Clinical indications for the investigation of porphyria: case examples and evolving laboratory approaches to its diagnosis in New Zealand

Patients with porphyria present in a diverse and unusual variety of ways and most clinicians will see only a few cases, if any, during their professional lives. Porphyria may present (1) with acute symptoms, which may be abdominal pain, neurological or psychiatric; (2) with skin rash or photosensitivity; or (3) with a putative family history. Screening for latent porphyria has been greatly facilitated by fluorescence emission scanning of plasma and by mutational analysis. Our reference laboratory has recently diagnosed several cases of the less common types of porphyria, which we postulate is due to the availability of these methods and to the changing population of New Zealand. Accurate screening and diagnosis of porphyria is important, as an acute porphyric attack is life-threatening and preventable. Retrospective diagnosis may be difficult.

Biochemical and genetic characterization of four cases of hereditary coproporphyria in Spain

We report a biochemical and genetic characterization of four cases of hereditary coproporphyria (HCP) in Spain. All patients showed a typical HCP porphyrin excretion pattern with a high concentration of coproporphyrins in feces and inverted I:III isomer ratio. The porphyrin precursors in urine were found elevated in two patients who showed acute symptoms. The analysis of the CPO gene showed that three cases harboured novel mutations: V135A (404T>C; exon 1); L214R (641T>G; exon 2); and P249R (746C>G; exon 3) and in the fourth, a previously described R426X mutation in exon 6.

Identification of monovinyl tripropionic acid porphyrins and metabolites from faeces of patients with hereditary coproporphyria by high-performance liquid chromatography/electrospray ionization quadrupole time-of-flight tandem mass spectrometry

Harderoporphyrin (2-vinyl-4,6,7-tripropionic acid porphyrin) and its metabolites in faeces of patients with hereditary coproporphyria (HCP) have been separated and characterized by high-performance liquid chromatography/electrospray ionization quadrupole time-of-flight tandem mass spectrometry (HPLC/ESI-Q-TOFMS/MS). The metabolites identified were 2-ethyl-4,6,7-tripropionic acid porphyrin, 2-hydro-4,6,7-tripropionic acid porphyrin, 2-methoxyethyl-4,6,7-tripropionic acid porphyrin and 2-acetyl-4,6,7-tripropionic acid porphyrin. Isomers of harderoporphyrin derived from isomerization of harderoporphyrinogen were also detected.