Genetic diseases are disorders caused by abnormalities in an individual’s DNA. These abnormalities can be due to mutations in a single gene (monogenic disorders), multiple genes (polygenic disorders), or changes in the number or structure of chromosomes (chromosomal disorders). Genetic diseases can be inherited from one or both parents (hereditary/familial diseases) or can occur spontaneously during an individual’s development (de novo mutations).
Examples of genetic diseases include cystic fibrosis, sickle cell anemia, Huntington’s disease, Down syndrome, and various types of cancers that have a genetic component. These conditions can affect different systems of the body, leading to a wide range of symptoms and health issues.
Genetic Testing
Genetic testing involves analyzing an individual’s DNA to identify mutations that may cause genetic diseases. This testing can be performed at any stage of life, from prenatal to adulthood, and serves various purposes:
Diagnosis: Identifying the genetic cause of a disease in symptomatic individuals.
Carrier Testing: Determining if a person carries a gene mutation that could be passed to their children.
Prenatal Testing: Checking the fetus for genetic conditions during pregnancy.
Newborn Screening: Testing newborns for certain genetic disorders early in life.
Predictive and Pre-symptomatic Testing: Identifying genetic mutations that may increase the risk of developing certain diseases later in life.
Genetic testing is a powerful tool in modern medicine, enabling early diagnosis and personalized treatment plans. It also provides valuable information for family planning and managing the health of future generations. However, genetic testing involves ethical considerations, and individuals are advised to undergo genetic counseling to understand the implications of testing and its results fully before seeking a test.
At CCMB, we have excellent infrastructure, the latest technology, and skilled professionals. We offer a wide range of testing services with ethical and sensitive reporting of results. Our reports are detailed, well-summarized, and include relevant literature, following the latest guidelines. Reports undergo multiple levels of scrutiny, including review by a medical geneticist, to ensure the accuracy and safety of the genetic information.
The following tests and services are available with us
Cytogenetics is a branch of genetics that focuses on the study of chromosomes, the structures within cells that contain DNA. Cytogenetic testing combines aspects of cytology (the study of cells) and genetics to identify chromosomal abnormalities that contribute to genetic disorders. Chromosomal abnormalities can occur in several ways, including
Numerical Abnormalities: Changes in the number of chromosomes, such as trisomy 21 (Down syndrome), where there is an extra copy of chromosome 21, or monosomy, where a chromosome is missing.
Structural Abnormalities: Changes in the structure of chromosomes, which can involve deletions, duplications, inversions, or translocations of chromosome segments.
Tests available:
Karyotype
This technique involves staining and visualizing chromosomes under a microscope to identify numerical and large structural abnormalities.
Sample and transport requirements for Karyotyping:
3ml blood sample in a sealed, labelled Heparin (green top) vacutainer.
[Note: The sample should be stored and transported at 4°C and should reach us within 24-48 hours of collection]
Fluorescence In Situ Hybridization (FISH):
FISH uses fluorescent probes that bind to specific DNA sequences on chromosomes. This technique allows for the detection of smaller chromosomal abnormalities and gene rearrangements that are not visible with traditional karyotyping.
Sample and transport requirements for FISH:
Chorionic villus sample (11-14 weeks of pregnancy) with visible villi in normal saline
20-30mL of Amniotic fluid (16-18 weeks of pregnancy)
3ml blood sample in a sealed, labelled Heparin (green top) vacutainer. [Note: The sample should be stored and transported at 4°C and should reach us within24-48 hours of collection]
Optical Genome Mapping:
This advanced technique allows for the detection of structural variations in the genome with high resolution. It can identify complex rearrangements that other methods might miss.
Sample and transport requirements for Optical Genome Mapping:
3-6ml blood sample in a sealed, labelled EDTA (purple top) vacutainer.
[Note: The sample should be stored and transported at 4°C immediately after collection and should reach the lab within 48-72 hours of collection.]
Several genetic disorders are known to result from the defects in a single gene. Using various molecular biology tools, we provide genetic diagnostic services to identify such variations that are responsible for the disease in the patient. Targeted testing approaches are available for close to 50 such monogenic disorders. In addition, CCMB also offers Next Generation Sequencing (NGS) services for diagnosis of other rare genetic disorders using Whole Exome Sequencing (WES) and Whole Genome Sequencing (WGS) approaches.
