The Phenotype Lu(a−b−) Together with Unconventional Kidd Groups in One Family

Abstract

Minus‐minus blood group phenotypes are characterized by the absence of any detectable phenotypic representation of the alleles expected at the determining gene loci. Double minus phenotypes have been found in most blood group systems but all individuals thus far tested for the Lutheran factors have been Lu(a+b+), Lu(a+b+) or Lu(a−+). Six individuals with the hitherto undisclosed blood group Lu(a−b−) were found in three generations of a Caucasian family.Unlike the other minus‐minus phenotypes, to which recessive genetical backgrounds have been assigned, Lu(a−b−) appears to be a dominant character.The Kidd groups of the family are also anomalous: The proposita and her two brothers are Lu(a−b−), Jk(a+b−) yet their father is Lu(a−b−), Jk(a−b+) and their mother is Lu(a−b+), Jk(a+b−). Possible genetical backgrounds are discussed.

A Case of Suppressed Lu^a and Lu^b Antigens

“…Her surviving brother has not yet been contacted: whatever his Lutheran groups may be they cannot show whether Mrs. Di. belongs to the dominant [1] or the recessive [2] type of Lu(a-b-). If he were his sister, it wo old confirm the assumption that the inhibition is, as in other families, genetic in origin.…”

Human erythrocyte antigens. Regulation of expression of a novel erythrocyte surface antigen by the inhibitor Lutheran In(Lu) gene.

“…Lutheran antigens were the first erythrocyte blood group system shown to be controlled by an independent dominant inhibitor gene (1). This Lutheran inhibitory In(Lu)l gene is an autosomal gene, not linked to the Lutheran loci, which in the heterozygote, suppresses almost totally the expression of Lutheran antigens (2)(3)(4)(5)(6)(7).…”

The Frequency of the Lutheran Blood Group Antigens, as Defined by Anti-Lu^a, in the Oslo Population

“…The phenotype frequencies were thus: Lu(a+): 8.133%, Lu(a-): 91.867%. As the phenotype Lu(a-b-) is extremely rare [9,10] In the Lua antigen as one goes northwards, the highest frequencies being ob served in the Danes and the Norwegians. The Lua antigen occurs significantly more frequently in the Norwegians than in the Swiss (12 = 9.27 for 1 d.f., P = 0.002) or the Italians (%2 = 7.33 for 1 d.f., P = 0.007).…”