P1381 - A New Genetic Variant for Intrahepatic Cholestasis of Pregnancy

Vanessa F. Eller, MD¹, Kelly Dale, FNP, MSN², Naim Alkhouri, MD^2
1University of Arizona College of Medicine, Phoenix, AZ; ²Arizona Liver Health, Peoria, AZ

Introduction: Intrahepatic cholestasis of pregnancy (ICP) can present late in pregnancy with pruritus, elevated liver enzymes, and elevated serum bile acids. Some women continue to experience cholestasis often with pruritus that occurs outside of pregnancy. Genetic predisposition is often implicated in ICP specifically with mutations in the adenosine triphosphate (ATP)ase phospholipid transporting 8B1 (ATP8B1), ATP-binding cassette subfamily B member 11 (ABCB11), and ATP-binding cassette subfamily B member 4 (ABCB4) genes that are associated with progressive familial intrahepatic cholestasis (PFIC) types 1, 2, and 3, respectively. In this case report, we discuss an unusual case of a patient who presented with ICP and pruritus and was found to be a carrier for a PFIC10 mutation in the myosin VB (MYO5b) gene.

Case Description/Methods: The patient is a 34-year-old female who presented with mildly elevated liver enzymes and occasional pruritis. Per medical review, the patient only had one previous episode of elevated liver enzymes when she was diagnosed with ICP seven years prior, which spontaneously resolved after delivery. Lab work revealed aspartate transaminase 23 U/L, alanine transaminase 33 U/L, and alkaline phosphatase 65 IU/L. The patient underwent genetic testing and was found to be a carrier of PFIC10 with heterozygous genetic mutations in MYO5B. Further genetic counseling was recommended.

Discussion: MYO5B mutations are associated with microvillus inclusion disease (MVID) which presents as intractable diarrhea. A recent study identified multiple phenotypes of MYO5B, one of which had predominant cholestatic symptoms and little to no bowel involvement, likely the case in this patient. Additionally, intrahepatic cholestasis of pregnancy (ICP), which was this patient’s first presentation of PFIC, is commonly associated with a heterozygous mutation in the ABCB4 transporter as seen in PFIC3. However, a heterozygous mutation of MYO5B has not yet been associated with this presentation. To our knowledge, this is the first case of ICP to be associated with heterozygosity for PFIC10 mutation.


Disclosures:


Vanessa F. Eller, MD¹, Kelly Dale, FNP, MSN², Naim Alkhouri, MD². P1381 - A New Genetic Variant for Intrahepatic Cholestasis of Pregnancy, ACG 2024 Annual Scientific Meeting Abstracts. Philadelphia, PA: American College of Gastroenterology.