Abstract.We report a male patient with type 1 thanatophoric dysplasia, now eight years old, having a mutation in the FGFR3 gene. Radiological examination at birth revealed that the ribs and the bones of the extremities were very short and vertebral bodies were greatly reduced in height with wide intervertebral spaces. was delivered after 48 weeks of gestation by Caesarean section. Apgar scores were 7 points at one min and 9 at five min. His birth weight was 2600 g, length 37.0 cm, head circumference 37.0 cm and chest circumference 26.8 cm. His short length, relatively large head, narrow thorax and short extremities were noted. Radiological examination (Fig. la) revealed that the ribs and the bones of the extremities were very short and vertebral bodies were greatly reduced in height with wide intervertebral spaces. The femurs were shaped like French telephone receivers. The mother was 20 years old, and the father 25 years when the patient was born. The parents were healthy and unrelated. There was no family history of skeletal deformity and the two younger siblings of the patient, a sister and a brother, were healthy.Because of respiratory insufficiency due to the narrow thorax, the patient has been intubated and supported by continuous mechanical ventilation