X-linked dominant chondrodysplasia punctata with severe phenotype in a female fetus A case report

Rationale: X-linked dominant chondrodysplasia punctata type 2 (CDPX2) is a condition involving facial, skin, and skeletal dysplasia as a result of a mutation in emopamil binding protein (EBP). It usually presents with mild symptoms in female patients but is fatal in male patients. Patient concerns: A fetus was diagnosed with asymmetrical short limbs and a narrow and small thorax by prenatal ultrasound examination at 24+5 weeks gestation. The pregnancy was terminated at 27 weeks of gestation; gross examination, postnatal X-ray and, whole exome analysis were performed to clarify the diagnosis. Diagnosis: A provisional diagnosis of fatal skeletal dysplasia was given and the definite diagnosis of CDPX2 was based on postnatal X-ray and genetic testing of the aborted fetus. Intervention: The pregnancy was terminated at 27 weeks' gestation after a fetal ultrasound indicated a severe abnormal phenotype. Outcomes: Whole exome analysis of aborted tissue confirmed EBP mutation in this case. Unlike most case reports, this female patient presented a severe phenotype that was considered to be related to X-chromosome inactivation. Lessons: Chondrodysplasia punctata (CDP) should be considered if prenatal ultrasound shows high punctuate echoes at the metaphysis of long bones and asymmetrical short lower limbs. Postnatal X-ray and measurement of sterol levels in the amniotic fluid may aid in the diagnosis of CDP, but the condition can be confirmed with genetic testing of a blood sample or aborted tissue after delivery.