Yeungnam Univ J Med.  2007 Dec;24(2):322-328.

A Case of Molecular Diagnosis of Ornithine Transcarbamylase Deficiency

• Lee ES

Abstract

Ornithine transcarbamylase (OTC) deficiency is the most common inborn error of urea cycle metabolism; it is inherited in an X-linked manner. The OTC catalyzes the third step of the urea cycle, the conversion of ornithine and carbamyl phosphate to citrulline. Deficiency of OTC leads to the accumulation of ammonia, causing neurological deficits. In most affected hemizygote males, OTC deficiency manifests as hyperammonemic coma that often leads to death in the newborn period, and those who recover from the coma may be neurologically impaired due to the sequelae of the hyperammonemic encephalopathy. In some, late-onset manifestations develop. We report a male neonate with early onset OT deficiency that had apnea and was comatous. On mutation analysis using DNA sequencing after polymerase chain reaction (PCR) amplification of the 10 exons, deletions of 10 bases in codon 285, causing a frame shift was detected in exon 8. The mother and a sister were diagnosed as female carriers. Therefore, genetic counseling and the risk assessment could be provided to the family.

Keyword

Ornithine transcarbamylase deficiency; Heterozygote male; Mutation analysis

MeSH Terms

Ammonia
Apnea
Carbamyl Phosphate
Citrulline
Codon
Coma
Diagnosis*
Exons
Female
Genetic Counseling
Hemizygote
Humans
Infant, Newborn
Male
Metabolism
Mothers
Ornithine Carbamoyltransferase Deficiency Disease*
Ornithine Carbamoyltransferase*
Ornithine*
Polymerase Chain Reaction
Risk Assessment
Sequence Analysis, DNA
Siblings
Urea
Ammonia
Carbamyl Phosphate
Citrulline
Codon
Ornithine
Ornithine Carbamoyltransferase
Urea