X-linked dominant chondrodysplasia punctata 2 with severe phenotype in one female fetus: a case report

We reported a female fetus diagnosed with X-linked dominant chondrodysplasia punctata 2 with severe phenotype. The fetus was found with abnormal short limbs, thick metaphysis on the right lower limb and a narrow and small thorax by prenatal ultrasound at 24+5 weeks of gestation. Non-invasive prenatal test indicated the risks of trisomies 21, 18 and 13 were low. The pregnancy was terminated at 27 weeks of gestation and postnatal X-ray imaging showed that the fetus had short femur and humerus, a narrow and small thorax, thickened metaphysis with a "splashed paint spot" pattern, and asymmetric shortened lower limbs. Whole-exome analysis showed that the fetus carried a heterozygous pathogenic mutation c.440G>A (p.Arg147His) in the EBP gene. The mutation was confirmed to be a de novo mutation as neither of her parents carried the same mutation. Thus, the patient was diagnosed as having X-linked dominant chondrodysplasia punctata 2. The severe phenotype of this case migh be related to random X chromosome inactivation. Key words: Chondrodysplasia punctata; Ultrasonography, prenatal; Whole exome sequencing; Female