CYSTIC FIBROSIS

Cystic Fibrosis (CF) is a recessively inherited disorder usually presenting in children and young adults. It results from mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene on chromosome 7. Manifestations of the disease include disrupted exocrine function of the pancreas, intestinal glands (meconium ileus), biliary tree (biliary cirrhosis), bronchial glands (chronic broncho- pulmonary infection with emphysema), and sweat glands (high sweat electrolyte with depletion in a hot environment). It can also affect fertility in both males and females.

Although many hundreds of CF mutations have now been identified, the number accounting for the majority of CF cases is very much smaller. There is however, some variation in the profile of common mutations between different populations. Consequently, we offer two assays providing differing levels of mutation screening. CF Assay 1, screens for a total of 10 potential CTFR mutations (see table 1) including the UK's 3 most common (Schwarz et al, 1995 Hum.Mutat. 6:326-333). CF Assay 2, screens for a total of 31 potential CFTR mutations (see table 2) and includes 24 of the most common worldwide (Kazazian, H.H. 1994, Hum.Mutat. 4:167-177).

Table 1:

deltaF508

G542X

1717-1G>A

G551D

R560T

deltaI507

N1303K

W1282X

R553X

3905insT

Table 2:

deltaF508

1717-1G>A

R560T

3849+4A>G

3905insT

R117H

R347P

1898+1G>A

deltaI507

G542X

S549R

R1162X

N1303K

Y122X

R347H

2183AA>G

Q493X

G551D

S549N

3659delC

G85E

711+1G>T

R334W

2789+5G>A

V520F

R553X

3849+10kbC>T

W1282X

621+1G>T

1078delT

A455E

-

 

The cost of CF Assay 1 is £75 per sample, CF Assay 2 costs £150 per sample*. Both whole blood or cheek swab specimens can be accepted for either assay. If CF Assay 1 has already been performed, but no mutations were detected, CF Assay 2 can be performed on request for an additional £100 (ie. £175 in total).

Testing is indicated for prospective parents where either have a family history of CF, or for those who are considering fertility treatment (this is because some CF mutations are associated with infertility, thus couples experiencing fertility problems are more likely to be CF mutation carriers than random members of the population). It is also indicated for all clinically symptomatic children, and all children that have known CF carrier parents or previously diagnosed siblings. An initial request for CF Assay 2 is recommended for individuals of non-european origin or for relevant individuals where testing for more common mutations has already proven negative.

*Please enquire for bulk or contract discounts.