Can adult onset cystic fibrosis occur to male 44 old please?

Yes: I would use a term "mild" or "atypical" form of cystic fibrosis. Cystic fibrosis is caused by mutation involving cftr gene, and there are a few hundred different mutations. Atypical or mild form of CF manifest at a later age than in infancy as often seen in classic form, and mild in symptoms.

Yes: Adult onset CF may present with milder symptoms leading to a late diagnosis of the disease. There are many gene mutations and clinical presentations of the disease. A good resource is cff.Org i hope this helps.