variable

I'd say that heredity is a contributor to the likelihood of you getting a disease, much like stress, smoking, obesity, or bad diet.

Sounds like the deficiency is an inherited trait.

Are you sure that it's saying that the inheritance of SIgAD can be variable? There are two classes of inherited IgA deficiencies, selective (SIgAD) and variable (CVID). Here's a reference that describes both. I'd need to see the context of your statement before I could give an opinion of SIgAD being variable.

Familial inheritance of either SIgAD or CVID occurs in about 20% of cases (Fig. 1). A different population prevalence in various ethnic groups, strong familial clustering of the disorder, a predominant inheritance pattern in multiple-case families compatible with autosomal dominant transmission, and a high relative risk for siblings suggest the involvement of thus far unidentified genetic factors in the pathogenesis of IgAD/CVID [8,9]. In multiple-case families with a dominant transmission of CVID/IgAD, CVID was usually present in the parents accompanied by IgAD in descendants [9]. This is consistent with the hypothesis that CVID may develop later in life as a more severe manifestation of a common, complex genetic defect, most likely involving immunoglobulin class switching.

Ori -- is this the same Table 1 referenced in the phenotype question?

Great! It means that sometimes the inheritance is AD, or AR, or possibly even sex-linked.

Here's a description from the quote I linked above...

Quote:

Familial inheritance of either SIgAD or CVID occurs in about 20% of cases (Fig. 1). A different population prevalence in various ethnic groups, strong familial clustering of the disorder, a predominant inheritance pattern in multiple-case families compatible with autosomal dominant transmission, and a high relative risk for siblings suggest the involvement of thus far unidentified genetic factors in the pathogenesis of IgAD/CVID [8,9]. In multiple-case families with a dominant transmission of CVID/IgAD, CVID was usually present in the parents accompanied by IgAD in descendants [9]. This is consistent with the hypothesis that CVID may develop later in life as a more severe manifestation of a common, complex genetic defect, most likely involving immunoglobulin class switching.