Immunoglobulin M, Level Of

Grundbacher (1972) suggested that genes on the X chromosome determine the quantity of immunoglobulin M, because the concentration in serum is one-third higher in females than in males and intrafamilial correlations are higher between sons and mothers than between sons and fathers. Even higher IgM was observed in XXX females (Rhodes et al., 1969) and XO females had levels like normal males. Adinolfi et al. (1978) extended the observations in man and mouse. Washburn et al. (1965) concluded that bacterial infections are a more significant problem in males than in females. Escobar et al. (1979) measured serum concentrations of immunoglobulins G, A and M in 93 pairs of monozygotic twins, their spouses and their offspring. The hypothesis that the human X chromosome carries genes that control the level of IgM was tested with three different approaches. The results indicate that environmental factors are primarily responsible for the observed variation in the levels of IgG and IgA, whereas variance of IgM was mostly the result of X-linked gene effects. IgM deficiency as an X-linked trait leading to predisposition to meningococcal meningitis was suggested by Hobbs et al. (1967) and Hobbs (1986).