PPM - Molecular Genetic Testing of CGG Repeat Expansions in Fragile X Syndrome-Checklist

Checklist

Pdf Summary

This document provides a checklist for documenting and recording important information during patient visits for molecular genetic testing of CGG repeat expansions in Fragile X Syndrome. The checklist includes steps such as documenting the patient's age, sex, and testing indication, verifying the quality and concentration of DNA, and ensuring appropriate controls are included in the analysis. It also emphasizes the need to consider factors such as X-inactivation in female samples, evaluate methylation status, and review for the possibility of mosaicism. The report should clearly state the detailed method used for testing and the analytical precision of allele size. The ACMG technical standards should be used for interpreting the CGG repeat expansion variant and appropriate terminology should be used when reporting results with mosaicism or unexpected findings. The possibility of confounding factors like sex chromosome variants should be documented and follow-up studies recommended. Test results with intermediate alleles should be interpreted as normal, while results with premutations should be considered abnormal. The potential limitations of chorionic villus samples should be mentioned and the report should include information about the availability of testing for at-risk family members. Finally, a recommendation for genetic consultation should be included in the report.

Keywords

checklist

molecular genetic testing

CGG repeat expansions

Fragile X Syndrome

testing indication

DNA quality

X-inactivation

mosaicism

analytical precision

genetic consultation