Cystic Fibrosis diagnosis-Delta 508 mutation

[engr_Shawon]

Hello, I am from Bangladesh. My son's age is about 7 months. We are consanguineous parents. As per X-ray report, his left lungs is collapsed. He already suffered from pneumonia twice in his 7 months. As per doctor's advice, we conduct the following diagnosis from India:
Quote:
Test:            Mutation analysis for common Cystic Fibrosis Mutation Delta F508
Result:         Negative for cystic Fibrosis Mutation Delta F508
Interpretation: The results indicate that the proband does not harbor the common mutation that is found in only 30-40% of patients in India. Rest of the patients have other mutations.
Recommendation: CFTR gene sequencing, If clinical diagnosis is firm, or sweat chloride are raised.
Genetic Counseling is advised.
Unquote
Can anybody explain, what does the report says? Is my son a cystic fibrosis patient/ carrier. Mentionable that we did not go for sweat chloride test and we parents never conduct the test for CF.
Thanks