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A 44-year-old member asked:

cystic fibrosis is caused by a recessive allele. is this true? so you could not know you have it?

2 doctor answers5 doctors weighed in
Dr. James Ferguson
Pediatrics 46 years experience
Many carry it: There are hundreds of thousands of people in the us that carry one recessive gene for cf. If they have children with another carrier, they have a 25% risk with every pregnancy of producing a kid with cf. If thier spouse is not a carrier, they have a 50% risk of passing the carrier state.
Dr. HARRY OPSIMOS
Pediatric Pulmonology 22 years experience
Carrier: If you are just a carrier you may very well not know it.

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Similar questions

A 23-year-old member asked:

Are there any alternative therapies available for cystic fibrosis?

2 doctor answers6 doctors weighed in
Dr. HARRY OPSIMOS
Pediatric Pulmonology 22 years experience
No: Maintaining good airway clearance and lung hygiene is key in cf. Treatment of lung infections is vital as well as routine follow-up with a CF center. Maintenance of an appropriate weight is also important. There are no known alternative therapies for cf.
CA
A 33-year-old member asked:

Could a 49 year old develop cystic fibrosis?

2 doctor answers5 doctors weighed in
Dr. Aaron Milstone
Pulmonology 27 years experience
Yes and No: Patients are born with cystic fibrosis. However it can take many years for the disease to become apparent in some patients. Thus, it is possible to be diagnosed with CF later in life but not to develop CF later in life.
Dr. William Walsh
Addiction Medicine 17 years experience
49 would be an usually late age to diagnose the disease, but a variant of the disease could appear that late in life, conceivably.
Jan 8, 2012
CA
A 36-year-old member asked:

How can I know if I have cystic fibrosis?

2 doctor answers11 doctors weighed in
Dr. HARRY OPSIMOS
Pediatric Pulmonology 22 years experience
Need to be tested: You can only be diagnosed with cystic fibrosis (CF) by testing. A sweat chloride testing must be done, which is considered the gold standard test for cf.
A 48-year-old member asked:

How typical are false positives on cystic fibrosis tests?

2 doctor answers4 doctors weighed in
Dr. David Escobar
Dr. David Escobar answered
Family Medicine 9 years experience
Not Typical: Certain rare conditions can also lead to high sweat chloride levels (the gold standard test for cystic fibrosis). However, these rare conditions (there's a list) will cause the patient to exhibit different symptoms than those consistent with cystic fibrosis, so the sweat chloride test is considered to be reliable in diagnosing CF in conjunction with the patient's history and physical exam.
CA
A 33-year-old member asked:

How common are false positives with cystic fibrosis tests?

3 doctor answers12 doctors weighed in
Dr. Robert Fink
Pediatrics 47 years experience
Uncommon: False positive sweat tests to diagnose CF are very uncommon. Genetic testing should never have false positive results. However, newborn screening for CF is frequently positive in babies who have one copy of the CF gene (cf carriers). A positive newborn screening for CF is not a diagnosis of CF unless the baby has a positive sweat test or positive genetic testing with two mutations identified.

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Last updated Feb 5, 2017
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