Rhizomelic chondrodysplasia punctata type Ⅰ in a fetus due to novel pathogenic mutation in PEX7 gene / 中华围产医学杂志

ABSTRACT

We report a case of a fetus with rhizomelic chondrodysplasia punctata type Ⅰ. Ultrasound examination of the pregnant women at 23 weeks of gestation showed multiple fractures in bilateral femurs, thick metaphysis, severely short, thickened and curved bilateral humerus with multiple fracture images, some of which were callu formation after fracture. The pregnancy was terminated at 23 +2 gestational weeks, samples of fetal skin tissue were taken after birth, and parental peripheral blood was collected for whole exome sequencing, which revealed a frameshift mutation c.179delT (p.F61Lfs*13) in the PEX7 gene of chromosome 6, and the heterozygous deletion (141 kb) occurred in the region of chromosome 6 137105182-137245871, covering the pathogenic gene PEX7. The analysis of parental samples suggested that the mutations were compound heterozygous mutations, none of which had been previously reported and were determined to be pathogenic mutations. The severe clinical phenotype of this case may be caused by severe damage of PEX7 gene contributed by the frameshift mutation and large fragment deletion mutations.