New autosomal recessive syndrome of severe microcephaly and skeletal anomalies including posterior rib-gap defects.

We describe two female fetuses conceived by a nonconsanguineous couple. The pregnancies were interrupted at 31 and 26 weeks of gestation, respectively, because of severe microcephaly. Postmortem X-ray and autopsy studies showed in both fetuses: 1) severe intrauterine growth retardation; 2) facial anomalies characterized by severe microcephaly, sloping forehead, low set and posteriorly angulated ears, prominent eyes, down-slanting palpebral fissures, large nose, small mouth with full lips, and mild microretrognathia; 3) severe brain hypoplasia that was more pronounced in the second fetus; 4) severe rib hypoplasia with posterior rib-gap defects and in case 2 hypoplasia of several bones (right clavicle, right radius and ulna, several phalanges of hands and feet); 5) contracture at large joints. No other visceral malformations were observed, and chromosomes were normal in patient 2 and parents. This phenotype has some similarities with different syndromic entities but an identical malformation syndrome seems not to have been described previously. Autosomal recessive inheritance is the most likely cause of this putative "new syndrome."