Prenatal onset infantile cortical hyperostosis

Prenatal onset infantile cortical hyperostosis is a rare variant of infantile cortical hyperostosis, however, it is a more severe and lethal form and newborns die early postnatally.

Pathology

Both sporadic and autosomal recessive inheritance have been suggested. A missense mutation in the gene (COL1A1) responsible for type-I collagen synthesis is believed to be responsible.

Histopathologically, it is similar to the infantile cortical hyperostosis.

Radiographic features

Ultrasound

The disease can be diagnosed by antenatal ultrasonography and the following features may be observed:

• short, angulated bones
• irregular diaphyses
• hydrops fetalis
• pulmonary hypoplasia
• polyhydramnios

Plain radiograph

Postmortem plain x-ray may show cortical hyperostosis of long bones, ribs, and mandible.

Differential diagnosis

Antenatal USG imaging differentials include:

• osteogenesis imperfecta
• campomelic dysplasia
• hypophosphatasia

The typical differentiating feature of prenatal onset hyperostosis from the above-mentioned entities is the absence of fractures.