Genome-wide scans for microalbuminuria in Mexican Americans: the San Antonio Family Heart Study.
OBJECTIVE
Microalbuminuria, defined as urine albumin-to-creatinine ratio of 0.03 to 0.299 mg/mg, is a major risk factor for cardiovascular disease. Several genetic epidemiological studies have established that microalbuminuria clusters in families, suggesting a genetic predisposition.


METHODS
We estimated heritability of microalbuminuria and performed a genome-wide linkage analysis to identify chromosomal regions influencing urine albumin-to-creatinine ratio in 486 Mexican Americans from 26 multiplex families.


RESULTS
Significant heritability was demonstrated for urine albumin-to-creatinine ratio (h = 24%, P < 0.003) after accounting for age, sex, body mass index, triglycerides, and hypertension. Genome scan revealed significant evidence of linkage of urine albumin-to-creatinine ratio to a region on chromosome 20q12 (LOD score of 3.5, P < 0.001) near marker D20S481. This region also exhibited a LOD score of 2.8 with diabetes status as a covariate and 3.0 with hypertension status as a covariate suggesting that the effect of this locus on urine albumin-to-creatinine ratio is largely independent of diabetes and hypertension.


CONCLUSIONS
Findings indicate that there is a gene or genes located on human chromosome 20q12 that may have functional relevance to albumin excretion in Mexican Americans. Identifying and understanding the role of the genes that determine albumin excretion would lead to the development of novel therapeutic strategies targeted at high-risk individuals in whom intensive preventive measures may be most beneficial.
Arar
Nedal
N
Department of Medicine/Nephrology, University of Texas Health Science Center at San Antonio, South Texas Veterans Health Care System, 78229-4404, USA. ararn@uthscsa.edu
Nath
Subrata
S
Thameem
Farook
F
Bauer
Richard
R
Voruganti
Saroja
S
Comuzzie
Anthony
A
Cole
Shelley
S
Blangero
John
J
MacCluer
Jean
J
Abboud
Hanna
H
D000367:Age Factors; D000419:Albuminuria / Q000453:epidemiology* / Q000208:ethnology / Q000235:genetics*; D001794:Blood Pressure; D015992:Body Mass Index; D002874:Chromosome Mapping / Q000706:statistics & numerical data*; D002890:Chromosomes, Human, Pair 20 / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006801:Humans; D040582:Inheritance Patterns; D016013:Likelihood Functions; D008297:Male; D017058:Mexican Americans / Q000235:genetics*; D010375:Pedigree; D012737:Sex Factors; D013781:Texas / Q000453:epidemiology; D014280:Triglycerides / Q000097:blood
D014280:Triglycerides