Medical Genetics: Diagnosis and Management of Hereditary Disorders
Medical genetics encompasses a vast field dedicated to the diagnosis and management of hereditary disorders, which arise from genetic alterations. Unlike human genetics, which is focused on research that may or may not apply to medicine, medical genetics emphasizes the practical application of genetics in healthcare.
Scope and Subspecialties
Medical genetics encompasses a wide range of areas, including clinical practice, genetic counseling, and research into genetic disorders. Its scope includes birth defects, intellectual disabilities, cancer genetics, and prenatal diagnosis. Recent advances in genetics have revealed genetic etiologies for various medical conditions, expanding the relevance of the field to areas such as cardiovascular, endocrine, and psychiatric medicine.
Clinical Genetics
Clinical genetics specializes in the evaluation and management of individuals with hereditary disorders. Subspecialties within clinical genetics include prenatal, pediatric, and adult genetics, as well as cancer genetics. Genetic counselors play a crucial role in providing non-directive counseling and assessing family risk factors associated with genetic disorders.
Metabolic/Biochemical Genetics
Metabolic genetics focuses on the diagnosis and management of inborn errors of metabolism, which are caused by enzymatic deficiencies that disrupt metabolic pathways. Examples include galactosemia, phenylketonuria, and urea cycle disorders.
Cytogenetics
Cytogenetics studies chromosomes and chromosomal abnormalities, using techniques such as karyotyping and array comparative genomic hybridization. Cytogenetics plays an important role in prenatal diagnosis, as well as in the identification of chromosomal disorders associated with cancer.
Molecular Genetics
Molecular genetics involves the identification and analysis of DNA mutations that underlie genetic disorders. It is used in the diagnosis of single gene disorders such as achondroplasia, cystic fibrosis, and Huntington disease.
Mitochondrial Genetics
Mitochondrial genetics concerns the diagnosis and management of mitochondrial disorders, which arise from defects in the mitochondrial DNA and result in impaired energy production.
Current Practice and Diagnostic Evaluation
Patients seeking genetic evaluation undergo a diagnostic process tailored to their presenting symptoms and signs. The geneticist determines a differential diagnosis and recommends appropriate tests. These tests may include chromosomal studies, biochemical analyses, and molecular studies.
Treatments and Ethical Considerations
Genetic disorders are typically caused by alterations in genes or chromosomes, which are present in every cell of the body. Currently, there is no cure for most genetic disorders, but treatments can be available to manage symptoms and improve the quality of life. The advancements in genetic technologies have raised ethical, legal, and social implications, highlighting the importance of careful consideration in the use of genetic information.