SNP Shot: Genomic Insights

Benign recurrent intrahepatic cholestasis (BRIC) is a condition marked by recurring episodes of cholestasis, a type of liver dysfunction. In these episodes, the liver's ability to secrete bile, a crucial digestive fluid, is impaired. The term "intrahepatic" indicates that the problem with bile secretion originates within the liver itself. These cholestasis episodes can persist for weeks or months, with symptom-free periods in between that can range from weeks to years.

The first episode of cholestasis typically occurs during a person's teens or twenties. It often begins with intense itching (pruritus), followed by jaundice, a yellowing of the skin and eyes, a few weeks later. Other common symptoms during these episodes include a general feeling of being unwell (malaise), irritability, nausea, vomiting, and loss of appetite. A characteristic feature of BRIC is impaired fat absorption, leading to excessive fat in the stool (steatorrhea). Due to both poor fat absorption and decreased appetite, individuals with BRIC frequently experience weight loss during cholestasis episodes.

BRIC is classified into two subtypes, BRIC1 and BRIC2, differentiated by their underlying genetic cause. However, the symptoms are identical in both types.

This condition is considered benign because it typically doesn't cause long-term liver damage. However, in some cases, these episodes of liver dysfunction can progress into a more severe and irreversible form of liver disease called progressive familial intrahepatic cholestasis (PFIC). BRIC and PFIC are sometimes viewed as different points on a spectrum of intrahepatic cholestasis disorders, reflecting varying degrees of severity.

Inheritance:

Both BRIC1 and BRIC2 are inherited in an autosomal recessive manner. This means that an individual must inherit two copies of a mutated gene, one from each parent, to develop the condition. The parents, each carrying a single copy of the mutated gene, usually don't exhibit any symptoms. In some instances, individuals with BRIC have no family history of the disorder. These cases arise from new mutations in the ATP8B1 or ABCB11 gene that occur after fertilization, and are therefore not inherited from their parents.