[Molecular screening for Vel- blood type and analysis of SMIM1 gene variants].

Objective: To screen for Vel- rare blood type donors and determine the frequency of SMIM1 c.64_80del allele in Yili Prefecture of Xinjiang, China.

Methods: DNA pooling and PCR-sequence-specific primers (PCR-SSP) was conducted to screen individuals carrying the SMIM1 c.64_80del variant, and Sanger sequencing of SMIM1 exon 3 was carried out to verify the genotype of those with the variation. SMIM1 intron 2 was also sequenced to identify single nucleotide polymorphisms (SNPs) that may affect the expression of Vel antigen.

Results: Among 3328 blood donors, 14 were identified as heterozygotes for the SMIM1 c.64_80del allele, its allele frequency was 0.21%; no homozygous SMIM1 c.64_80 deletions was found. For SNP rs1175550, all of the 14 individuals had an AA genotype, among whom 5 carried heterozygous 7111ins GCA variant in intron 2.

Conclusion: The allelic frequency of SMIM1 c.64_80del in Yili area is approximately 0.21%, which is reported for the first time.