Decoding Dysmetria: Understanding, Diagnosing, and Genetic Testing

Expert Reviewed By: ⁠Dr. Brandon Colby MD

Understanding Dysmetria

Dysmetria is a type of neurological disorder that affects a person’s ability to control the range and force of their movements. This condition is often associated with cerebellar dysfunction, which is the part of the brain responsible for coordinating and regulating muscle activity. Dysmetria can manifest in various ways, including difficulty in controlling the force, speed, and direction of a movement, leading to overshooting or undershooting the intended target.

One specific form of dysmetria is found in patients with spinocerebellar ataxia 6 (SCA6), a hereditary neurodegenerative disorder. A study has shown that force dysmetria in SCA6 patients correlates with functional capacity, meaning that the severity of dysmetria is directly related to the patient’s ability to perform daily tasks.

Diagnosing Dysmetria

Diagnosing dysmetria involves a thorough neurological examination by a healthcare professional. The examination may include tests to assess muscle strength, reflexes, coordination, balance, and gait. In some cases, imaging studies, such as magnetic resonance imaging (MRI) or computed tomography (CT) scans, may be required to evaluate the cerebellum and other brain structures.

Genetic testing can also play a crucial role in diagnosing dysmetria, especially in cases where the condition is inherited. For instance, in autosomal dominant congenital nonprogressive spinocerebellar ataxia, a study has identified heterozygous mutations in the ITPR1 gene as the cause of the disorder. In such cases, genetic testing can confirm the diagnosis and help guide treatment and management decisions.

Genetic Testing for Dysmetria

Identifying the Genetic Cause

Genetic testing can help identify the specific gene mutations responsible for dysmetria in a patient. This information is vital for understanding the underlying cause of the disorder and can aid in determining the most appropriate treatment options. For example, in cases of autosomal dominant congenital nonprogressive spinocerebellar ataxia, identifying the ITPR1 gene mutation can confirm the diagnosis and help guide treatment decisions.

Family Planning and Prenatal Testing

For individuals with a family history of dysmetria or other inherited neurological disorders, genetic testing can provide valuable information for family planning. Couples can undergo carrier testing to determine if they carry the gene mutations responsible for the condition. This information can help them make informed decisions about having children and the potential risks of passing on the disorder to their offspring.

Prenatal testing can also be performed to determine if a fetus is affected by the disorder. This can help parents prepare for the potential challenges of raising a child with dysmetria and make informed decisions about their pregnancy.

Guiding Treatment and Management

While there is currently no cure for dysmetria, genetic testing can help guide treatment and management decisions. By identifying the specific gene mutations responsible for the disorder, healthcare professionals can better understand the underlying cause and develop targeted therapies to address the patient’s symptoms. In some cases, this may involve medications to control muscle movements or physical therapy to improve coordination and balance.

Additionally, genetic testing can help identify potential complications or adverse effects related to certain medications. For example, a case report highlights rare but debilitating neurological adverse effects of ranolazine in an elderly patient with renal impairment. In such cases, genetic testing can help healthcare professionals make informed decisions about medication management to minimize the risk of adverse effects.

Conclusion

Dysmetria is a neurological disorder that affects a person’s ability to control the range and force of their movements. Genetic testing plays a crucial role in diagnosing and managing the condition, helping to identify the underlying cause, guide treatment decisions, and provide valuable information for family planning. As our understanding of the genetic factors contributing to dysmetria continues to grow, so too will our ability to develop targeted therapies and improve the quality of life for those affected by this challenging disorder.

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)