This is the current release of the guideline.

The quality of evidence (I-III) and classification of recommendations (A-E) are defined at the end of the "Major Recommendations."

1. Carrier screening for Tay-Sachs disease (TSD) (II-2A), Canavan disease, and familial dysautonomia (FD) should be offered to Ashkenazi Jewish couples. (III-A)
2. Carrier screening for other disorders seen with increased frequency in Ashkenazi Jewish individuals (e.g., Bloom syndrome, Fanconi anemia, Gaucher disease, glycogen storage disease type 1a, mucolipidosis type IV, Niemann-Pick disease type 1A, and cystic fibrosis [CF]) should be offered when there is a positive family history. (III-A)
3. When only one member of a couple is of Ashkenazi Jewish ancestry, screening should be offered for TSD only. (II-2A)
4. When only one member of a couple is of Ashkenazi Jewish ancestry, screening should not be offered for Canavan disease or familial dysautonomia (FD) because of a low carrier frequency and limitations of carrier screening (low detection rate in individuals of non-Ashkenazi Jewish ancestry). (III-D)
5. When both partners are carriers of the same autosomal recessive condition, they have a 25% risk of having an affected child. They should be referred for genetic counselling, either before conception or prenatally. Prenatal diagnosis would be offered and performed according to the patient's informed decision. Prenatal diagnosis would consist of DNA analysis done on cells obtained by chorionic villus sampling or amniocentesis. (II-3A)

Definitions

Quality of Evidence Assessment*

I: Evidence obtained from at least one properly designed randomized controlled trial.

II-1: Evidence obtained from well-designed controlled trials without randomization.

II-2: Evidence obtained from well-designed cohort (prospective or retrospective) or case–control analytic studies, preferably from more than one center or research group.

II-3: Evidence obtained from comparisons between times or places with or without the intervention. Dramatic results from uncontrolled experiments (such as the results of treatment with penicillin in the 1940s) could also be included in this category.

III: Opinions of respected authorities, based on clinical experience, descriptive studies, or reports of expert committees.

Classification of Recommendations*

1. There is good evidence to support the recommendation that the condition be specifically considered in a periodic health examination
2. There is fair evidence to support the recommendation that the condition be specifically considered in a periodic health examination.
3. There is poor evidence regarding the inclusion or exclusion of the condition in a periodic health examination.
4. There is fair evidence to support the recommendation that the condition not be considered in a periodic health examination.
5. There is good evidence to support the recommendation that the condition be excluded from consideration in a periodic health examination.

*The quality of evidence reported in these guidelines has been adapted from The Evaluation of Evidence criteria described in the Canadian Task Force on the Periodic Health Exam.

**Recommendations included in these guidelines have been adapted from the Classification of Recommendations criteria described in the Canadian Task Force on the Periodic Health Exam.

A clinical algorithm "Approach to carrier screening with negative family history" is provided in the original guideline document.

The type of supporting evidence is identified and graded for each recommendation (see "Major Recommendations").

Not applicable: The guideline was not adapted from another source.

2006 Apr

Canadian College of Medical Geneticists - Professional Association
Society of Obstetricians and Gynaecologists of Canada - Medical Specialty Society

Society of Obstetricians and Gynaecologists of Canada

Society of Obstetricians and Gynaecologists of Canada Genetics Committee
Canadian College of Medical Geneticists Prenatal Diagnosis Committee

Principal Authors: Sylvie Langlois, MD, FRCPC, FCCMG, Vancouver BC; R. Douglas Wilson (Chair), MD, FRCSC, Philadelphia PA

Genetics Committee Members: R. Douglas Wilson (Chair), MD, FRCSC, Philadelphia PA; Victoria M. Allen, MD, MSc, FRCSC, Halifax NS; Claire Blight, RN, Halifax NS; Valerie A. Désilets, MD, FRCSC, Montreal QC; Alain Gagnon, MD, FRCSC, Vancouver BC; Sylvie Langlois, MD, FRCPC, Vancouver BC; Gregory J. Reid, MD, FRCSC, Winnipeg MB Anne Summers, MD, FRCPC, Toronto ON; Philip Wyatt, MD, PhD, North York ON

Prenatal Diagnosis Committee Members: Sylvie Langlois (Chair), MD, FRCPC, FCCMG, Vancouver BC; David Chitayat, MD, FRCPC, FCCMG, Toronto ON; Albert E. Chudley, MD, FRCPC, FCCMG, Winnipeg MB; Sandra Farrell, MD, FRCPC, FCCMG, Mississauga ON; Michael T. Geraghty, MD, FRCPC, FCCMG, Ottawa ON; Chumei Li, MD, PhD, FRCPC, FCCMG, Toronto ON; Sarah M. Nikkel, MD, FRCPC, FCCMG, Ottawa ON; Anne Summers, MD, FRCPC, FCCMG, Toronto ON; Frederique Tihy, PhD, FCCMG, Montreal QC

Not stated

This is the current release of the guideline.

None available

None available

This NGC summary was completed by ECRI Institute on March 9, 2009. The information was verified by the guideline developer on March 25, 2009.

This NGC summary is based on the original guideline, which is subject to the guideline developer's copyright restrictions.