Expanding the spectrum of progressive familial intrahepatic cholestasis: A report of 3 cases.

Objectives: Progressive familial intrahepatic cholestasis (PFIC) is a group of autosomal recessive disorders caused by defects in bile secretion or transport usually presenting as cholestasis in pediatric age. Herewith, we describe 3 PFIC cases with diagnostic challenges and highlight the role of genetic analysis.

Methods: The clinical history, laboratory data, liver biopsy, and molecular analysis for each case were reviewed.

Results: Case 1, a Hispanic male from Puerto Rico with hepatomegaly since age 2 months, was eventually diagnosed with PFIC3 following identification of a homozygous splice site variant in ATP binding cassette subfamily B member 4 (ABCB4) (c.2784-12T>C) at age 17 years by whole-exome sequencing (WES). Case 2 was a 37-year-old man with a history of alcoholism, abnormal liver function tests, and ductopenia on biopsy. Molecular testing revealed a pathogenic heterozygous ABCB4 mutation (c.1633C>T) variant leading to a diagnosis of PFIC3. Case 3 was a 2-year-old female initially presenting as a drug-induced liver injury but was diagnosed with PFIC10 following identification of a heterozygous frameshift mutation (p.Asp300Trpfs*19) and a heterozygous missense mutation (c.1357T>C) in myosin VB (MYO5B) by WES.

Conclusions: These PFIC cases highlight the heterogenous presentation and diagnostic challenges, and they emphasize the role of next-generation sequencing, particularly the utility of WES.