Hello Chaboobi,
Currently, as of Aug. 12, 2005, Colorado, Iowa, Mississippi, New
Jersey, New York, Oklahoma, South Carolina, Wisconsin, and Wyoming
are the US states that have laws in place mandating neonatal CF
testing. You can see by the chart on this page, that other states are
soon to implement testing, or test certain populations.
http://genes-r-us.uthscsa.edu/nbsdisorders.pdf
According to the Cystic Fibrosis Foundation, only 7 states test
newborns for CF. (This document is obviously older than the one above,
but contains good information!)
?The newborn screening tests for CF are not diagnostic tools. If the
initial screen is positive, then further tests are done to rule out or
confirm a CF diagnosis. Only a fraction of newborns with a positive
initial screen ultimately will be diagnosed with CF. Currently, seven
states conduct CF newborn screening in all newborns; three states
screen for CF in some hospitals or populations; while two more states
are now implementing CF screening programs. From 1990 to 1999, 1.46
million babies were screened for CF and 372 were ultimately diagnosed
with CF. CF is one of the most common disorders identified in the
newborn screening programs that include it in their testing.?
?CF is a genetic disease that affects approximately 30,000 people in
the United States. A defective gene causes the body to produce
abnormally thick, sticky mucus that leads to chronic and
life-threatening lung infections and impairs digestion. When the CF
Foundation was created in 1955, few children lived to attend
elementary school. Today, because of research and care supported by
the CF Foundation with money raised through donations from
individuals, corporations and foundations, the median age of survival
for people with CF is in the early 30s.
The mission of the Cystic Fibrosis Foundation is to assure the
development of the means to cure and control cystic fibrosis and to
improve the quality of life for those with the disease. For more
information on cystic fibrosis, call (800) FIGHT CF or visit
www.cff.org. ?
http://www.eurekalert.org/pub_releases/2004-10/cff-tcf101304.php
?To ensure that screening for cystic fibrosis results in more benefit
than harm, the CDC recommends that a deliberative process be followed.
First, before implementation of screening, states should consult with
other states that have experience in screening for cystic fibrosis as
well as cystic fibrosis specialists in their states. Second, they
recommend that states carefully address provider and public education,
infection control practices among providers of care to persons with
cystic fibrosis, and effective communication with families. Third,
they propose that state newborn screening programs develop systems in
collaboration with specialty care providers to track short-term and
long-term child outcomes and identify resources to support this
activity.?
http://www.findarticles.com/p/articles/mi_m3225/is_8_71/ai_n13795398#continue
?Abnormal results, and the strength of the test in predicting CF, is
based on where your child's test results fall in relation to the
values of all tested children to date and whether the test is positive
on repeat examination.
If your child's level of immunoreactive trypsinogen is greater than
140 ng/dL on the first screen, the test result is considered positive.
If your child's level is 120 ng/dL on the second screen, the second
test result is also considered positive.
Although these two test results indicate CF may exist, a sweat test
with a positive result confirms the diagnosis.?
http://www.georgetownuniversityhospital.org/body.cfm?id=555563&action=articleDetail&AEProductID=Adam2004_1&AEArticleID=003409
?When to get tested?
When a newborn infant has meconium ileus (no stools in the first 24 to
48 hours of life) or when a person has symptoms of CF (salty sweat,
persistent respiratory infections, wheezing, persistent diarrhea,
foul-smelling greasy stools, malnutrition, and vitamin deficiency); if
a person has a positive sweat chloride or IRT test or a close relative
who has been diagnosed with CF; when a patient is undergoing genetic
counseling and wants to find out if they are a CF carrier; or for
prenatal diagnosis?
http://www.labtestsonline.org/understanding/analytes/cf_gene/glance.html
There are pitfalls in CF testing, one of which is locating the child?s
pediatrician. Sometimes the results fall through the cracks. Delays in
results are usually caused by communication delays ? failure to enter
results in a computer, failure to promptly mail results, etc. If I
were the parent and did not have results back in a week, I would start
calling the pediatrician for results.
www.mostgene.org/gd/gdvol15f.htm
You are correct that IRT levels are tested. ?While newborn screening
for cystic fibrosis (CF) has been feasible since 1979 using the IRT
(immunoreactive trypsinogen test), and there have been slowly
accumulating observational data regarding the potential benefits of
such testing, it is not routinely performed in most states. In part,
this is because CF is different from the classic model of PKU newborn
screening in which a relatively simple intervention must be initiated
within a short time frame (weeks) in order to avoid a significant
complication (severe mental retardation). In contrast, cystic fibrosis
is a chronic and gradually progressive disease and the potential
benefit of newborn screening may be harder to discern.?
?Additionally, qualitative studies in Wisconsin and Australia
suggested that there are no significant negative psychosocial problems
in children identified with CF through screening. There may also be a
reduction in the parental anxiety since the time to diagnosis is less
with newborn screening, but this is difficult to assess for
methodological reasons.?
http://www.mostgene.org/gd/gdvol15d.htm
About the follow-up sweat test:
?The most common test for CF is called the sweat test. It measures the
amount of salt (sodium chloride) in the sweat. In this test, an area
of the skin (usually the forearm) is made to sweat by using a chemical
called pilocarpine and applying a mild electric current. To collect
the sweat, the area is covered with a gauze pad or filter paper and
wrapped in plastic. After 30 to 40 minutes, the plastic is removed,
and the sweat collected in the pad or paper is analyzed. Higher than
normal amounts of sodium and chloride suggest that the person has
cystic fibrosis.
