Sporadic case of dyssegmental dysplasia with antenatal presentation.

Dyssegmental dysplasia is a rare micromelic dwarfism with characteristic clinical and radiological features. In skeletal dysplasias with severe micromelia prenatal detection of affected fetuses is possible using ultrasonography. However, prenatal diagnosis is usually performed after the occurrence of a previous case in the family. In this case dyssegmental dysplasia was detected prenatally in the first child of unaffected related (first cousins) parents. Fetal ultrasonographic examination in the 33rd week of gestation revealed a normal biparietal diameter of 94 mm and pronounced shortening of the extremities with femurs of 19 mm. The femurs were bowed. The spine showed severe malsegmentation. At radiological examination the long bones showed a dumbbell configuration especially in the longer extremities. The spine showed severe malsegmentations including coronal and sagittal clefting and multiple outsize vertebrae. The pelvis had very narrow sacrosciatic notches and rounded iliac wings. This case supports the autosomal recessive inheritance and demonstrates the possibility of prenatal diagnosis in non familial cases in this type of micromelic dwarfism.