EPP diagnosis took 3 years and a second liver biopsy for boy in Japan
Teenager's case study highlights importance of timely diagnosis and treatment
For a teenage boy in Japan, it wasn’t until getting a second liver biopsy — nearly three years after his initial one — that he was accurately diagnosed with erythropoietic protoporphyria (EPP).
This case highlights that “EPP should be considered in young patients with unexplained liver dysfunction, skin symptoms, and seasonal changes in symptoms,” researchers wrote.
The boy’s situation was described in a study, “Definitive Confirmation of Erythropoietic Protoporphyria via Re-biopsy Three Years After Initial Liver Biopsy at Age 15,” published in the journal Cureus.
EPP caused by mutations in FECH gene
EPP is a form of porphyria caused by mutations in the FECH gene. As a result of these mutations, a molecule called protoporphyrin builds up to toxic levels in body tissues, particularly in the skin, blood, and liver, causing damage.
“Because of its often subtle and unspecific clinical symptoms, the disorder can be overlooked for years, resulting in a major delay between disease onset and diagnosis, and in a high degree of suffering in affected individuals,” the researchers wrote.
A team of scientists in Japan described the case of a teenager who was diagnosed with EPP following a complicated diagnostic journey.
The boy had sought care from his primary physician in 2018 due to fever and vomiting. Laboratory tests suggested liver dysfunction, which prompted a liver biopsy. The biopsy revealed the presence of unusual brown spots, as well as scarring in some parts of the liver.
At the time, he was diagnosed with severe cholestasis (reduced movement of bile through the liver) and liver inflammation of unknown origin.
To avoid a delayed diagnosis, EPP should be considered in the differential diagnosis of unexplained liver dysfunction in young patients.
Nearly two years later, in June 2020, the patient went to his primary physician with complaints of upper abdominal pain, and again, laboratory tests suggested liver dysfunction. He was then referred to a specialty center for further investigation.
At the center, discussions with the patient revealed he had been getting recurrent skin lesions on sun-exposed areas, especially during the summer, for the past several years. This is a characteristic symptom of EPP that led clinicians to suspect this form of porphyria.
“Porphyria should be considered a potential cause of liver damage in young patients, especially if photosensitivity is present,” the team wrote.
A second liver biopsy was performed in August 2021, again revealing the presence of brown spots and scarring in liver tissue. Scarring was more pronounced in the second biopsy than in the original one.
More detailed imaging of the brown spots indicated that they contained porphyrin, suggestive of porphyria. The team noted that this type of detailed imaging is not always performed on liver biopsy samples.
Liver scarring found to be elevated after second biopsy
“In this case, EPP was overlooked at the first biopsy, and almost three years passed without appropriate treatment. As a result, the liver fibrosis degree was elevated,” the scientists wrote.
Further laboratory analyses revealed elevated protoporphyrin levels in the patient’s blood, and genetic testing confirmed he carried a mutation in the FECH gene. The same mutation was also found in his mother and older brother, who upon questioning also reported experiencing skin damage due to sunlight (photosensitivity), a common porphyria symptom.
“To avoid a delayed diagnosis, EPP should be considered in the differential diagnosis of unexplained liver dysfunction in young patients,” the researchers wrote, highlighting the importance of detailed imaging of liver biopsy samples as part of the diagnostic evaluation.
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