Progressive familial intrahepatic cholestasis type 3: Report of four clinical cases, novel ABCB4 variants and long-term follow-up

Abstract

Introduction and objectives: Progressive familial intrahepatic cholestasis type 3 (PFIC-3) is a rare autosomal recessive cholestatic liver disorder caused by mutations in the ABCB4 gene. The aim of this study was to present the phenotypic and genotypic spectrum of 4 Polish PFIC-3 patients diagnosed in a one-referral centre.

Materials and methods: The study included 4 patients with cholestasis and pathogenic variants in the ABCB4 gene identified by next-generation sequencing (NGS) of a targeted-gene panel or whole exome sequencing (WES). Clinical, laboratory, histological, and molecular data were collected.

Results: Four patients (three males) were identified. The age at first noted clinical signs and symptoms was 6, 2.5, 14, and 2 years respectively; the mean age was 6 years. Those signs and symptoms include pruritus (2 out of 4 patients) and hepatomegaly with splenomegaly (4 out of 4 patients). The age at the time of referral to our centre was 9, 3, 15, and 2.5 years respectively, while the mean age was 7 years. Chronic cholestatic liver disease of unknown aetiology was established in all of them. The NGS analysis was performed in all patients at the last follow-up visit. Three novel variants including c.902T>A, p.Met301Lys, c.3279+1G>A, p.?, and c.3524T>A, p.Leu1175His were identified. The time from the first consultation to the final diagnosis was 14, 9, 3, and 1 year respectively; the mean was 6.8 years. A detailed follow-up was presented.

Conclusions: The clinical phenotype of PFIC-3 could be variable. The clinical and biochemical diagnosis of PFIC-3 is difficult, thus the NGS study is very useful in making a proper diagnosis.

Keywords: Children; Cholestasis; Liver transplantation; Next-generation sequencing; Progressive familial intrahepatic cholestasis.