title: Autosomal genome-wide linkage analysis to identify loci for gallbladder wall thickness in Mexican Americans.
abstract: The significance of gallbladder wall thickness (GBWT) in regard to gallbladder disease (GBD) is not completely understood. Thickening of the gallbladder wall has been observed in patients with acute calculous and acalculous cholecystitis and chronic cholecystitis. However, various pathologic processes, such as gallbladder cancer and nonbiliary disorders such as liver cirrhosis and viral hepatitis, could also cause thickening of the gallbladder wall. To date, there is no report available on the genetic factors influencing GBWT. Therefore we sought to estimate the heritability (h2) of GBWT and to perform a genome-wide search to identify the susceptibility genes for GBWT, using data from the San Antonio Family Diabetes/Gallbladder Study (SAFDGS), a family study of Mexican Americans. GBWT was measured by ultrasound. After adjusting for the significant effects of age, sex, GBD (i.e., asymptomatic gallstones), metabolic syndrome, and duration of type 2 diabetes (T2DM), GBWT was found to be under significant and appreciable additive genetic influences (h2 +/- SE = 0.38 +/- 0.09, P < 0.0001). The strongest evidence for linkage occurred between markers D11S912 and D11S968 on chromosome 11q24-q25 (LOD = 2.7), where we have already shown suggestive evidence for linkage of GBD (LOD = 2.7) in a subset of our SAFDGS data. Potential evidence for linkage occurred at markers D1S1728 (1p31.1; LOD = 1.4) and D16S748 (16p13.1; LOD = 1.4), respectively. In conclusion, our study provides suggestive evidence for linkage of GBWT on chromosome 11q in Mexican Americans, and future tasks of mapping susceptibility gene(s) for GBD and its related traits, such as GBWT, in this chromosomal region can be fruitful.
authors.affiliation: Department of Genetics, Southwest Foundation for Biomedical Research, P.O. Box 760549, San Antonio, TX 78245-0549, USA.
authors.forename: Narahari
authors.initials: N
authors.lastname: Samudrala
authors.forename: Vidya S
authors.initials: VS
authors.lastname: Farook
authors.forename: Gerald D
authors.initials: GD
authors.lastname: Dodd
authors.forename: Sobha
authors.initials: S
authors.lastname: Puppala
authors.forename: Jennifer
authors.initials: J
authors.lastname: Schneider
authors.forename: Sharon
authors.initials: S
authors.lastname: Fowler
authors.forename: Richard
authors.initials: R
authors.lastname: Granato
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Dyer
authors.forename: Rector
authors.initials: R
authors.lastname: Arya
authors.forename: Laura
authors.initials: L
authors.lastname: Almasy
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Jenkinson
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Diehl
authors.forename: John
authors.initials: J
authors.lastname: Blangero
authors.forename: Ravindranath
authors.initials: R
authors.lastname: Duggirala
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics; D005260:Female; D005705:Gallbladder Diseases / Q000000981:diagnostic imaging / Q000208:ethnology / Q000235:genetics*; D008040:Genetic Linkage / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D015894:Genome, Human; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000235:genetics; D017058:Mexican Americans / Q000235:genetics*; D008875:Middle Aged; D013781:Texas; D014463:Ultrasonography