congenital myasthenic syndrome 3C

Congenital myasthenic syndrome 3C is a neuromuscular disorder that presents in early life with muscle weakness and impaired neuromuscular transmission. It is caused by compound heterozygous mutations in the CHRND gene, which plays a critical role in assembling components of the acetylcholine receptor at the neuromuscular junction. The condition manifests in infancy with feeding difficulties, poor suck, and respiratory challenges. Prevalence details have not been clearly established, and outcomes can vary considerably among affected individuals.

Clinically, congenital myasthenic syndrome 3C is characterized by a consistent presentation of muscle weakness, with all affected individuals experiencing dysphagia, facial palsy, feeding difficulties, poor suck, hypotonia, motor delay, respiratory insufficiency, weakness of facial musculature, ptosis, high palate, and increased muscle fatiguability. These symptoms are evident from early infancy, leading to challenges with feeding and breathing. Although these features are universally observed in this condition, the severity and impact on daily functioning vary among individuals. Not all individuals experience every symptom to the same degree, and overall presentations can differ from case to case.

The underlying cause of congenital myasthenic syndrome 3C is rooted in mutations of the CHRND gene, which is essential for proper formation of the acetylcholine receptor subunits at the neuromuscular junction. Disruption in the function of this protein impairs neuromuscular transmission, leading to the early-onset symptoms observed. The condition is inherited in an autosomal recessive pattern, meaning that an affected individual has received a mutated copy of the gene from each parent. Families are encouraged to seek genetic counseling to understand the implications for family planning and carrier status.

Currently, management of congenital myasthenic syndrome 3C centers on supportive care and symptom management. No treatments have been specifically approved for this condition, so therapeutic efforts are tailored to individual needs and typically involve a multidisciplinary team that may include neurologists, respiratory therapists, and physical therapists. Supportive measures often address feeding challenges, muscle weakness, and respiratory insufficiency, with regular surveillance playing a key role in long-term care. Patients are advised to discuss treatment options and the benefits of genetic counseling with their healthcare team.

The course of congenital myasthenic syndrome 3C is variable, with outcomes differing based on symptom severity and the effectiveness of supportive care. With current standards of care and multidisciplinary management, many affected individuals experience stabilization or improvement in symptoms, while others may require ongoing supportive interventions. That outcomes continue to evolve as advances in treatment and surveillance are integrated into clinical practice. Families are encouraged to connect with specialists and genetic counselors to better understand the potential course and to receive guidance tailored to their individual situation.