A novel sequence variant in SFRP4 causing Pyle disease

Pyle disease (pyl) is an extremely rare disorder of irregular development of long bone. recently, homozygous mutations in secreted frizzled-related protein 4 gene (sfrp4) gene were found to underlie this condition. sequencing of coding regions of sfrp4 gene from an 11-year-old female with pyl was performed. a novel homozygous nonsense variant, c.183c>g (p.y61*) was observed. segregation analysis in the patient revealed a germline mutation, resulting in reduced protein formation. this is the second report from a fourth affected family with a sfrp4 mutation causing pyl disease.