene. Nevertheless, the combined informativity of the studied polymorphisms is limited by their distribution in only four haplotypes with one of them predominating (65% of the sampled chromosomes). Although this haplotype composition may be restricted to the Iberian peninsula (the origin of the samples), more informative polymorphisms are required to increase the diagnostic potential and, particularly, to identify large deletions affecting OTC gene exons 5-10, where only one polymorphism of weak diagnostic value is known. © 2002 Wiley-Liss, Inc. [source]

Ornithine transcarbamylase deficiency: A possible risk factor for thrombosis,,

PEDIATRIC BLOOD & CANCER, Issue 1 2009
Lakshmi Venkateswaran MD
Abstract Ornithine transcarbamylase (OTC) deficiency is the most common urea cycle defect. Thromboembolic complications have not heretofore been linked with this diagnosis. We describe four patients with neonatal-onset OTC deficiency who developed vascular thromboses. One patient had arterial thrombosis; the rest developed venous thromboses. Multiple pro-thrombotic risk factors were identified. Low plasma arginine levels were observed in all patients at the time of thrombosis. Arginine deficiency and the resultant nitric oxide insufficiency may contribute to thrombotic risk. Careful normalization of plasma arginine and citrulline levels and increased surveillance for thrombotic complications should be considered in patients with OTC deficiency. Pediatr Blood Cancer 2009;53:100,102. © 2009 Wiley-Liss, Inc. [source]

Acute hyperammonaemic encephalopathy in a female newborn caused by a novel, de novo mutation in the ornithine transcarbamylase gene

ACTA PAEDIATRICA, Issue 5 2004
D Valik
A full-term female offspring of a first and uneventful pregnancy presented at 60 h of life with irritability, tachypnea and respiratory alkalosis progressing to deep coma with clinically dominant circulatory failure, tachycardia and hypotension. Diagnosis of ornithine transcarbamylase (OTC) deficiency was made on the basis of hyperammonaemia, hypocitrullinaemia and extreme hyper-excretion of orotic acid. The baby was treated with peritoneal dialysis, arginine hydrochloride and adequate energy supply. DNA analysis revealed an as of yet unidentified missense mutation in the 6th exon of the OTC gene, resulting in a change of lysine to glutamine at position 210 (K210Q). Her parents were not found to carry this mutation, implying that this mutation may have occurred either de novo in the patient or in a parental germ cell. Conclusion: An acute neonatal form of OTC deficiency should be considered in the differential diagnosis of coma in female newborns. [source]