Carey-Fineman-Ziter syndrome

Carey-Fineman-Ziter syndrome (CFZS), also known as myopathy-Möbius-Robin sequence, is a rare congenital disorder characterized by the combination of Möbius sequence (facial diplegia due to bilateral facial nerve palsy), Pierre Robin sequence (micrognathia, glossoptosis, and cleft palate), and a congenital nonprogressive myopathy. The condition is caused by biallelic pathogenic variants in the MYMK gene, which encodes myomaker, a protein essential for muscle cell fusion during development. The syndrome affects multiple body systems, most prominently the musculoskeletal and craniofacial structures, as well as the nervous system. Key clinical features include bilateral facial weakness with an expressionless or mask-like face, feeding and breathing difficulties in the neonatal period due to the Robin sequence, generalized hypotonia, and delayed motor milestones. Affected individuals may also exhibit short stature, failure to thrive, scoliosis, and variable intellectual development, though cognition is often preserved. Additional features can include pectus deformities, high-arched palate, and eye movement abnormalities. The myopathy is typically nonprogressive, and muscle biopsy may show nonspecific myopathic changes or features of reduced muscle fiber size. There is currently no cure or disease-specific treatment for Carey-Fineman-Ziter syndrome. Management is supportive and multidisciplinary, focusing on addressing feeding difficulties (which may require nasogastric tube feeding or gastrostomy), respiratory support, surgical correction of cleft palate, orthopedic management of scoliosis, physical therapy to optimize motor function, and speech therapy. Early intervention services and regular developmental assessments are recommended. Genetic counseling is important for affected families given the autosomal recessive inheritance pattern.

Common questions about Carey-Fineman-Ziter syndrome