Expert Reviewed By: Dr. Brandon Colby MD
Congenital Muscular Dystrophy (CMD) is a group of rare genetic disorders that cause muscle weakness and wasting from birth or early infancy. One such subtype is the ITGA7-related CMD, which results from mutations in the ITGA7 gene. This article aims to help you understand this disorder, its diagnosis, and the importance of genetic testing in managing the condition.
What is ITGA7-related Congenital Muscular Dystrophy?
ITGA7-related CMD is a subtype of CMD caused by mutations in the ITGA7 (Integrin Alpha-7) gene. This gene is responsible for producing a protein called integrin alpha-7, which plays a crucial role in muscle development and function. Mutations in the ITGA7 gene lead to a deficiency of this protein, causing muscle weakness and wasting.
ITGA7-related CMD is a rare disorder, with only a few cases reported in the medical literature. It is inherited in an autosomal recessive manner, meaning both parents must carry a copy of the mutated gene for the child to be affected.
Signs and Symptoms of ITGA7-related CMD
Individuals with ITGA7-related CMD typically present with muscle weakness and wasting from birth or early infancy. The severity of symptoms can vary greatly among affected individuals. Common signs and symptoms include:
- Generalized muscle weakness
- Delayed motor milestones, such as sitting and walking
- Joint contractures (stiffness)
- Respiratory difficulties
- Difficulty swallowing (dysphagia)
Some affected individuals may also have intellectual disability or developmental delays. The progression of the disorder can be variable, with some individuals experiencing a slow decline in muscle function, while others may have a more rapidly progressive course.
Diagnosing ITGA7-related CMD
Diagnosis of ITGA7-related CMD begins with a thorough clinical evaluation, including a detailed patient history and physical examination. The following tests may be performed to support the diagnosis:
- Muscle biopsy: A small sample of muscle tissue is removed and examined under a microscope to look for signs of muscle degeneration.
- Imaging studies: Magnetic resonance imaging (MRI) or computed tomography (CT) scans can help visualize muscle abnormalities.
- Electromyography (EMG): This test measures the electrical activity of muscles and can help determine the extent of muscle involvement.
However, the definitive diagnosis of ITGA7-related CMD relies on genetic testing to identify the specific mutations in the ITGA7 gene.
The Role of Genetic Testing in ITGA7-related CMD
Confirming the Diagnosis
Genetic testing is essential in confirming the diagnosis of ITGA7-related CMD. It involves analyzing the ITGA7 gene for the presence of disease-causing mutations. A positive genetic test result provides a definitive diagnosis, while a negative result may prompt further investigation into other possible causes of the patient's symptoms.
Carrier Testing and Family Planning
As ITGA7-related CMD is inherited in an autosomal recessive manner, carrier testing can be useful for family planning. Couples with a family history of the disorder or those who are known carriers can undergo genetic testing to determine the risk of having an affected child. This information can help couples make informed decisions about their reproductive options, such as prenatal testing or the use of assisted reproductive technologies.
Prenatal Testing
Prenatal testing for ITGA7-related CMD can be performed if both parents are known carriers of the disorder. This testing can be done through chorionic villus sampling (CVS) or amniocentesis, which involve analyzing fetal cells for the presence of ITGA7 gene mutations. Prenatal testing can help couples prepare for the birth of an affected child or make decisions about the pregnancy.
Conclusion
ITGA7-related CMD is a rare genetic disorder that causes muscle weakness and wasting from birth or early infancy. Genetic testing plays a crucial role in diagnosing the condition, carrier testing, and prenatal testing, ultimately improving the management and quality of life for affected individuals and their families.
About The Expert Reviewer
Dr. Brandon Colby MD is a US physician specializing in the personalized prevention of disease through the use of genomic technologies. He’s an expert in genetic testing, genetic analysis, and precision medicine. Dr. Colby is also the Founder of and the author of Outsmart Your Genes.
Dr. Colby holds an MD from the Mount Sinai School of Medicine, an MBA from Stanford University’s Graduate School of Business, and a degree in Genetics with Honors from the University of Michigan. He is an Affiliate Specialist of the American College of Medical Genetics and Genomics (ACMG), an Associate of the American College of Preventive Medicine (ACPM), and a member of the National Society of Genetic Counselors (NSGC)