CJI DY Chandrachud says daughters suffer rare muscle disorder: How to diagnose and manage it in time?

Dr Ishu Goyal, neurologist at Sir HN Reliance Foundation Hospital in Mumbai, admits that diagnosis poses a severe challenge with most clinicians often misdiagnosing it as a muscular disorder.

What is nemaline myopathy?

Nemaline myopathy is a rare genetic muscle disorder characterised by the presence of thread-like structures within muscle fibres affecting mobility and functionality. Since it is caused by several gene mutations, there are six types differentiated by the severity of muscle weakness. Understanding the genetic mutations is crucial for accurate diagnosis. The most severe forms can lead to significant muscle impairment, respiratory problems within the first year of life, potentially resulting in mortality. In contrast, the milder forms do not affect life expectancy. However, they do present challenges such as reduced muscle tone and weakness, impacting mobility and daily activities.

What are the current challenges in diagnosing nemaline myopathy and how do they impact timely identification of the disorder?

One of the primary challenges in diagnosing nemaline myopathy is its rarity. So it can be misdiagnosed as existing muscular disorders. This delay can be costly. Since a definitive diagnosis relies heavily on muscle biopsy results, it is crucial for clinicians to maintain a high level of awareness about this condition. If a patient presents with an atypical pattern of weakness, especially with a family history, clinicians should consider investigating nemaline myopathy.

What are the current treatment options for this condition?

Currently, treatment for nemaline myopathy is largely symptomatic and focuses on supportive care, including physiotherapy and muscle strengthening exercises. While certain drugs are in development aimed at targetitng the underlying genetic mutations, effective treatment options remain limited at this time.

How to differentiate nemaline myopathy from other neuro-muscular disorders?

Initially, a comprehensive history is taken to identify any hereditary patterns and the specific muscle groups affected. If the doctor suspects something, laboratory tests are conducted, including measuring muscle enzymes like creatine phosphokinase (CPK), which may be elevated in muscle disorders. We then perform electrophysiological tests, such as electromyography (EMG) and nerve conduction studies. Finally, we do a muscle biopsy.

What about treatment?

A multi-disciplinary treatment approach is crucial. The neurologist plays a vital role in the early diagnosis of the disorder, which is essential for effective management. Physiotherapists focus not only on improving limb strength but also on enhancing respiratory function. A pulmonologist may be involved to further support respiratory health. Psychologists and counselors can provide essential emotional support and strategies to encourage patients to cope with their illness. Furthermore, genetic counsellors are necessary to explore patterns of inheritance and provide guidance regarding future generations.