Microsatellites and intragenic polymorphisms of transforming growth factor beta and platelet-derived growth factor and their receptor genes in Native Americans with systemic sclerosis (scleroderma): a preliminary analysis showing no genetic association.
OBJECTIVE
Abnormalities of transforming growth factor beta (TGFbeta) and platelet-derived growth factor (PDGF) alpha and beta and/or their receptors have been demonstrated in systemic sclerosis (SSc). This study aimed to determine whether genetic polymorphisms in or near the TGFbeta and PDGF gene families were associated with susceptibility to SSc in a Native American population with a high disease prevalence.


METHODS
Genotyping of 5 intragenic polymorphisms within the TGFbeta1 gene and mapping of 35 microsatellites near the genes for TGFbeta1, latent TGFbeta1 binding protein (LTBP1), TGFbeta receptors I and II, PDGFalpha, PDGFbeta, PDGF receptor alpha, and PDGF receptor beta was performed in 19 SSc patients, 76 controls, and 42 family members. Allele distributions and frequencies were examined between SSc patients and controls, and marker haplotypes were examined in families when allele frequencies appeared to be different between patients and controls.


RESULTS
Although 1 polymorphism within the TGFbeta1 gene (TGFbeta1) was modestly increased in the SSc patients, this did not maintain statistical significance after correction. Similarly, 1 microsatellite (D9S120) near the TGFbeta receptor I gene (TGFBR1) showed a significant disturbance of allele frequencies between patients and controls; however, it did not form a disease-associated haplotype with other nearby markers. Weak disturbances of markers near PDGFalpha (PDGFA) and PDGFbeta, (PDGFB) also failed to maintain significance after correction. Both PDGF receptor genes (PDGFRA and PDGFRB) also showed no disease associations.


CONCLUSIONS
The results of these preliminary analyses suggest that genetic anomalies of the TGFbeta1 and PDGF gene families are not likely to explain the dysregulation seen in SSc or to account for the susceptibility to SSc in this population.
Zhou
X
X
University of Texas-Houston Medical School, 77030, USA.
Tan
F K
FK
Stivers
D N
DN
Arnett
F C
FC
D000483:Alleles; D020022:Genetic Predisposition to Disease; D006720:Homozygote; D006801:Humans; D007198:Indians, North American / Q000235:genetics*; D018895:Microsatellite Repeats / Q000235:genetics*; D010982:Platelet-Derived Growth Factor / Q000235:genetics*; D011110:Polymorphism, Genetic; D017479:Receptors, Platelet-Derived Growth Factor / Q000235:genetics*; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics*; D012595:Scleroderma, Systemic / Q000208:ethnology* / Q000235:genetics*; D016212:Transforming Growth Factor beta / Q000235:genetics*
D010982:Platelet-Derived Growth Factor; D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta; D017479:Receptors, Platelet-Derived Growth Factor