Meckel Syndrome 8 (MKS8) is an autosomal recessive multisystem disorder that represents a severe form of ciliopathy in humans.  It is defined by the tetrad of encephalocele, polydactyly, and renal and biliary ductal dysplasia, although clinical heterogeneity is known to exist even within the same families.  Because of their serious health problems, most individuals with MKS8 die before or shortly after birth.

MKS8 is particularly prevalent with a reported incidence as high as 1:3,500 in newborns.  It is inherited in an autosomal recessive pattern with six genes described to date.  It is suggested by studies in mice that the type I membrane protein that belongs to the tectonic family may be involved in hedgehog signaling, and essential for ciliogenesis.  

MKS8 is an autosomal recessive multisystem disorder.  A splice site mutation in the TCTN2 gene has been identified by homozygosity mapping in a family with MKS8 that completely abolished normal splicing and created two aberrant transcripts. The mutation was found to segregate with disease in the family in homozygosity and was not observed in 192 ethnically matched controls.