A quantitative trait locus (QTL) on chromosome 6q influences birth weight in two independent family studies.
Low birth weight is an important cause of infant mortality and morbidity worldwide. Birth weight has been shown to be inversely correlated with adult complex diseases such as obesity, type-2 diabetes and cardiovascular disease. However, little is known about the genetic factors influencing variation in birth weight and its association with diseases that occur in later life. We, therefore, have performed a genome-wide search to identify genes that influence birth weight in Mexican-Americans using the data from the San Antonio Family Birth Weight Study participants (n=840). Heritability of birth weight was estimated as 72.0+/-8.4% (P<0.0001) after adjusting for the effects of sex and term. Multipoint linkage analysis yielded the strongest evidence for linkage of birth weight (LOD=3.7) between the markers D6S1053 and D6S1031 on chromosome 6q. This finding has been replicated (LOD=2.3) in an independent European-American population. Together, these findings provide substantial evidence (LOD(adj)=4.3) for a major locus influencing variation in birth weight. This region harbors positional candidate genes such as chorionic gonadotropin, alpha chain; collagen, type XIX, alpha-1; and protein-tyrosine phosphatase, type 4A, 1 that may play a role in fetal growth and development. In addition, potential evidence for linkage (LOD>or=1.2) was found on chromosomes 1q, 2q, 3q, 4q, 9p, 19p and 19q with LODs ranging from 1.3 to 2.7. Thus, we have found strong evidence for a major gene on chromosome 6q that influences variation in birth weight in both Mexican- and European-Americans.
Arya
Rector
R
Division of Clinical Epidemiology, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, 78229-3900, USA. arya@uthscsa.edu
Demerath
Ellen
E
Jenkinson
Christopher P
CP
Göring
Harald H H
HH
Puppala
Sobha
S
Farook
Vidya
V
Fowler
Sharon
S
Schneider
Jennifer
J
Granato
Richard
R
Resendez
Roy G
RG
Dyer
Thomas D
TD
Cole
Shelley A
SA
Almasy
Laura
L
Comuzzie
Anthony G
AG
Siervogel
Roger M
RM
Bradshaw
Benjamin
B
DeFronzo
Ralph A
RA
MacCluer
Jean
J
Stern
Michael P
MP
Towne
Bradford
B
Blangero
John
J
Duggirala
Ravindranath
R
D001724:Birth Weight / Q000235:genetics*; D002877:Chromosomes, Human / Q000235:genetics; D002896:Chromosomes, Human, Pair 6 / Q000235:genetics*; D005260:Female; D008040:Genetic Linkage; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D017058:Mexican Americans; D040641:Quantitative Trait Loci