Erythropoietic protoporphyria in Denmark: Demographic, biochemical and genetic characteristics

M. S. Skovmose, P. Jepsen, E. J. Erlandsen, P. R. Mortensen, M. Østergaard, A. Brock

Publikation: Konferencebidrag uden forlag/tidsskriftKonferenceabstrakt til konferenceForskningpeer review

Abstrakt

Erythropoietic protoporphyria (EPP) is an inherited cutaneous porphyria caused by partial deficiency of the ferrochelatase gene (FECH), leading to accumulation of protoporphyrin IX (PPIX) in erythrocytes, skin and liver, and acute photosensitivity. Less frequently, a mutation in the delta-aminolaevulinate synthase 2 (ALAS2) gene, may lead to EPP. The aim of the study was to investigate the demographic, biochemical and genetic features of patients with EPP in Denmark during the period 2000-2010.
A laboratory database with all biochemical test results for erythrocyte PPIX and Zn-protoporphyrin IX (Zn-PPIX) from the Danish population was reviewed together with FECH and ALAS2 mutation status when available. Erythrocyte PPIX and Zn-PPIX had been analyzed using solvent extraction followed by isocratic HPLC with flourimetric detection. The reference interval for PPIX and Zn-PPIX was 0.0-0.5 and 0.0-1.5 µmol/L, respectively. FECH and ALAS2 were mutation analyzed using conventional techniques.
Fifty-six patients were diagnosed with EPP based on increased PPIX (PPIX > 4 µmol/L). At the end of 2010 53 patients (26 men and 27 women aged 7.0-80.1 and 9.4-73.5 years, respectively) were still alive (2 women aged 86 and 90 years, and one man aged 86 years died during the period 2000-2010). One man (aged 39 years) had liver transplantation performed during the period. The total number of samples was 608, ranging from 1-33 (mean 10.9) in individual patients. The PPIX and Zn-PPIX concentrations varied between 4.7-408.6, and 0.8-21.5 µmol/L, respectively, and 4.7-110.0 (mean 41.6) and 0.8-7.2 (mean 2.8) µmol/L, respectively, when excluding 33 samples from the liver transplanted patient. All 608 samples except 10 had increased Zn-PPIX concentration in relation to the reference interval. DNA analysis was performed in samples from 26 patients. Six different FECH mutations were identified in 15 patients in combination with the low activity allele IVS3-48T>C. The same polymorphism (IVS1-23C>T) was identified in three mutation negative patients in combination with the low activity allele IVS3-48T>C. In eight patients only the low activity allele IVS3-48T>C was found. The prevalence of EPP at the end of year 2010 was 1: 103,774 in the Danish population (5.5 mill. inhabitants). The prevalence of EPP was very different between the five Danish regions, ranging from 1: 623,866 in Central Denmark Region to 1: 57,320 in the Capital Region of Denmark.
In conclusion the prevalence of EPP in Denmark is relatively high compared to other countries; United Kingdom 1: 140,000, Sweden 1: 180,000, South Africa European immigrant population 1: 152,000, and the Netherlands 1: 75,000.
OriginalsprogEngelsk
Publikationsdato5. apr. 2011
Antal sider1
StatusUdgivet - 5. apr. 2011
BegivenhedPorphyrins and Porphyrias Conference - Cardiff, Storbritannien
Varighed: 10. apr. 201114. apr. 2011

Konference

KonferencePorphyrins and Porphyrias Conference
LandStorbritannien
ByCardiff
Periode10/04/201114/04/2011

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