2. Common Disorders/Screening (CF, Hemophilia, Hemoglobin Disorders, Venous Thromboembolism) Ondemand-M02 GFeldman Common Disorders Notes

M02 GFeldman Common Disorders Notes

Pdf Summary

This document discusses various topics related to laboratory genetics and genomics, specifically focusing on the molecular diagnosis of common disorders. It covers differentiating diagnostic testing from carrier screening, the pathogenesis and molecular genetic testing for common single gene disorders such as cystic fibrosis and hemophilia, residual risk calculation, molecular methodologies used in testing, evaluation of test performance, and interpretation of test results. <br /><br />The document provides an overview of diagnostic testing, which is used to confirm a suspected diagnosis or phenotype, and carrier screening, which is primarily used to offer information about the risk of having a child with a specific genetic disorder. It explains the molecular techniques used in identifying pathogenic variants, including polymerase chain reaction, Sanger sequencing, and targeted next-generation sequencing. The advantages and disadvantages of various molecular methodologies are also discussed. <br /><br />The document goes on to discuss the reasons and scenarios in which carrier screening is recommended, and highlights the availability of carrier testing for other family members once a mutation is identified. It also mentions guidelines from professional organizations that recommend carrier screening but clarifies that it will not specifically discuss these guidelines in the lecture.<br /><br />The document then delves into specific examples of genetic disorders, such as cystic fibrosis, hemoglobinopathies, and hemophilia, providing information about their clinical features, prevalence, and available molecular diagnostic approaches. It also discusses thrombophilias, including Factor V Leiden, prothrombin 20210A mutation, and methylenetetrahydrofolate reductase (MTHFR) polymorphisms.<br /><br />The document concludes by summarizing the recommendations of the American College of Medical Genetics and Genomics (ACMG) regarding MTHFR polymorphism testing, stating that it should not be ordered as part of the clinical evaluation for thrombophilia or recurrent pregnancy loss.<br /><br />Overall, this document provides a comprehensive overview of molecular diagnosis in laboratory genetics and genomics, focusing on common disorders and the methodologies used in testing.

Keywords

laboratory genetics

genomics

molecular diagnosis

common disorders

diagnostic testing

carrier screening

single gene disorders

molecular methodologies

genetic disorders

ACMG recommendations