Osteocraniostenosis is a lethal skeletal dysplasia characterized by a cloverloaf anomaly, facial dysmorphism, limb shortness, splenic hypo/aplasia and radiological anomalies including thin tubular bones with flared metaphyses and deficient calvarial mineralization.
First described in 1989, less than 20 cases have been reported so far.
This multiple congenital anomalies syndrome is characterized by dysmorphic features of the fetus and the newborn: the skull is misshapen, combining acrocephaly and cloverleaf deformity, fontanelles are very large; facial dysmorphism includes midface hypoplasia with telecanthus, short upturned nose, short philtrum, small inverted V-shaped mouth and low-set ears; limbs are also affected with bowed forearms, micromelia and acromicria with brachydactyly.
Etiology of osteocraniostenosis is unknown, but a study revealed the potential role of a collagen type's disequilibrium in bone anomalies. Some histological findings report growth plate disorganization and adjacent diaphyseal ossification.
Diagnosis is based mainly on radiological and pathological examination. Radiological examination reveals hypomineralisation of the skull, flat and dense vertebral bodies, thin tubular bones with flared and dense metaphyses, brachymetacarpia and brachyphalangy with with ''diabolo appearance '' and lack of ossification of the distal phalanges. The spleen is hypoplasic or even absent. Fractures are frequent.
Differential diagnosis includes the hypo/akinesia sequence, Hallermann-Streiff-François syndrome and other gracile bone dysplasias and some cases of osteogenesis imperfecta with slender bones (see this term).
Prenatal ultrasound observation reveals micromelic dwarfism, cranial deformity, mild intra-uterine growth retardation and sometimes fractures.
Inheritance is still unclear, but autosomal recessive inheritance is likely.
There is no treatment for osteocraniostenosis.
Prognosis is very poor as most cases are stillborn or die in their first days of life.
Last update: October 2012