Thanatophoric Dwarfism - A Lethal Skeletal Dysplasia

Thanatophoric dwarfism is a lethal, congenital skeletal dysplasia caused by mutations in the FGFR3 gene. It is characterized by extreme shortening of the limbs, narrow thorax, macrocephaly, and distinctive facial and skeletal abnormalities. Its rarity and high perinatal lethality make early diagnosis and genetic counseling critical.We report the case of a preterm female infant delivered vaginally at 33 weeks of gestation with no prior family history of congenital anomalies. Antenatal ultrasonography showed micromelic limb shortening, severe thoracic hypoplasia, macrocephaly, and polyhydramnios. On examination, the neonate presented with dysmorphic features, notably relative macrocephaly, depressed nasal bridge, narrow thorax, and short limbs with redundant skin folds. Radiographs confirmed features consistent with thanatophoric dysplasia type 2, including straight femora and a cloverleaf-shaped skull. Despite supportive measures, the infant was not revived.Prenatal diagnosis of thanatophoric dwarfism allows for prompt counseling, anticipatory guidance, and informed decision-making. This case highlights the importance of detailed antenatal imaging and genetic evaluation for rare skeletal dysplasias.