Medical Genetics

It is the specialty of medicine that involves the diagnosis, management, counseling and treatment of individuals and families with suspected or history of genetic disorders. 

When to consult a Medical Genetics specialist

•  Family history of a genetic disorder.
•  Intellectual disability
•  Developmental delay including speech delay 
•  Autism
•  Growth disorders i.e. failure to gain weight or height or obesity
•  Epilepsy i.e. fits/ seizures 
•  Brain abnormalities and nervous system disorders
•  Muscle disorders like weakness, abnormal walking or difficulty in walking, abnormalities of feet etc  
•  Short stature and other skeletal dysplasias 
•  Connective tissue disorders like rheumatoid arthritis, Lupus etc.
•  Cardiovascular diseases like heart defects, long QT syndrome etc
•  Sudden unexplained deaths in the family
•  Lung disorders like cystic fibrosis
•  Eye diseases like blindness, glaucoma, retinal dystrophy 
•  ENT disorders like deafness
•  Liver disorders and disorders of gastrointestinal tract 
•  Kidney and urinary tract abnormalities
•  Abnormalities of genitalia 
•  Hormonal abnormalities like diabetes
•  Disorders of sexual development
•  Immunity related disorders like recurrent infections, autoimmune disorders
•  Blood disorders like thalassemia or hemophilia 
•  Psychiatric disorders 
•  Skin conditions like white patches, albinism, icthhyosis etc.
•  All Cancers 

Reproductive Genetics i.e. Preconceptional, Prenatal and Antenatal Genetics

• Abnormalities that arise during pregnancy like abnormal screening tests i.e. double marker, triple marker or quadruple test, abnormal HPLC hemoglobin electrophoresis etc, TORCH test, ultrasound abnormalities like echogenic focus in  heart, echogenic bowel, choroid plexus cyst, dilated lateral ventricles, dilated pelvicalyceal system or any other structural malformation/ birth defects  in the baby.
• Advanced maternal age
• Inadvertent or accidental intake of any medicine during pregnancy (Teratogenesis)
• Exposure to any infection like rubella, chickenpox etc during pregnancy
• Identifying causes of infertility and recurrent abortions.
• Premarital and preconceptional counseling and testing
• Carrier screening
• Predictive testing and prevention

For all of the above: Prenatal diagnosis of chromosomal/genetic disorders in the unborn baby is possible.

If prenatal/ antenatal diagnosis is desired by the couple/family in view of any of the above, Genetic counseling can help them understand the risks, benefits and limitations of the prenatal diagnosis.

Medical Genetics also incorporates gene therapy, treatment for metabolic disorders, personalized medicine, predictive medicine and preventive medicine.

Medical Genetics is further supported by the genetic labs specialized for cytogenetics, molecular genetics, biochemical genetics and HLA genetics.

Cytogenetics is the study of chromosomes. It includes karyotype, FISH studies and newer techniques like array comparative genomic hybridization.  

Biochemical Genetics involves the diagnosis and management of inborn errors of metabolism in which patients have enzymatic deficiencies that perturb biochemical pathways involved in metabolism of carbohydrates, amino acids, and lipids. 

Molecular genetics involves the diagnosis of single gene disorders. Examples of single gene disorders include thalssemia, achondroplasia, cystic fibrosis, duchenne muscular dystrophy, hereditary breast cancer (BRCA1/2), huntington disease, marfan syndrome, noonan syndrome, and rett syndrome. Molecular tests are also used in the diagnosis of syndromes involving epigenetic abnormalities, such as Angelman syndrome, Beckwith-Wiedemann syndrome, Prader-willi syndrome, and uniparental disomy.

HLA genetics has a lot of role in organ transplants, genetic predisposition to certain disorders like diabetes, hypertension, psychiatric disorders, skin disorders etc.

The rapid advances in genetics has given a new hope for these so called “untreatable disorders”. 
Gene therapy, enzyme replacement therapy, specialized diets and drugs for certain metabolic disorders are now a reality.