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Case Reports
. 2021 Sep;25(6):e13943.
doi: 10.1111/petr.13943. Epub 2020 Dec 14.

Successful liver transplantation in hyperornithinemia-hyperammonemia-homocitrullinuria syndrome: Case report

Pauline De Bruyne  1 , Patrick Verloo  2 , Johan L K Van Hove  3 , Bernard de Hemptinne  4 , Saskia Vande Velde  5 , Myriam Van Winckel  5 , Stephanie Van Biervliet  5 , Ruth De Bruyne  5
Affiliations
Case Reports

Successful liver transplantation in hyperornithinemia-hyperammonemia-homocitrullinuria syndrome: Case report

Pauline De Bruyne et al. Pediatr Transplant. 2021 Sep.

Abstract

Background: HHH syndrome is a rare autosomal recessive disorder of the urea cycle, caused by a deficient mitochondrial ornithine transporter. We report the first successful liver transplantation in HHH syndrome performed in a seven-year-old boy. The patient presented at 4 weeks of age with hyperammonemic coma. The plasma amino acid profile was suggestive of HHH syndrome, and the diagnosis was confirmed when sequencing of the SLC25A15 gene identified two mutations p.R275Q and p.A76D. Although immediate intervention resulted in normalization of plasma ammonia levels within 24 hours, he developed cerebral edema, coma, convulsions, and subsequent neurological sequelae. Metabolic control was difficult requiring severe protein restriction and continued treatment with sodium benzoate and L-arginine. Despite substantial developmental delay, he was referred to our center for liver transplantation because of poor metabolic control. Following cadaveric split liver transplantation, there was complete normalization of his plasma ammonia and plasma amino acid levels under a normal protein-containing diet. This excellent metabolic control was associated with a markedly improved general condition, mood and behavior, and small developmental achievements. Twelve years after liver transplantation, the patient has a stable cognitive impairment without progression of spastic diplegia.

Conclusion: This first case of liver transplantation in HHH syndrome demonstrates that this procedure is a therapeutic option for HHH patients with difficult metabolic control.

Keywords: SLC25A15; case report; inborn error of metabolism; liver failure; pediatric medicine; urea cycle defect.

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References

REFERENCES

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Supplementary concepts