Thanatophoric dysplasia is a lethal skeletal dysplasia manifested by short extremities which is caused by a mutation in the fibroblast growth factor receptor 3 (FGFR3) gene. Characteristically, macrocephaly, narrow thorax, flattening in the vertebrae, bowing in the femur with short and flat extremities is seen. Herein, we present a case of thanatophoric dysplasia type 1 diagnosed by typical clinical and radiological findings, and FGFR3 gene analysis.

The patient born at the 34th gestational week with a 2160 g birth weight was found to have macrocephaly, marked forehead, narrow thorax, curved and short extremities on physical examination. Skeletal X-rays showed platyspondyly in the vertebral corpus, short ribs and short long tubular bones. Molecular genetic analysis revealed a heterozygous p.R248C (c.742C> T) mutation in the FGFR3 gene exon 7.

Thanatophoric dysplasia should be considered in the differential diagnosis of cases with skeletal dysplasia.