Product information and disease description Place of product in therapy Disease description Epidemiology

Prevalence of Erythropoietic protoporphyria or X-linked protoporphyria

9 evidence topics · 10 sources

Reported prevalence range and sex distribution

“EPP is equally common in women and men. The prevalence ranges from 1:75,000 in the Netherlands (as the result of a founder effect) to 1:200,000 reported in Wales” (opens the source at this quote in a new tab)
“The prevalence of EPP may vary based on the population allele frequency of the low-expression c.315-48T>C allele, which ranges from approximately 1%-3% in Africans to approximately 43% in Japanese.” (opens the source at this quote in a new tab)

Prevalence of the protoporphyria group and the X-linked share

“The protoporphyrias are a group of three ultra‐rare genetic disorders of the erythroid heme biosynthesis (prevalence between 1:75000 and 1:100000), all leading to the accumulation of protoporphyrin IX (PPIX) in erythrocytes.” (opens the source at this quote in a new tab)
“About 4%–10% of protoporphyria patients suffer from XLEPP, which shows an X‐linked dominant inheritance.” (opens the source at this quote in a new tab)

United States patient count and X-linked share of cases

“It is estimated that the disorder occurs in about 1 in about 75,000 to 1 in 200,000 individuals in Europe. The number of patients affected by these disorders in the US is unknown. XLP accounts for about 10% of cases in the United States.” (opens the source at this quote in a new tab)

Genetic prevalence in the UK Biobank exceeds diagnosed prevalence

“Based on the incidence of EPP in Europe, the prevalence of EPP was estimated to be 0.00092%.” (opens the source at this quote in a new tab)
“Analysis of pathogenic FECH variants in the UK Biobank provides evidence that EPP prevalence is 0.0059% (95% CI: 0.0042%−0.0076%), 1.7–3.0 times more common than previously thought in the UK.” (opens the source at this quote in a new tab)

Diagnosed compared with exome-based prevalence

“The disease prevalence of EPP was estimated to be 1:109,000 in Europe, but more recent data using exome databases show a prevalence approximating 1:17,000 in Caucasians.” (opens the source at this quote in a new tab)

Heterogeneity of prevalence between European countries

“The prevalence of erythropoietic protoporphyria (EPP) was less uniform between countries and, in some countries, exceeded previous estimates.” (opens the source at this quote in a new tab)
“the prevalence of EPP may be increasing due to improved diagnosis and its greater recognition as a cause of photosensitivity” (opens the source at this quote in a new tab)

X-linked protoporphyria as a proportion of the protoporphyria phenotype in the United Kingdom and the United States

“Based on studies from the UK, XLP appears to account for about 2% of individuals with the erythropoietic protoporphyria phenotype” (opens the source at this quote in a new tab)
“In the US, XLP accounts for about 10% of individuals with the erythropoietic protoporphyria phenotype” (opens the source at this quote in a new tab)

Observed diagnosis distribution in the United States natural history study

“A total of 322 patients, 294 (91.3%) with EPP (132 men, 152 women) and 28 (8.7%) with XLP (12 men, 15 women, 1 unknown), were enrolled in the LS at the time of analysis.” (opens the source at this quote in a new tab)

Genotype distribution in the Italian national cohort

“most (164; 91.3%) were FECH mutations on one allele in association with the hypomorphic variant, c.315-48C, on the other (classic EPP), and nine (5.2%) were ALAS2 mutations (X-linked EPP)” (opens the source at this quote in a new tab)