SEGREGATION AND LINKAGE ANALYSES OF 12 BLOOD AND SERUM GROUP SYSTEMS

Twelve Mood and serum group systems have been studied ¡11 100 Swedish families including a total of 238 children with special regard to segregation and genetic linkage. The results of the segregation analyses agreed with expectation except in the Hp system. Here, Up 2-2 X Hp 2-1 matings showed an excess of Hp 2-1 children as has also been observed in previous Scandinavian studies. This excess is significant in the combined Scandinavian series. Other populations seem to show a different pattern as an excess of Hp 2-2 children is seen in the larger studies from other regions, notably Germany and Brazil. These deviations are not likely to have any simple explanation; they are not directly related to the Up gene frequencies, and a search for other single factors of importance has been unsuccessful so far. The linkage analyses gave further support to the assumption that the loci of the blood and serurn groups studied here arc unlinked or, in a few cases where information is still insufficient, at least not closely linked. A strong suggestion of linkage between the Ag and Gc loci appeared in the present material as no crossover was observed, a finding which is markedly different from the result of a Swias-Italian linkage analysis of the same relation. Further Scandinavian studies are being performed with the aim of elucidating this apparent discrepancy. © 1969 S. Karger AG, Basel.