Sample and transport requirements for Karyotyping:
3ml blood sample in a sealed, labelled Heparin (green top) vacutainer.
[Note: The sample should be stored and transported at 4°C immediately after collection and should reach the lab within 48-72 hours of collection
For Prenatal testing:
Chorionic villus sample (11-14 weeks of pregnancy) with visible villi in normal saline
20-30mL of Amniotic fluid (16-18 weeks of pregnancy [Note: The sample should be stored and transported at 4°C immediately after collection and should reach the lab within 24 – 48 hours of collection.]
Instructions for sending samples for Genetic Testing
The following requirements are essential to ensure timely testing and reporting of samples received at CCMB.
Duly filled case information sheet with an informative pedigree
Relevant test reports (genetic test reports of other affected members of the family (if available) or other non-genetic testing reports that have raised clinical suspicio
Every prenatal sample should be accompanied by duly filled and signed Form F & G in addition to the above-mentioned documents as per the Pre-Conception and Pre-Natal Diagnostics and Techniques (PC-PNDT) Act of 1994 (amended in 2003).
Payment Details
Payment may be made via cash onsite/ demand draft “IN FAVOUR OF DIRECTOR CCMB, PAYABLE AT HYDERABAD”
Genetic counselling is a crucial service that helps individuals and families navigate the complex and often challenging landscape of genetic disorders. CCMB offers genetic counselling (both pre-test and post-test counselling) to help determine the genetic nature of a clinical condition based on available clinical history and pedigree analysis. By providing risk assessment and appropriate genetic information, we help the patients make informed decisions about their health and the health of their families.
Note: To avail of genetic counselling services at CGDC, please make an appointment in advance by calling our landline number 040-27195612 (Monday to Friday between 10 am and 6 pm). Symptomatic individuals in the family should be present during the meeting with the Clinical Geneticist for evaluation. Please bring all available medical records to the visit.
Genetic testing involves analyzing DNA, RNA, or proteins to identify changes or mutations that could lead to genetic disorders. It helps diagnose conditions, assess risk, and guide treatment decisions.
Genetic testing can provide valuable information for diagnosing genetic disorders, assessing risk for certain diseases, making informed reproductive choices, and tailoring medical treatments to your genetic profile.
Genetic testing typically involves a sample of blood, saliva, or tissue. The DNA is then extracted and analyzed using various techniques such as PCR, DNA sequencing, etc., to detect genetic mutations.
The accuracy of genetic testing depends on the type of test and the condition being tested for. Most genetic tests have high sensitivity and specificity, but no test is 100% accurate. False positives and false negatives can occur.
The turnaround time for genetic test results varies. Some tests may provide results within a few days, while others, especially those involving comprehensive sequencing, may take several weeks.
Genetic test results are often complex and should be interpreted by a healthcare professional, such as a genetic counselor or medical geneticist. They can explain the implications of the results, including risks, management options, and recommendations for family members.
Genetic test results for inherited conditions typically do not change over time. However, new research and advancements in genetic testing may lead to reclassification of variants or updated interpretations of previous results.
? Insurance coverage for genetic testing varies by provider and policy. Some tests are covered if they are deemed medically necessary. It is important to check with your insurance company regarding specific coverage details.
Genetic counseling is a process that provides information, support, and guidance on genetic conditions and testing. It helps individuals understand the implications of genetic testing, make informed decisions, and cope with the emotional impact of test results.
Ethical considerations include informed consent, privacy and confidentiality, potential for discrimination, and the psychological impact of knowing one’s genetic risk. It is important to discuss these issues with a healthcare provider or genetic counselor.
No, genetic testing cannot predict all diseases. While it can identify mutations associated with specific genetic disorders, many diseases are influenced by multiple genetic and environmental factors, making prediction complex.
If your results are positive for a genetic mutation, consult with your healthcare provider or genetic counselor. They can provide information on the condition, discuss potential treatment or management options, and offer support in coping with the results.
Alternatives to genetic testing include detailed family medical history assessments, clinical evaluations, and imaging or biochemical tests. These methods can provide valuable information but may not offer the same level of specificity as genetic testing.