A Rare Case: Genetically Confirmed Newborn with Thanatophoric Dysplasia Type 1 (TD1)

Abstract

Thanatophoric dysplasia (TD) is the most frequent sporadic lethal skeletal dysplasia with an incidence about 1 in 17.000–50.000 births. Diagnosis of TD can made at prenatal period by ultrasound and immediately after birth based on clinical examination, radiologic studies, histopathology and molecular analysis. Thanatophoric dysplasia is subdivided in two dinstinct phenotypes: 1) Thanatophoric dysplasia type 1 (TD1) is characterized by curved ‘‘telephone receiver’’ femora and mild craniosynostosis or 2) Thanatophoric dysplasia type 2 (TD2) includes straight femora and cloverleaf skull. Girl baby was born from 44 years old female with 35th weeks of gestation (WOG) with non-consanguineous marriage. The patient looked lethargic accompanied with rapid breathing with chest indrawing. On examination the patient looked dysmorphic, large head with frontal bossing without clover leaf skull, upper and lower limbs were extremely short. Babygram showed head was large, thoracic cavity was small and narrow, the ribs were short, and “telephone receiver” like curved femora was noted. Mutational analysis confirmed a heterozygous allele p.Tyr373Cys mutation in the Fibroblast Growth Factor Receptor 3 (FGFR3) gene. The patient was diagnosed with TD1. The general condition and respiratory distress did not improve and the patient was died on the sixteenth days of hospitalization. Thanatophoric dysplasia type 1 was rare disease and lethal case. The diagnosis based on clinical examination, radiologic studies, histopathology and molecular analysis. Lethality in thanatophoric dysplasia is caused mainly by respiratory distress due to a narrow thorax.