Definition:

Sedaghatian type spondylometaphyseal dysplasia (SMDS) is a rare type of lethal congenital severe spondylometaphyseal dysplasia characterised by severe metaphyseal chondrodysplasia with mild limb shortening, platyspondyly, delayed epiphyseal ossification, irregular iliac crests, and pulmonary haemorrhage. Most of the patients had been reported to have a short life span, and died shortly after birth due to respiratory failure. Half of infants with SMDS are reported to have central nervous system (CNS) malformations consistent with abnormal neuronal migration, including agenesis of the corpus callosum, pronounced frontotemporal pachygyria, simplified gyral pattern, partial lissencephaly, and severe cerebellar hypoplasia. It has been reported that recessive truncating mutations in the GPX4 gene are the cause of SMDS.