congenital myasthenic syndrome 4C

Congenital myasthenic syndrome 4C is a neuromuscular disorder characterized by early-onset muscle weakness caused by defects at the postsynaptic neuromuscular junction. It results from mutations in the CHRNE gene, which is essential for proper neuromuscular signaling. Affected individuals typically present during infancy with symptoms such as ptosis, ophthalmoparesis, and fatigable weakness. While precise prevalence data is not available, the condition is considered rare.

The clinical picture of congenital myasthenic syndrome 4C is defined by consistent findings including fatigable weakness, ptosis, and ophthalmoparesis, with electrophysiological studies showing a decremental response of the compound muscle action potential on repetitive nerve stimulation. These hallmark features usually prompt early clinical evaluation and genetic testing. Not all individuals experience every symptom to the same extent, and severity can vary considerably.

This condition is caused by homozygous or compound heterozygous mutations in the CHRNE gene, which plays a crucial role in the function of the neuromuscular junction. It is inherited in an autosomal recessive manner, meaning that both parents typically carry one copy of the altered gene and there is a 25% chance with each pregnancy for the child to be affected. Families are encouraged to seek genetic counseling to better understand the implications for family planning.

Currently, management focuses on supportive care and symptom management, with treatment plans tailored to each individual’s needs. A multidisciplinary team, which may include neurologists, physical therapists, and genetic counselors, is typically involved in ongoing care. Patients should discuss treatment options with their healthcare team to determine the most appropriate strategies, and genetic counseling is recommended to help families understand the condition and associated recurrence risks.

The course of congenital myasthenic syndrome 4C varies among affected individuals, with some experiencing relatively stable symptoms over time and others having a more variable clinical course. Outcomes described in medical literature continue to evolve as standards of care improve. Families often find it helpful to connect with specialists familiar with this condition and to seek genetic counseling for ongoing guidance. Severity and symptoms vary widely between individuals, making personalized care and monitoring essential.