Short rib‐polydactyly syndrome, type 3 with chondrocytic inclusions: Report of a case and review of the literature

Abstract

Abstract A newborn with severely shortened ribs, short limbs, and postaxial polydactyly died shortly after birth. Postmortem roentgenograms established the diagnosis of type 3 short rib‐polydactyly (SRP) syndrome as described by Naumoff and associates. Histopathologic study showed the chondrocytes to contain previously undescribed cytoplasmic inclusion bodies that were PAS‐positive and diastase‐resistant. The material appeared by staining reactions to be a glycoprotein that was seen electron microscopically to accumulate within dilated cisterns of rough endoplasmic reticulum. Similar cytoplasmic inclusions have not been seen in other short rib‐polydactyly syndromes, including SRP types 1 and 2, Jeune syndrome, and Ellis‐van Creveld syndrome. It is often difficult to differentiate cases of type 3 and type 1 (Saldino‐Noonan) syndrome, and in the past the diagnosis has sometimes been confused. A review of previously reported cases showed that type 3 syndrome rarely (1 in 13) had cloacal developmental abnormalities, which are invariably present in patients with type 1 syndrome. Type 3 is also associated with a lower incidence of congenital heart disease, and cardiac malformations, when present, differ from those associated with type 1 syndrome. Both type 3 and type 1 SRP syndromes are transmitted in autosomal recessive fashion. Type 3 SRP syndrome has had an equal sex distribution, although type 1 has so far been reported to occur only in girls. Further investigation with additional patients is necessary to verify the above preliminary findings.