James Jonathon Pitt

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OBJECTIVE Tandem mass spectrometry is widely applied to routine newborn screening but there are no long-term studies of outcome. We studied the clinical outcome at six years of age in Australia. METHODS In a cohort study, we analyzed the outcome at 6 years for patients detected by screening or by clinical diagnosis among >2 million infants born from 1994(More)
There are several rare syndromes combining wrinkled, redundant skin and neurological abnormalities. Although phenotypic overlap between conditions has suggested that some might be allelic to one another, the aetiology for many of them remains unknown. A consanguineous New Zealand Maori family has been characterised that segregates an autosomal recessive(More)
Liquid chromatography-mass spectrometry (LC-MS) is now a routine technique with the development of electrospray ionisation (ESI) providing a simple and robust interface. It can be applied to a wide range of biological molecules and the use of tandem MS and stable isotope internal standards allows highly sensitive and accurate assays to be developed although(More)
We describe biochemical and clinical features of 11 subjects (ages, 1.2-84 years, nine females and two males) with transient 5-oxoprolinuria (0.6-23.6 mol/mol of creatinine, reference range <0.07). A variety of conditions preceded the onset of acidosis, and all had taken acetaminophen (paracetamol), although in therapeutic amounts in most subjects.(More)
Two siblings with fatal Leigh disease had increased excretion of S-(2-carboxypropyl)cysteine and several other metabolites that are features of 3-hydroxyisobutyryl-CoA hydrolase (HIBCH) deficiency, a rare defect in the valine catabolic pathway associated with Leigh-like disease. However, this diagnosis was excluded by HIBCH sequencing and normal enzyme(More)
BACKGROUND Detection of abnormal metabolites in urine is important for the diagnosis of many inborn errors of metabolism (IEM). Rapid, comprehensive screening methods are needed. METHODS We used electrospray ionization tandem mass spectrometry in positive- and negative-ion modes to detect selected metabolites in urine. For positive-ion analysis, samples(More)
BACKGROUND Isolated excretion of 2-methylbutyrylglycine (2-MBG) is the hallmark of short/branched-chain acyl-CoA dehydrogenase deficiency (SBCADD), a recently identified defect in the proximal pathway of L-isoleucine oxidation. SBCADD might be underdiagnosed because detection and recognition of urine acylglycines is problematic. Excretion of(More)
Trimethylaminuria is an autosomal recessive disorder involving deficientN-oxidation of the dietary-derived amine trimethylamine (TMA). TMA, a volatile tertiary amine, accumulates and is excreted in urine of patients with deficient TMA oxidase activity. Treatment strategies for this condition are limited. We report a new stable-isotope dilution method for(More)
The determination of disulfide bonds is an important aspect of gaining a comprehensive understanding of the chemical structure of a protein. The basic strategy for obtaining this information involves the identification of disulfide-linked peptides in digests of proteins and the characterization of their half-cystinyl peptide constituents. Tools for(More)