My brother(25 yrs) has low immunoglobulin levels(IgG - 200,IgM- below 10.0,IgA- 14.0) and we checked his immunoglobulin levels since he was falling sick from past 1 year(like eczema,cough and cold).So the doctor suspected he might be having CVID( Primary immunodeficiency) due to low immunoglobulin levels and suggested a genetic test since my grandfather also had low immunity in his late 50s but  the genetic test results showed no CVID( NO PATHOGENIC OR LIKELY PATHOGENIC VARIANTS CAUSATIVE OF THE REPORTED PHENOTYPE WERE DETECTED ) He repeatedly gets only a cough and cold(no fever )and takes almost 3 to 4 weeks to get recovered.Eczema also started very recently and it is healed now.No other symptoms apart from above symptoms So I want to know if he really has  CVID or any other immune disorder