The young age of the patient, recurrence of gallstones after cholecystectomy and intrahepatic gallstones suggested a subtype of the low-phospholipid associated cholelithiasis syndrome, a monogenic form of cholesterol cholelithiasis due to variations of the ABCB4 gene that encodes the canalicular phospholipid transporter MDR3.
A smaller group of patients might develop gallstones primarily due low phosphatidylcholine concentrations in bile as a result of loss-of-function mutations of the ABCB4 transporter (low phospholipid-associated cholelithiasis syndrome).
48 mutations of MDR3 gene have been reported in humans to date, from which 43 (89.5%) in the coding region, and 5 splice site mutations have been associated to cholesterol cholelithiasis.
ABCB4 gene mutations leading to a multidrug resistance (MDR)3-P-glycoprotein deficiency are related to, among other diseases, recurrent cholelithiasis.
Low phospholipid-associated cholelithiasis (LPAC) is characterized by the association of ABCB4 mutations and low biliary phospholipid concentration with symptomatic and recurring cholelithiasis.
Low phospholipid-associated cholelithiasis (LPAC) is characterized by the association of ABCB4 mutations and low biliary phospholipid concentration with symptomatic and recurring cholelithiasis.
A second ABC transporter, the hepatic phosphatidylcholine translocase ABCB4, increases the risk for gallstone disease, gallbladder cancer and chronic liver diseases in general, whereas the common PNPLA3 risk variant p.I148M decreases gallstone risk.
In our study we investigated the contribution of heterozygosity for common variations considered either potentially pathogenic or susceptibility alleles for cholesterol cholelithiasis in adults (c.523A>G (p.Thr175Ala) and c.1954A>G (p.Arg652Gly) in ABCB4, c.1331T>C (p.Val444Ala) in ABCB11 and c.55 G>C (p.Asp19His) in ABCG8) to the aetiology of paediatric idiopathic gallstone disease.
This study demonstrates that splicing mutations in the MDR3 gene can cause ICP with normal gamma-GT and may be associated with stillbirths and gallstone disease.
Whereas rare mutations of this transporter were known to cause progressive familial intrahepatic cholestasis, the genome-wide association studies in Iceland find the common ABCB4 variant c.711A>T to be a general risk factor for elevated aminotransferases and higher impact variants to be potential determinants of early-onset gallstone disease, cholestasis of pregnancy, liver cirrhosis, and hepatobiliary cancer.
Low phospholipid-associated cholelithiasis (LPAC) is characterized by the association of ABCB4 mutations and low biliary phospholipid concentration with symptomatic and recurring cholelithiasis.
Our results show that ABCB4 gene mutations represent a major genetic risk factor in a symptomatic and recurring form of cholelithiasis in young adults.
Various polymorphisms (A632V, T400K, D19H, M429V, and C54Y) in the ABCG8 and ABCG5 (Q604E) gene have been found to be associated with several facets of cholesterol metabolism, including baseline cholesterol level, cholesterol kinetics, individual responsiveness of plasma cholesterol to dietary and pharmaceutical interventions for hypercholesterolemia, and increased risk of gallstones.
Patients with Gaucher disease type 1 (GD1) show an altered lipid profile and a certain degree of insulin resistance, which might contribute to cholelithiasis (CL) and could possibly be associated with ABCG5/ABCG8 gene variants.
Consistent with the mouse model, heterozygosity for the lithogenic ABCG8 allele was associated with gallstones in humans; 21.4% of gallstone patients carried the heterozygous D19H genotype, compared with 8.6% of controls (OR = 2.954; P = 0.026).
To test the hypothesis that ABCG8 (adenosine triphosphate-binding cassette transporter G8) Asp19His (D19H) genotype predicted risk of gallstones and biliary cancer in the general population, we studied 62,279 white individuals from The Copenhagen City Heart Study and The Copenhagen General Population Study, randomly selected to reflect the adult Danish population aged 20 to 80+ years.