ABCB4 gene mutation-associated cirrhosis with systemic amyloidosis: A case report.

BACKGROUND: Gene mutations in ATP-binding cassette, subfamily B ( ABCB4 ) lead to autosomal recessive disorders. Primary light amyloidosis is a rare and incurable disease. Here, we report a rare case of liver cirrhosis caused by ABCB4 gene mutation combined with primary light amyloidosis.

CASE SUMMARY: We report a case of a 25-year-old female who was hospitalized due to recurrent abdominal pain caused by calculous cholecystitis and underwent cholecystectomy. Pathological examination of the liver tissue suggested liver cirrhosis with bile duct injury. Exon analyses of the whole genome from the patient's peripheral blood revealed the presence of a heterozygous mutation in the ABCB4 gene. Bone marrow biopsy tissues, renal puncture examination, and liver mass spectrometry confirmed the diagnosis of a rare progressive familial intrahepatic cholestasis type 3 with systemic light chain type κ amyloidosis, which resulted in cirrhosis. Ursodeoxycholic acid and the cluster of differentiation 38 monoclonal antibody daretozumab were administered for treatment. Following treatment, the patient demonstrated significant improvement. Urinary protein became negative, peripheral blood-free light chain and urine-free light chain levels returned to normal, and the electrocardiogram showed no abnormalities. Additionally, the patient's lower limb numbness resolved, and her condition remained stable.

CONCLUSION: This report presents the diagnosis and treatment of liver cirrhosis, a rare disease that is easily misdiagnosed or missed.