What Family Members of AHP Patients Should Know: High Levels, No Symptoms
Summing UP features the latest porphyria research in easy-to-understand summaries that have been reviewed and approved by the UPA's Scientific Advisory Board of porphyria experts.
A Prospective, Blinded Study of Symptom Prevalence and Specificity of Porphyrin Precursors in Carriers of Acute Hepatic Porphyria
Published in Liver International
June 2025
Researchers studied 149 close relatives of people with acute hepatic porphyria (AHP- includes AIP, HCP and VP). The relatives had never been tested for or had symptoms of porphyria. The researchers checked the relatives’ genes, had them fill out a symptom survey, and tested their urine for two molecules – aminolevulinic acid (ALA) and porphobilinogen (PBG) - that build up in acute porphyria.
Who had the mutation?
Of the 149 relatives who participated in the study:
79 people (53%) carried an AHP gene
70 people did not carry an AHP gene
Key findings
Higher urine ALA and PBG levels – Gene carriers had much higher levels of ALA and PBG in their urine than non‑carriers. Female carriers had higher levels than male carriers.
Some symptoms appeared
27% of gene carriers reported symptoms versus 15% of non‑carriers.
The most common symptom in carriers was dark urine, and symptoms lasted longer when they occurred.
More research is needed but the higher frequency of symptoms may suggest that AHP might underlie more minor, recurring symptoms in gene carriers who have never had an acute attack.
Hidden high levels without symptoms
About 31% of carriers had very high PBG - more than 4 times the normal limit - even though they felt fine. Nearly 39% of female carriers had these high levels compared to 17% of males.
Why it matters
People who carry the gene and don’t have symptoms may still have high levels of ALA and PBG
High PBG levels could mean there is a risk of future attacks or the long-term health complications associated with acute hepatic porphyrias.
Testing family members can catch cases early, and help with monitoring and care.
What Patients and Families Should Know
If a family member has AHP, it's important to get genetic and urine testing, even if no they haven’t had an attack.
Female relatives may need extra monitoring, since they are more likely to show higher levels of ALA and PBG.
Some carriers may look healthy but still have high PBG, meaning they might need regular check‑ups.
Bottom Line
This research shows that carriers of AHP genes often have higher porphyrin levels, even if they feel fine. Testing close family members is key to finding those who might benefit from being watched more closely.
CONTENT REVIEWED BY UNITED PORPHYRIAS ASSOCIATION SCIENTIFIC ADVISORY BOARD
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