J Floros, S DiAngelo, M Koptides, AM Karinch, PK Rogan, H Nielsen, RG Spragg, K Watterberg and G Deiter
Department of Cellular and Molecular Physiology, Milton S. Hershey Medical Center, Pennsylvania State University College of Medicine, Hershey, 17033-0850, USA.

Two surfactant protein A (SP-A) genes and several alleles for each SP-A locus have been previously described. In this report we investigate the potential usefulness of the SP-A loci as markers for genetic studies. We establish conditions that allow the identification of alleles with very similar sequences; We also determine the degree of polymorphism for each SP-A locus: The heterozygosity and polymorphism information content (PIC) values for the SP-A1 locus are 0.63 and 0.55, respectively, and for the SP-A2 locus are 0.50 and 0.56. In the course of these studies, we identify one new SP-A2 allele and show that the SP- A1 and SP-A2 loci are in linkage disequilibrium (P < 0.000001). We also identify 19 of the 20 possible haplotypes in a population of n = 239. Nine of the observed haplotypes reach statistical significance (P < 0.01) in this population, and the segregation of two haplotypes (6A2/1A0 and 6A4/1A) without recombination is verified in a family pedigree. These data together indicate that both SP-A loci are sufficiently polymorphic to be good markers for use in genetic studies. Furthermore, the finding of one novel allele suggests that additional unknown SP-A alleles are yet to be found.

This article has been cited by other articles:

				H. R. S. Tagaram, G. Wang, T. M. Umstead, A. N. Mikerov, N. J. Thomas, G. R. Graff, J. C. Hess, M. J. Thomassen, M. S. Kavuru, D. S. Phelps, et al. Characterization of a human surfactant protein A1 (SP-A1) gene-specific antibody; SP-A1 content variation among individuals of varying age and pulmonary health Am J Physiol Lung Cell Mol Physiol, May 1, 2007; 292(5): L1052 - L1063. [Abstract] [Full Text] [PDF]

				A. N. Mikerov, T. M. Umstead, W. Huang, W. Liu, D. S. Phelps, and J. Floros SP-A1 and SP-A2 variants differentially enhance association of Pseudomonas aeruginosa with rat alveolar macrophages Am J Physiol Lung Cell Mol Physiol, January 1, 2005; 288(1): L150 - L158. [Abstract] [Full Text] [PDF]

				J. Madsen, I. Tornoe, O. Nielsen, C. Koch, W. Steinhilber, and U. Holmskov Expression and Localization of Lung Surfactant Protein A in Human Tissues Am. J. Respir. Cell Mol. Biol., November 1, 2003; 29(5): 591 - 597. [Abstract] [Full Text]

				X. Guo, H-M. Lin, Z. Lin, M. Montano, R. Sansores, G. Wang, S. DiAngelo, A. Pardo, M. Selman, and J. Floros Surfactant protein gene A, B, and D marker alleles in chronic obstructive pulmonary disease of a Mexican population Eur. Respir. J., September 1, 2001; 18(3): 482 - 490. [Abstract] [Full Text] [PDF]

				R. Haataja, M. Ramet, R. Marttila, and M. Hallman Surfactant proteins A and B as interactive genetic determinants of neonatal respiratory distress syndrome Hum. Mol. Genet., November 1, 2000; 9(18): 2751 - 2760. [Abstract] [Full Text] [PDF]

				G. Wang, D. S. Phelps, T. M. Umstead, and J. Floros Human SP-A protein variants derived from one or both genes stimulate TNF-alpha production in the THP-1 cell line Am J Physiol Lung Cell Mol Physiol, May 1, 2000; 278(5): L946 - L954. [Abstract] [Full Text] [PDF]

				X. Guo, H.-M. Lin, Z. Lin, M. Montano, R. Sansores, G. Wang, S. DiAngelo, A. Pardo, M. Selman, and J. Floros Polymorphisms of Surfactant Protein Gene A, B, D, and of SP-B-linked Microsatellite Markers in COPD of a Mexican Population Chest, May 1, 2000; 117(5_suppl_1): 249S - 250S. [Full Text] [PDF]

				R. L. Emanuel, J. S. Torday, Q. Mu, N. Asokananthan, K. A. Sikorski, and M. E. Sunday Bombesin-like peptides and receptors in normal fetal baboon lung: roles in lung growth and maturation Am J Physiol Lung Cell Mol Physiol, November 1, 1999; 277(5): L1003 - L1017. [Abstract] [Full Text] [PDF]

				R. R. Hoover and J. Floros SP-A 3'-UTR is involved in the glucocorticoid inhibition of human SP-A gene expression Am J Physiol Lung Cell Mol Physiol, June 1, 1999; 276(6): L917 - L924. [Abstract] [Full Text] [PDF]

				L. M. Scavo, R. Ertsey, and B. Q. Gao Human surfactant proteins A1 and A2 are differentially regulated during development and by soluble factors Am J Physiol Lung Cell Mol Physiol, October 1, 1998; 275(4): L653 - L669. [Abstract] [Full Text] [PDF]

				E. C. Crouch Collectins and Pulmonary Host Defense Am. J. Respir. Cell Mol. Biol., August 1, 1998; 19(2): 177 - 201. [Abstract] [Full Text]

				R. R. Hoover and J. Floros Organization of the Human SP-A and SP-D Loci at 10q22-q23 . Physical and Radiation Hybrid Mapping Reveal Gene Order and Orientation Am. J. Respir. Cell Mol. Biol., March 1, 1998; 18(3): 353 - 362. [Abstract] [Full Text]

				A. R. Kumar and J. M. Snyder Differential regulation of SP-A1 and SP-A2 genes by cAMP, glucocorticoids, and insulin Am J Physiol Lung Cell Mol Physiol, February 1, 1998; 274(2): L177 - L185. [Abstract] [Full Text] [PDF]