Related Experiment Video
Updated: May 14, 2026

In Vivo Functional Study of Disease-associated Rare Human Variants Using Drosophila
Published on: August 20, 2019
The molecular basis of the LU:7 and LU:-7 phenotypes
1Laboratory of Immunochemistry, New York Blood Center, 310 East 67th Street, New York, NY 10065, USA.
Abstract:
The Lutheran blood group system currently consists of 20 antigens that have been assigned ISBT numbers. Of these, all but LU7 have been associated with one or more nucleotide changes in LU. The purpose of this study was to determine the molecular basis associated with the LU:-7 phenotype. We obtained a stored sample from one proband with this phenotype and sequenced LU. Using genomic DNA, exons 1 through 15, and their flanking intronic regions, of LU were amplified by polymerase-chain reaction, and the products were sequenced. A homozygous novel missense nucleotide change of 1274A>C in exon 10 of LU was observed. This change is predicted to encode Ala at position 425 in place of Glu of the consensus Lu glycoprotein. Based on these results, and an absence of a record of this change in the Single Nucleotide Polymorphism database, Glu425 in the Lu glycoprotein is required for expression of Lu7, and Ala425 is associated with the LU:-7 phenotype. This completes the molecular basis associated with all antigens known to be in the Lutheran blood group system.
Related Concept Videos
Epistasis
Pleiotropy
Lethal Alleles
Lucien Cuénot discovered lethal alleles in 1905 while studying the inheritance of coat color in mice. The agouti gene is responsible for the color of the coat in mice. This gene codes for an agouti-signaling protein, which is responsible for melanin distribution in mammals. The wild-type allele gives rise to gray-brown coat color in mice, while the mutant allele gives rise to yellow coat color. In addition to coat color, the agouti gene is associated with the yellow...
Genetic Lingo
Incomplete Dominance
Epistasis Analysis

