Cystic Fibrosis Common Mutation Screen

Introduction

Cystic Fibrosis, caused by mutations in the cystic fibrosis transmembrane regulator gene (CFTR at 7q31-32), is the most frequent autosomal recessive genetic disorder in caucasians of European origin. The incidence in the UK in this ethnic group is 1/2500. More than 1000 different mutations are known with the spectrum and frequency varying with ethnic background.

Referral information

Confirmation of diagnosis where CF is clinically suspected. Testing of individuals in whom a diagnosis of a mild variant form of CF is suspected (for example, congenital bilateral absence of the vas deferens, CBAVD). Carrier screening of the partner and relatives of an individual who carries one or more common CF mutations. Carrier testing in pregnant couples with fetal echogenic bowel. Pre-natal diagnosis where specific parental mutations have been identified. For fetal echogenic bowel referrals, parental samples taken before PND allow a more rapid result. Ethnicity and whether the individual’s parents are consanguineous are required to calculate accurate risk figures. Where there is a family history we require either the mutation test results or a sample from the index case. We follow the UK Clinical Genetic Society guidelines on screening children and discourage carrier testing for minors in this condition.

Price & reporting times

NHS referrals to this service are paid for where there is an existing specialist commissioning contract for genetic testing. In other cases please contact the lab for prices.

Test NHS Price (£ ) Non NHS Price (£) TRT
Common mutation screening POA POA 28 cd
Single mutation test POA POA 28 cd
Urgent pregnancy (common mutation screening) POA POA 14 cd
Prenatal diagnosis POA POA 3 cd

Test validation & quality assurance - information for users

The test detects >90% of CF mutations in the North West Caucasian population. A negative test result does not exclude CF. In cases with a strong suspicion of CF the sweat chloride test should be undertaken prior to genetic testing.

Sample requirements

Pre-natal: amniotic fluid (minimum 15ml)/chorionic villus biopsy (CVB) (minimum 10mg) sample plus 4ml EDTA maternal blood sample

Post-natal: 4ml EDTA blood sample

Referral guidelines

Please see our referral guidelines for more information.

OMIM Number(s) - 219700

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