Gene
SFTPA2 is located in the long arm of chromosome 10, close to SFTPA1. The SFTPA2 gene is 4556 base pairs in length, and 94% similar to SFTPA1. The structure of SFTPA2 consists of four coding exons (I-IV), and several 5'UTR untranslated exons (A, B, B’, C, C’,D, D’). The expression of SFTPA2 is regulated by cellular factors including proteins, small RNAs (microRNAs), glucocorticoids, etc. Its expression is also regulated by epigenetic and environmental factors.
Differences in the SFTPA2 gene sequence at the coding region determine SP-A genetic variants or haplotypes among individuals. More than 30 variants have been identified and characterized for SFTPA2 (and SFTPA1) in the population. SFTPA2 variants result from nucleotide changes in the codons of amino acids 9, 91, 140, and 223. Three of these do not modify the SP-A2 protein sequence (amino acids 9, 91, and 223), whereas the remaining one results in an amino acid substitution (amino acid 140). Six SP-A2 variants (1A, 1A0, 1A1, 1A2, 1A3, 1A5) are in higher frequency in the general population. The most frequently found variant is 1A0.
Read more about this topic: SFTPA2B