A novelABOallele caused by an in-frame triplet deletion inABOgene

Identification of a novel FUT1 allele with two mutations in a Chinese para-Bombay individual

BACKGROUND

The para-Bombay phenotype often results from a silenced β-D-galactoside 2-α-fucosyltransferase 1 (FUT1) gene (h/h) but an active FUT2 (Se/Se or Se/se) gene. We identified a para-Bombay phenotype with two novel mutations in the FUT1 gene and homozygous mutated FUT2 (se357, 385 /se357, 385 ) genes.

STUDY DESIGN AND METHODS

Red blood cell phenotype was detected by using a standard serologic technique. The entire coding regions of the FUT1 and FUT2 genes were amplified and direct sequenced using genomic DNA.

RESULTS

No ABH substance was detected on the surface of the proband's red blood cells. Anti-A, anti-B, and anti-H were identified in serum. Genetic studies indicated that the proband's ABO genotyping was A102/O01 and that the FUT2 phenotype was se357, 385 /se357,385 . The sample was homozygous for two FUT1 mutations: c.958insG and c.961G > A.

CONCLUSION

Two novel FUT1 mutations have been identified in the proband's FUT1 gene. The insertion mutation in the FUT1 that caused a shift of the open reading frame and formed a termination codon early at Amino Acid Position 334 may be the main reason for H deficiency in this case.

Sequence analysis of the human fucosyltransferase 1 and 2 genes in Tibetan blood donors: identification of three novel alleles

BACKGROUND

The α(1,2)-fucosyltransferase gene 1 (FUT1) and 2 (FUT2), respectively, regulate H antigen synthesis in red blood cells and body fluids. Genetic polymorphisms of FUT1 and FUT2 are ethnically and geographically specific.

STUDY DESIGN AND METHODS

Healthy unrelated Tibetan blood donors (n = 200) from the Tibet Autonomous Region of China were recruited for this study. The entire FUT1 and FUT2 coding regions were amplified and sequenced. The haplotypes including novel single-nucleotide polymorphisms (SNPs) were determined by clone sequencing.

RESULTS

In Tibetans, the major FUT1 allele was wild-type allele with a frequency of 97.75%. One novel FUT1 allele was defined by a novel synonymous mutation (846T>G). The two most common FUT2 alleles were functional allele Se(357) with a frequency of 32.75% and nonfunctional allele se(357,385) with a frequency of 55%. Two new FUT2 alleles were found at low frequency. They were characterized by two novel SNPs on the basis of se(357,385) : 617 T>G (V206G) and 841 G>A (G281R).

CONCLUSION

Three new alleles in FUT1 and FUT2 genes were identified in the study. The allelic polymorphisms of FUT1 and FUT2 in Tibetans show a population-specific manner.