The sweat test may not work well in newborns because they do not
produce enough sweat. In that case, another type of test, such as the
immunoreactive trypsinogen test (IRT), may be used. In the IRT test,
blood drawn 2 to 3 days after birth is analyzed for a specific protein
called trypsinogen. Positive IRT tests must be confirmed by sweat and
other tests.
Also, a small percentage of people with CF have normal sweat chloride
levels. They can only be diagnosed by chemical tests for the presence
of the mutated gene. Some of the other tests that can assist in the
diagnosis of CF are chest x-rays, lung function tests, and sputum
(phlegm) cultures. Stool examinations can help identify the digestive
abnormalities that are typical of CF.?
http://www.healingwell.com/library/cysticfibrosis/info2.asp
The CF gene
-----------
?The CF gene was identified in 1989. Since then, a great deal has been
learned about this gene and its protein product. The biochemical
abnormality in CF results from a mutation in a gene that produces a
protein responsible for the movement through the cell membranes of
chloride ions (a component of sodium chloride, or common table salt).
The protein is called CFTR--cystic fibrosis transmembrane regulator.
CFTR is present in cells that line the passageways of the lungs,
pancreas, colon, and genitourinary tract. When this protein is
abnormal, two of the hallmarks of CF result-blockage of the movement
of chloride ions and water in the lung and other cells and secretion
of abnormal mucus.
The mutation involved in CF causes the deletion of three of the base
pairs in the gene. This in turn, causes a loss in the CFTR protein of
an amino acid (the building blocks of proteins). Because phenylalanine
is located in position 508 of the protein chain, this mutant protein
is called deltaF508 CFTR.
However, deltaF508 CFTR accounts for only 70-80 percent of all CF
cases. Various other mutations-over 400 at the last count-seem to be
responsible for the remaining CF cases. Differences in disease
patterns seen in individuals and families probably result from the
combined effects of the particular mutation and various, but still
unknown, factors in the CF patient and his or her environment.?
http://www.healingwell.com/library/cysticfibrosis/info2.asp
?The CF gene mutation test identifies mutations in the CFTR gene on
chromosome 7. Each cell in the human body (except sperm and eggs) has
46 chromosomes (23 inherited from the mother and 23 from the father).
Genes on these chromosomes form the body?s blueprint for producing
proteins that control body functions. Cystic fibrosis is caused by a
mutation in a pair of genes located on chromosomes 7. Both copies
(alleles) of this gene must be abnormal to cause CF. If only one copy
of the gene pair is mutated, the patient will be a carrier. Carriers
are not ill, they do not have any symptoms, but they can pass their
abnormal CF gene copy on to their children.
To date, almost 1000 different mutations of the chromosome 7 gene have
been identified, but only a few of the mutations are common. The
majority of CF in the U.S. is caused by a mutation called deltaF508.?
http://www.labtestsonline.org/understanding/analytes/cf_gene/sample.html
Additional Information
======================
?Some people who suffer from repeated sinus infections may be
predisposed to them because they carry the same genetic mutation
responsible for cystic fibrosis (CF), new findings suggest.[1]
"For years we've known that children and adults with CF have severe
sinus infections--it's almost a given with the disease," said Garry R.
Cutting, MD, a geneticist at the McKusick-Nathans Institute of Genetic
Medicine, at the Johns Hopkins University School of Medicine, in
Baltimore. "We've long wondered if having just one mutant CFTR gene
has any health effects. Now we can confirm what we've suspected: Genes
may play a role in chronic sinus disease," Dr. Cutting said in an
interview with RESPIRATORY REVIEWS.?
http://www.respiratoryreviews.com/jan01/rr_jan01_genemutation.html
This is an interesting article of a study conducted in Scotland, using
the CF gene in a nasal spray!
?The results of the first Clinical Trial of Gene Therapy for CF in
Scotland were announced on 1 March 1997 (Porteous et al, Gene Therapy
4:210-218 (1997)). The results give rise to cautious optimism. The
study, led by Prof David Porteous , Dr Alastair Innes , Dr Andrew
Greening and their colleagues at Edinburgh's Western General Hospital,
involved a gene spray applied to the nose. The spray consists of a
working copy of the CF gene mixed with liposomes (fat droplets) which
'package and post' the gene into the cells lining the nose. The study
showed that the treatment was safe and works, but only briefly. Repeat
treatments would be needed. Further laboratory tests are underway and
an improved version of the treatment should be ready for testing in
the lung by the end of the year.
At the same time, results from a similar study with similar findings
were announced by an Oxford/Cambridge/Leeds/Manchester team (see Gill
et al, Gene Therapy 4:199-209 (1997)).
This gives further reassurance that this liposome based approach to
gene therapy may eventually become a useful form of treatment for CF.
Scotland in particular and the UK in general are at the international
forefront of this effort.?
http://www.genetics.med.ed.ac.uk/cysfib/background.shtml
Medine Plus
http://www.nlm.nih.gov/medlineplus/ency/article/003409.htm
The March of Dimes has an informational site here:
http://www.marchofdimes.com/professionals/681_1200.asp
I hope this has adequately answered your question. If any part of this
answer is unclear, please request an Answer Carification, before
rating, and I will be happy to respond.
Regards, Crabcakes
Search Terms
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Cystic Fibrosis + neonatal screening
States testing neonates + CF
CF testing + newborns
CF screening + States |
