Endocrine Abstracts

Background

Acute intermittent porphyria (AIP), a rare autosomal-dominant inherited disorder, caused by pathogenic mutations in the gene encoding porphobilinogen deaminase (PBGD). To explore its clinical characteristics, we investigated three patients with AIP admitted to our hospital.

Methods

In this study, patients successfully diagnosed with AIP and treated at the First Hospital of Shanxi Medical University since January 1, 2016, were enrolled. Information regarding the medical history, symptoms, treatments, prognoses, and gene mutations of these patients was collected and analysed.

Results

Three patients, all young women, were included in the study. Their main symptoms were abdominal pain, accompanied by abdominal distension, nausea, vomiting, hypertension, tachycardia, etc. Laboratory results from all three subjects showed severe hyponatremia and hyperuricemia. At the same time, patients A and B suffered from epileptic seizures when their serum sodium levels sharply decreased. After carbohydrate loading therapy, the symptoms of all three patients were alleviated. And the earlier carbohydrate loading was administered, the faster the symptoms were relieved and the better the prognosis would be. However, high-doses of glucose intravenously administered may exacerbate hyponatremia. During the treatment, their uric acid levels firstly dropped and then rose again as their conditions improved. There were different mutations in the PBGD gene that had been detected in the three patients: Patient A with the heterozygous deletion frameshift mutation (c.730_731del), Patient B with c.1078_1132del, Patient C with the intronic mutation c.160 + 5G > C.

Conclusion

The clinical manifestations of AIP are complex and variable. In patients with unexplained abdominal pain, hyponatraemia, and neuropsychiatric symptoms, acute episodes of AIP should be considered. Our study indicated that seizures in patients with AIP might be associated with hyponatremia. Gene sequencing can identify possible pathogenic mutations and improve the accuracy of diagnosis. Carbohydrate loading is the main treatment to alleviate the symptoms of AIP. Meanwhile, patients’ serum sodium levels should be monitored and corrected in time during glucose therapy.