[1][2] It is characterized by blepharophimosis, microcephaly, micrognathia, multiple joint contractures, arachnodactyly, camptodactyly, kyphoscoliosis and delayed motor development and is often associated with cystic dysplastic kidneys, dextrocardia, Dandy–Walker malformation and agenesis of corpus callosum.

The most common signs at this state are multiple congenital joint contractures, dysmorphic features with mask-like face, blepharophimosis, ptosis, micrognathia, cleft or high arched palate, low-set ears, arachnodactyly, chest deformation as pectus, kyphoscoliosis and absent deep tendon reflexes are frequent minor malformations have also been described and consist of renal anomalies, cardiovascular abnormalities, hypospadias, omphalomesenteric duct, hypertrophic pyloric stenosis and duodenal bands, hypoplastic right lower lobe of the lung, displacement of the larynx to the right and vertebral abnormalities, cerebral malformations.

[4] The natural history of MWS is not well known: many patients died in infancy and clinical follow-up has been reported in few surviving adults.

[citation needed] Though the pathomechanism of Marden–Walker syndrome is unknown, it may be caused by a genetic defect which manifests as a dysfunctional molecular mechanism in the primary cilia structures of the cell.

The cilia defects adversely affect "numerous critical developmental signaling pathways" essential to cellular development.